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                                 l2arc_add_vdev(spa, vd);
1484                 }
1485         }
1486 
1487         /*
1488          * Purge vdevs that were dropped
1489          */
1490         for (i = 0; i < oldnvdevs; i++) {
1491                 uint64_t pool;
1492 
1493                 vd = oldvdevs[i];
1494                 if (vd != NULL) {
1495                         ASSERT(vd->vdev_isl2cache);
1496 
1497                         if (spa_l2cache_exists(vd->vdev_guid, &pool) &&
1498                             pool != 0ULL && l2arc_vdev_present(vd))
1499                                 l2arc_remove_vdev(vd);
1500                         vdev_clear_stats(vd);
1501                         vdev_free(vd);
1502                 }
1503         }
1504 
1505         if (oldvdevs)
1506                 kmem_free(oldvdevs, oldnvdevs * sizeof (void *));
1507 
1508         if (sav->sav_config == NULL)
1509                 goto out;
1510 
1511         sav->sav_vdevs = newvdevs;
1512         sav->sav_count = (int)nl2cache;
1513 
1514         /*
1515          * Recompute the stashed list of l2cache devices, with status
1516          * information this time.
1517          */
1518         VERIFY(nvlist_remove(sav->sav_config, ZPOOL_CONFIG_L2CACHE,
1519             DATA_TYPE_NVLIST_ARRAY) == 0);
1520 
1521         l2cache = kmem_alloc(sav->sav_count * sizeof (void *), KM_SLEEP);
1522         for (i = 0; i < sav->sav_count; i++)
1523                 l2cache[i] = vdev_config_generate(spa,
1524                     sav->sav_vdevs[i], B_TRUE, VDEV_CONFIG_L2CACHE);
1525         VERIFY(nvlist_add_nvlist_array(sav->sav_config,
1526             ZPOOL_CONFIG_L2CACHE, l2cache, sav->sav_count) == 0);
1527 out:
1528         for (i = 0; i < sav->sav_count; i++)
1529                 nvlist_free(l2cache[i]);
1530         if (sav->sav_count)
1531                 kmem_free(l2cache, sav->sav_count * sizeof (void *));
1532 }
1533 
1534 static int
1535 load_nvlist(spa_t *spa, uint64_t obj, nvlist_t **value)
1536 {
1537         dmu_buf_t *db;
1538         char *packed = NULL;
1539         size_t nvsize = 0;
1540         int error;
1541         *value = NULL;
1542 
1543         VERIFY(0 == dmu_bonus_hold(spa->spa_meta_objset, obj, FTAG, &db));
1544         nvsize = *(uint64_t *)db->db_data;
1545         dmu_buf_rele(db, FTAG);
1546 
1547         packed = kmem_alloc(nvsize, KM_SLEEP);
1548         error = dmu_read(spa->spa_meta_objset, obj, 0, nvsize, packed,
1549             DMU_READ_PREFETCH);
1550         if (error == 0)
1551                 error = nvlist_unpack(packed, nvsize, value, 0);
1552         kmem_free(packed, nvsize);
1553 
1554         return (error);
1555 }
1556 
1557 /*
1558  * Checks to see if the given vdev could not be opened, in which case we post a
1559  * sysevent to notify the autoreplace code that the device has been removed.
1560  */
1561 static void
1562 spa_check_removed(vdev_t *vd)
1563 {
1564         for (int c = 0; c < vd->vdev_children; c++)
1565                 spa_check_removed(vd->vdev_child[c]);
1566 
1567         if (vd->vdev_ops->vdev_op_leaf && vdev_is_dead(vd) &&
1568             !vd->vdev_ishole) {
1569                 zfs_post_autoreplace(vd->vdev_spa, vd);
1570                 spa_event_notify(vd->vdev_spa, vd, ESC_ZFS_VDEV_CHECK);
1571         }
1572 }
1573 
1574 /*
1575  * Validate the current config against the MOS config
1576  */
1577 static boolean_t
1578 spa_config_valid(spa_t *spa, nvlist_t *config)
1579 {
1580         vdev_t *mrvd, *rvd = spa->spa_root_vdev;
1581         nvlist_t *nv;
1582 
1583         VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nv) == 0);
1584 
1585         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1586         VERIFY(spa_config_parse(spa, &mrvd, nv, NULL, 0, VDEV_ALLOC_LOAD) == 0);
1587 
1588         ASSERT3U(rvd->vdev_children, ==, mrvd->vdev_children);
1589 
1590         /*
1591          * If we're doing a normal import, then build up any additional
1592          * diagnostic information about missing devices in this config.
1593          * We'll pass this up to the user for further processing.
1594          */
1595         if (!(spa->spa_import_flags & ZFS_IMPORT_MISSING_LOG)) {
1596                 nvlist_t **child, *nv;
1597                 uint64_t idx = 0;
1598 
1599                 child = kmem_alloc(rvd->vdev_children * sizeof (nvlist_t **),
1600                     KM_SLEEP);
1601                 VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0);
1602 
1603                 for (int c = 0; c < rvd->vdev_children; c++) {
1604                         vdev_t *tvd = rvd->vdev_child[c];
1605                         vdev_t *mtvd  = mrvd->vdev_child[c];
1606 
1607                         if (tvd->vdev_ops == &vdev_missing_ops &&
1608                             mtvd->vdev_ops != &vdev_missing_ops &&
1609                             mtvd->vdev_islog)
1610                                 child[idx++] = vdev_config_generate(spa, mtvd,
1611                                     B_FALSE, 0);
1612                 }
1613 
1614                 if (idx) {
1615                         VERIFY(nvlist_add_nvlist_array(nv,
1616                             ZPOOL_CONFIG_CHILDREN, child, idx) == 0);
1617                         VERIFY(nvlist_add_nvlist(spa->spa_load_info,
1618                             ZPOOL_CONFIG_MISSING_DEVICES, nv) == 0);
1619 
1620                         for (int i = 0; i < idx; i++)
1621                                 nvlist_free(child[i]);
1622                 }
1623                 nvlist_free(nv);
1624                 kmem_free(child, rvd->vdev_children * sizeof (char **));
1625         }
1626 
1627         /*
1628          * Compare the root vdev tree with the information we have
1629          * from the MOS config (mrvd). Check each top-level vdev
1630          * with the corresponding MOS config top-level (mtvd).
1631          */
1632         for (int c = 0; c < rvd->vdev_children; c++) {
1633                 vdev_t *tvd = rvd->vdev_child[c];
1634                 vdev_t *mtvd  = mrvd->vdev_child[c];
1635 
1636                 /*
1637                  * Resolve any "missing" vdevs in the current configuration.
1638                  * If we find that the MOS config has more accurate information
1639                  * about the top-level vdev then use that vdev instead.
1640                  */
1641                 if (tvd->vdev_ops == &vdev_missing_ops &&
1642                     mtvd->vdev_ops != &vdev_missing_ops) {
1643 
1644                         if (!(spa->spa_import_flags & ZFS_IMPORT_MISSING_LOG))
1645                                 continue;
1646 
1647                         /*
1648                          * Device specific actions.
1649                          */
1650                         if (mtvd->vdev_islog) {
1651                                 spa_set_log_state(spa, SPA_LOG_CLEAR);
1652                         } else {
1653                                 /*
1654                                  * XXX - once we have 'readonly' pool
1655                                  * support we should be able to handle
1656                                  * missing data devices by transitioning
1657                                  * the pool to readonly.
1658                                  */
1659                                 continue;
1660                         }
1661 
1662                         /*
1663                          * Swap the missing vdev with the data we were
1664                          * able to obtain from the MOS config.
1665                          */
1666                         vdev_remove_child(rvd, tvd);
1667                         vdev_remove_child(mrvd, mtvd);
1668 
1669                         vdev_add_child(rvd, mtvd);
1670                         vdev_add_child(mrvd, tvd);
1671 
1672                         spa_config_exit(spa, SCL_ALL, FTAG);
1673                         vdev_load(mtvd);
1674                         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1675 
1676                         vdev_reopen(rvd);
1677                 } else if (mtvd->vdev_islog) {
1678                         /*
1679                          * Load the slog device's state from the MOS config
1680                          * since it's possible that the label does not
1681                          * contain the most up-to-date information.
1682                          */
1683                         vdev_load_log_state(tvd, mtvd);
1684                         vdev_reopen(tvd);
1685                 }
1686         }
1687         vdev_free(mrvd);
1688         spa_config_exit(spa, SCL_ALL, FTAG);
1689 
1690         /*
1691          * Ensure we were able to validate the config.
1692          */
1693         return (rvd->vdev_guid_sum == spa->spa_uberblock.ub_guid_sum);
1694 }
1695 
1696 /*
1697  * Check for missing log devices
1698  */
1699 static boolean_t
1700 spa_check_logs(spa_t *spa)
1701 {
1702         boolean_t rv = B_FALSE;
1703 
1704         switch (spa->spa_log_state) {
1705         case SPA_LOG_MISSING:
1706                 /* need to recheck in case slog has been restored */
1707         case SPA_LOG_UNKNOWN:
1708                 rv = (dmu_objset_find(spa->spa_name, zil_check_log_chain,
1709                     NULL, DS_FIND_CHILDREN) != 0);
1710                 if (rv)
1711                         spa_set_log_state(spa, SPA_LOG_MISSING);
1712                 break;
1713         }
1714         return (rv);
1715 }
1716 
1717 static boolean_t
1718 spa_passivate_log(spa_t *spa)
1719 {
1720         vdev_t *rvd = spa->spa_root_vdev;
1721         boolean_t slog_found = B_FALSE;
1722 
1723         ASSERT(spa_config_held(spa, SCL_ALLOC, RW_WRITER));
1724 
1725         if (!spa_has_slogs(spa))
1726                 return (B_FALSE);
1727 
1728         for (int c = 0; c < rvd->vdev_children; c++) {
1729                 vdev_t *tvd = rvd->vdev_child[c];
1730                 metaslab_group_t *mg = tvd->vdev_mg;
1731 
1732                 if (tvd->vdev_islog) {
1733                         metaslab_group_passivate(mg);
1734                         slog_found = B_TRUE;
1735                 }
1736         }
1737 
1738         return (slog_found);
1739 }
1740 
1741 static void
1742 spa_activate_log(spa_t *spa)
1743 {
1744         vdev_t *rvd = spa->spa_root_vdev;
1745 
1746         ASSERT(spa_config_held(spa, SCL_ALLOC, RW_WRITER));
1747 
1748         for (int c = 0; c < rvd->vdev_children; c++) {
1749                 vdev_t *tvd = rvd->vdev_child[c];
1750                 metaslab_group_t *mg = tvd->vdev_mg;
1751 
1752                 if (tvd->vdev_islog)
1753                         metaslab_group_activate(mg);
1754         }
1755 }
1756 
1757 int
1758 spa_offline_log(spa_t *spa)
1759 {
1760         int error;
1761 
1762         error = dmu_objset_find(spa_name(spa), zil_vdev_offline,
1763             NULL, DS_FIND_CHILDREN);
1764         if (error == 0) {
1765                 /*
1766                  * We successfully offlined the log device, sync out the
1767                  * current txg so that the "stubby" block can be removed
1768                  * by zil_sync().
1769                  */
1770                 txg_wait_synced(spa->spa_dsl_pool, 0);
1771         }
1772         return (error);
1773 }
1774 
1775 static void
1776 spa_aux_check_removed(spa_aux_vdev_t *sav)
1777 {
1778         for (int i = 0; i < sav->sav_count; i++)
1779                 spa_check_removed(sav->sav_vdevs[i]);
1780 }
1781 
1782 void
1783 spa_claim_notify(zio_t *zio)
1784 {
1785         spa_t *spa = zio->io_spa;
1786 
1787         if (zio->io_error)
1788                 return;
1789 
1790         mutex_enter(&spa->spa_props_lock);       /* any mutex will do */
1791         if (spa->spa_claim_max_txg < zio->io_bp->blk_birth)
1792                 spa->spa_claim_max_txg = zio->io_bp->blk_birth;
1793         mutex_exit(&spa->spa_props_lock);
1794 }
1795 
1796 typedef struct spa_load_error {
1797         uint64_t        sle_meta_count;
1798         uint64_t        sle_data_count;
1799 } spa_load_error_t;
1800 
1801 static void
1802 spa_load_verify_done(zio_t *zio)
1803 {
1804         blkptr_t *bp = zio->io_bp;
1805         spa_load_error_t *sle = zio->io_private;
1806         dmu_object_type_t type = BP_GET_TYPE(bp);
1807         int error = zio->io_error;
1808 
1809         if (error) {
1810                 if ((BP_GET_LEVEL(bp) != 0 || DMU_OT_IS_METADATA(type)) &&
1811                     type != DMU_OT_INTENT_LOG)
1812                         atomic_add_64(&sle->sle_meta_count, 1);
1813                 else
1814                         atomic_add_64(&sle->sle_data_count, 1);
1815         }
1816         zio_data_buf_free(zio->io_data, zio->io_size);
1817 }
1818 
1819 /*ARGSUSED*/
1820 static int
1821 spa_load_verify_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
1822     const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg)
1823 {
1824         if (bp != NULL) {
1825                 zio_t *rio = arg;
1826                 size_t size = BP_GET_PSIZE(bp);
1827                 void *data = zio_data_buf_alloc(size);
1828 
1829                 zio_nowait(zio_read(rio, spa, bp, data, size,
1830                     spa_load_verify_done, rio->io_private, ZIO_PRIORITY_SCRUB,
1831                     ZIO_FLAG_SPECULATIVE | ZIO_FLAG_CANFAIL |
1832                     ZIO_FLAG_SCRUB | ZIO_FLAG_RAW, zb));
1833         }
1834         return (0);
1835 }
1836 
1837 static int
1838 spa_load_verify(spa_t *spa)
1839 {
1840         zio_t *rio;
1841         spa_load_error_t sle = { 0 };
1842         zpool_rewind_policy_t policy;
1843         boolean_t verify_ok = B_FALSE;
1844         int error;
1845 
1846         zpool_get_rewind_policy(spa->spa_config, &policy);
1847 
1848         if (policy.zrp_request & ZPOOL_NEVER_REWIND)
1849                 return (0);
1850 
1851         rio = zio_root(spa, NULL, &sle,
1852             ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE);
1853 
1854         error = traverse_pool(spa, spa->spa_verify_min_txg,
1855             TRAVERSE_PRE | TRAVERSE_PREFETCH, spa_load_verify_cb, rio);
1856 
1857         (void) zio_wait(rio);
1858 
1859         spa->spa_load_meta_errors = sle.sle_meta_count;
1860         spa->spa_load_data_errors = sle.sle_data_count;
1861 
1862         if (!error && sle.sle_meta_count <= policy.zrp_maxmeta &&
1863             sle.sle_data_count <= policy.zrp_maxdata) {
1864                 int64_t loss = 0;
1865 
1866                 verify_ok = B_TRUE;
1867                 spa->spa_load_txg = spa->spa_uberblock.ub_txg;
1868                 spa->spa_load_txg_ts = spa->spa_uberblock.ub_timestamp;
1869 
1870                 loss = spa->spa_last_ubsync_txg_ts - spa->spa_load_txg_ts;
1871                 VERIFY(nvlist_add_uint64(spa->spa_load_info,
1872                     ZPOOL_CONFIG_LOAD_TIME, spa->spa_load_txg_ts) == 0);
1873                 VERIFY(nvlist_add_int64(spa->spa_load_info,
1874                     ZPOOL_CONFIG_REWIND_TIME, loss) == 0);
1875                 VERIFY(nvlist_add_uint64(spa->spa_load_info,
1876                     ZPOOL_CONFIG_LOAD_DATA_ERRORS, sle.sle_data_count) == 0);
1877         } else {
1878                 spa->spa_load_max_txg = spa->spa_uberblock.ub_txg;
1879         }
1880 
1881         if (error) {
1882                 if (error != ENXIO && error != EIO)
1883                         error = SET_ERROR(EIO);
1884                 return (error);
1885         }
1886 
1887         return (verify_ok ? 0 : EIO);
1888 }
1889 
1890 /*
1891  * Find a value in the pool props object.
1892  */
1893 static void
1894 spa_prop_find(spa_t *spa, zpool_prop_t prop, uint64_t *val)
1895 {
1896         (void) zap_lookup(spa->spa_meta_objset, spa->spa_pool_props_object,
1897             zpool_prop_to_name(prop), sizeof (uint64_t), 1, val);
1898 }
1899 
1900 /*
1901  * Find a value in the pool directory object.
1902  */
1903 static int
1904 spa_dir_prop(spa_t *spa, const char *name, uint64_t *val)
1905 {
1906         return (zap_lookup(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
1907             name, sizeof (uint64_t), 1, val));
1908 }
1909 
1910 static int
1911 spa_vdev_err(vdev_t *vdev, vdev_aux_t aux, int err)
1912 {
1913         vdev_set_state(vdev, B_TRUE, VDEV_STATE_CANT_OPEN, aux);
1914         return (err);
1915 }
1916 
1917 /*
1918  * Fix up config after a partly-completed split.  This is done with the
1919  * ZPOOL_CONFIG_SPLIT nvlist.  Both the splitting pool and the split-off
1920  * pool have that entry in their config, but only the splitting one contains
1921  * a list of all the guids of the vdevs that are being split off.
1922  *
1923  * This function determines what to do with that list: either rejoin
1924  * all the disks to the pool, or complete the splitting process.  To attempt
1925  * the rejoin, each disk that is offlined is marked online again, and
1926  * we do a reopen() call.  If the vdev label for every disk that was
1927  * marked online indicates it was successfully split off (VDEV_AUX_SPLIT_POOL)
1928  * then we call vdev_split() on each disk, and complete the split.
1929  *
1930  * Otherwise we leave the config alone, with all the vdevs in place in
1931  * the original pool.
1932  */
1933 static void
1934 spa_try_repair(spa_t *spa, nvlist_t *config)
1935 {
1936         uint_t extracted;
1937         uint64_t *glist;
1938         uint_t i, gcount;
1939         nvlist_t *nvl;
1940         vdev_t **vd;
1941         boolean_t attempt_reopen;
1942 
1943         if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_SPLIT, &nvl) != 0)
1944                 return;
1945 
1946         /* check that the config is complete */
1947         if (nvlist_lookup_uint64_array(nvl, ZPOOL_CONFIG_SPLIT_LIST,
1948             &glist, &gcount) != 0)
1949                 return;
1950 
1951         vd = kmem_zalloc(gcount * sizeof (vdev_t *), KM_SLEEP);
1952 
1953         /* attempt to online all the vdevs & validate */
1954         attempt_reopen = B_TRUE;
1955         for (i = 0; i < gcount; i++) {
1956                 if (glist[i] == 0)      /* vdev is hole */
1957                         continue;
1958 
1959                 vd[i] = spa_lookup_by_guid(spa, glist[i], B_FALSE);
1960                 if (vd[i] == NULL) {
1961                         /*
1962                          * Don't bother attempting to reopen the disks;
1963                          * just do the split.
1964                          */
1965                         attempt_reopen = B_FALSE;
1966                 } else {
1967                         /* attempt to re-online it */
1968                         vd[i]->vdev_offline = B_FALSE;
1969                 }
1970         }
1971 
1972         if (attempt_reopen) {
1973                 vdev_reopen(spa->spa_root_vdev);
1974 
1975                 /* check each device to see what state it's in */
1976                 for (extracted = 0, i = 0; i < gcount; i++) {
1977                         if (vd[i] != NULL &&
1978                             vd[i]->vdev_stat.vs_aux != VDEV_AUX_SPLIT_POOL)
1979                                 break;
1980                         ++extracted;
1981                 }
1982         }
1983 
1984         /*
1985          * If every disk has been moved to the new pool, or if we never
1986          * even attempted to look at them, then we split them off for
1987          * good.
1988          */
1989         if (!attempt_reopen || gcount == extracted) {
1990                 for (i = 0; i < gcount; i++)
1991                         if (vd[i] != NULL)
1992                                 vdev_split(vd[i]);
1993                 vdev_reopen(spa->spa_root_vdev);
1994         }
1995 
1996         kmem_free(vd, gcount * sizeof (vdev_t *));
1997 }
1998 
1999 static int
2000 spa_load(spa_t *spa, spa_load_state_t state, spa_import_type_t type,
2001     boolean_t mosconfig)
2002 {
2003         nvlist_t *config = spa->spa_config;
2004         char *ereport = FM_EREPORT_ZFS_POOL;
2005         char *comment;
2006         int error;
2007         uint64_t pool_guid;
2008         nvlist_t *nvl;
2009 
2010         if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID, &pool_guid))
2011                 return (SET_ERROR(EINVAL));
2012 
2013         ASSERT(spa->spa_comment == NULL);
2014         if (nvlist_lookup_string(config, ZPOOL_CONFIG_COMMENT, &comment) == 0)
2015                 spa->spa_comment = spa_strdup(comment);
2016 
2017         /*
2018          * Versioning wasn't explicitly added to the label until later, so if
2019          * it's not present treat it as the initial version.
2020          */
2021         if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_VERSION,
2022             &spa->spa_ubsync.ub_version) != 0)
2023                 spa->spa_ubsync.ub_version = SPA_VERSION_INITIAL;
2024 
2025         (void) nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG,
2026             &spa->spa_config_txg);
2027 
2028         if ((state == SPA_LOAD_IMPORT || state == SPA_LOAD_TRYIMPORT) &&
2029             spa_guid_exists(pool_guid, 0)) {
2030                 error = SET_ERROR(EEXIST);
2031         } else {
2032                 spa->spa_config_guid = pool_guid;
2033 
2034                 if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_SPLIT,
2035                     &nvl) == 0) {
2036                         VERIFY(nvlist_dup(nvl, &spa->spa_config_splitting,
2037                             KM_SLEEP) == 0);
2038                 }
2039 
2040                 nvlist_free(spa->spa_load_info);
2041                 spa->spa_load_info = fnvlist_alloc();
2042 
2043                 gethrestime(&spa->spa_loaded_ts);
2044                 error = spa_load_impl(spa, pool_guid, config, state, type,
2045                     mosconfig, &ereport);
2046         }
2047 
2048         spa->spa_minref = refcount_count(&spa->spa_refcount);
2049         if (error) {
2050                 if (error != EEXIST) {
2051                         spa->spa_loaded_ts.tv_sec = 0;
2052                         spa->spa_loaded_ts.tv_nsec = 0;
2053                 }
2054                 if (error != EBADF) {
2055                         zfs_ereport_post(ereport, spa, NULL, NULL, 0, 0);
2056                 }
2057         }
2058         spa->spa_load_state = error ? SPA_LOAD_ERROR : SPA_LOAD_NONE;
2059         spa->spa_ena = 0;
2060 
2061         return (error);
2062 }
2063 
2064 /*
2065  * Load an existing storage pool, using the pool's builtin spa_config as a
2066  * source of configuration information.
2067  */
2068 static int
2069 spa_load_impl(spa_t *spa, uint64_t pool_guid, nvlist_t *config,
2070     spa_load_state_t state, spa_import_type_t type, boolean_t mosconfig,
2071     char **ereport)
2072 {
2073         int error = 0;
2074         nvlist_t *nvroot = NULL;
2075         nvlist_t *label;
2076         vdev_t *rvd;
2077         uberblock_t *ub = &spa->spa_uberblock;
2078         uint64_t children, config_cache_txg = spa->spa_config_txg;
2079         int orig_mode = spa->spa_mode;
2080         int parse;
2081         uint64_t obj;
2082         boolean_t missing_feat_write = B_FALSE;
2083 
2084         /*
2085          * If this is an untrusted config, access the pool in read-only mode.
2086          * This prevents things like resilvering recently removed devices.
2087          */
2088         if (!mosconfig)
2089                 spa->spa_mode = FREAD;
2090 
2091         ASSERT(MUTEX_HELD(&spa_namespace_lock));
2092 
2093         spa->spa_load_state = state;
2094 
2095         if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nvroot))
2096                 return (SET_ERROR(EINVAL));
2097 
2098         parse = (type == SPA_IMPORT_EXISTING ?
2099             VDEV_ALLOC_LOAD : VDEV_ALLOC_SPLIT);
2100 
2101         /*
2102          * Create "The Godfather" zio to hold all async IOs
2103          */
2104         spa->spa_async_zio_root = zio_root(spa, NULL, NULL,
2105             ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_GODFATHER);
2106 
2107         /*
2108          * Parse the configuration into a vdev tree.  We explicitly set the
2109          * value that will be returned by spa_version() since parsing the
2110          * configuration requires knowing the version number.
2111          */
2112         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2113         error = spa_config_parse(spa, &rvd, nvroot, NULL, 0, parse);
2114         spa_config_exit(spa, SCL_ALL, FTAG);
2115 
2116         if (error != 0)
2117                 return (error);
2118 
2119         ASSERT(spa->spa_root_vdev == rvd);
2120 
2121         if (type != SPA_IMPORT_ASSEMBLE) {
2122                 ASSERT(spa_guid(spa) == pool_guid);
2123         }
2124 
2125         /*
2126          * Try to open all vdevs, loading each label in the process.
2127          */
2128         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2129         error = vdev_open(rvd);
2130         spa_config_exit(spa, SCL_ALL, FTAG);
2131         if (error != 0)
2132                 return (error);
2133 
2134         /*
2135          * We need to validate the vdev labels against the configuration that
2136          * we have in hand, which is dependent on the setting of mosconfig. If
2137          * mosconfig is true then we're validating the vdev labels based on
2138          * that config.  Otherwise, we're validating against the cached config
2139          * (zpool.cache) that was read when we loaded the zfs module, and then
2140          * later we will recursively call spa_load() and validate against
2141          * the vdev config.
2142          *
2143          * If we're assembling a new pool that's been split off from an
2144          * existing pool, the labels haven't yet been updated so we skip
2145          * validation for now.
2146          */
2147         if (type != SPA_IMPORT_ASSEMBLE) {
2148                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2149                 error = vdev_validate(rvd, mosconfig);
2150                 spa_config_exit(spa, SCL_ALL, FTAG);
2151 
2152                 if (error != 0)
2153                         return (error);
2154 
2155                 if (rvd->vdev_state <= VDEV_STATE_CANT_OPEN)
2156                         return (SET_ERROR(ENXIO));
2157         }
2158 
2159         /*
2160          * Find the best uberblock.
2161          */
2162         vdev_uberblock_load(rvd, ub, &label);
2163 
2164         /*
2165          * If we weren't able to find a single valid uberblock, return failure.
2166          */
2167         if (ub->ub_txg == 0) {
2168                 nvlist_free(label);
2169                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, ENXIO));
2170         }
2171 
2172         /*
2173          * If the pool has an unsupported version we can't open it.
2174          */
2175         if (!SPA_VERSION_IS_SUPPORTED(ub->ub_version)) {
2176                 nvlist_free(label);
2177                 return (spa_vdev_err(rvd, VDEV_AUX_VERSION_NEWER, ENOTSUP));
2178         }
2179 
2180         if (ub->ub_version >= SPA_VERSION_FEATURES) {
2181                 nvlist_t *features;
2182 
2183                 /*
2184                  * If we weren't able to find what's necessary for reading the
2185                  * MOS in the label, return failure.
2186                  */
2187                 if (label == NULL || nvlist_lookup_nvlist(label,
2188                     ZPOOL_CONFIG_FEATURES_FOR_READ, &features) != 0) {
2189                         nvlist_free(label);
2190                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA,
2191                             ENXIO));
2192                 }
2193 
2194                 /*
2195                  * Update our in-core representation with the definitive values
2196                  * from the label.
2197                  */
2198                 nvlist_free(spa->spa_label_features);
2199                 VERIFY(nvlist_dup(features, &spa->spa_label_features, 0) == 0);
2200         }
2201 
2202         nvlist_free(label);
2203 
2204         /*
2205          * Look through entries in the label nvlist's features_for_read. If
2206          * there is a feature listed there which we don't understand then we
2207          * cannot open a pool.
2208          */
2209         if (ub->ub_version >= SPA_VERSION_FEATURES) {
2210                 nvlist_t *unsup_feat;
2211 
2212                 VERIFY(nvlist_alloc(&unsup_feat, NV_UNIQUE_NAME, KM_SLEEP) ==
2213                     0);
2214 
2215                 for (nvpair_t *nvp = nvlist_next_nvpair(spa->spa_label_features,
2216                     NULL); nvp != NULL;
2217                     nvp = nvlist_next_nvpair(spa->spa_label_features, nvp)) {
2218                         if (!zfeature_is_supported(nvpair_name(nvp))) {
2219                                 VERIFY(nvlist_add_string(unsup_feat,
2220                                     nvpair_name(nvp), "") == 0);
2221                         }
2222                 }
2223 
2224                 if (!nvlist_empty(unsup_feat)) {
2225                         VERIFY(nvlist_add_nvlist(spa->spa_load_info,
2226                             ZPOOL_CONFIG_UNSUP_FEAT, unsup_feat) == 0);
2227                         nvlist_free(unsup_feat);
2228                         return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT,
2229                             ENOTSUP));
2230                 }
2231 
2232                 nvlist_free(unsup_feat);
2233         }
2234 
2235         /*
2236          * If the vdev guid sum doesn't match the uberblock, we have an
2237          * incomplete configuration.  We first check to see if the pool
2238          * is aware of the complete config (i.e ZPOOL_CONFIG_VDEV_CHILDREN).
2239          * If it is, defer the vdev_guid_sum check till later so we
2240          * can handle missing vdevs.
2241          */
2242         if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_VDEV_CHILDREN,
2243             &children) != 0 && mosconfig && type != SPA_IMPORT_ASSEMBLE &&
2244             rvd->vdev_guid_sum != ub->ub_guid_sum)
2245                 return (spa_vdev_err(rvd, VDEV_AUX_BAD_GUID_SUM, ENXIO));
2246 
2247         if (type != SPA_IMPORT_ASSEMBLE && spa->spa_config_splitting) {
2248                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2249                 spa_try_repair(spa, config);
2250                 spa_config_exit(spa, SCL_ALL, FTAG);
2251                 nvlist_free(spa->spa_config_splitting);
2252                 spa->spa_config_splitting = NULL;
2253         }
2254 
2255         /*
2256          * Initialize internal SPA structures.
2257          */
2258         spa->spa_state = POOL_STATE_ACTIVE;
2259         spa->spa_ubsync = spa->spa_uberblock;
2260         spa->spa_verify_min_txg = spa->spa_extreme_rewind ?
2261             TXG_INITIAL - 1 : spa_last_synced_txg(spa) - TXG_DEFER_SIZE - 1;
2262         spa->spa_first_txg = spa->spa_last_ubsync_txg ?
2263             spa->spa_last_ubsync_txg : spa_last_synced_txg(spa) + 1;
2264         spa->spa_claim_max_txg = spa->spa_first_txg;
2265         spa->spa_prev_software_version = ub->ub_software_version;
2266 
2267         error = dsl_pool_init(spa, spa->spa_first_txg, &spa->spa_dsl_pool);
2268         if (error)
2269                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2270         spa->spa_meta_objset = spa->spa_dsl_pool->dp_meta_objset;
2271 
2272         if (spa_dir_prop(spa, DMU_POOL_CONFIG, &spa->spa_config_object) != 0)
2273                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2274 
2275         if (spa_version(spa) >= SPA_VERSION_FEATURES) {
2276                 boolean_t missing_feat_read = B_FALSE;
2277                 nvlist_t *unsup_feat, *enabled_feat;
2278 
2279                 if (spa_dir_prop(spa, DMU_POOL_FEATURES_FOR_READ,
2280                     &spa->spa_feat_for_read_obj) != 0) {
2281                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2282                 }
2283 
2284                 if (spa_dir_prop(spa, DMU_POOL_FEATURES_FOR_WRITE,
2285                     &spa->spa_feat_for_write_obj) != 0) {
2286                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2287                 }
2288 
2289                 if (spa_dir_prop(spa, DMU_POOL_FEATURE_DESCRIPTIONS,
2290                     &spa->spa_feat_desc_obj) != 0) {
2291                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2292                 }
2293 
2294                 enabled_feat = fnvlist_alloc();
2295                 unsup_feat = fnvlist_alloc();
2296 
2297                 if (!feature_is_supported(spa->spa_meta_objset,
2298                     spa->spa_feat_for_read_obj, spa->spa_feat_desc_obj,
2299                     unsup_feat, enabled_feat))
2300                         missing_feat_read = B_TRUE;
2301 
2302                 if (spa_writeable(spa) || state == SPA_LOAD_TRYIMPORT) {
2303                         if (!feature_is_supported(spa->spa_meta_objset,
2304                             spa->spa_feat_for_write_obj, spa->spa_feat_desc_obj,
2305                             unsup_feat, enabled_feat)) {
2306                                 missing_feat_write = B_TRUE;
2307                         }
2308                 }
2309 
2310                 fnvlist_add_nvlist(spa->spa_load_info,
2311                     ZPOOL_CONFIG_ENABLED_FEAT, enabled_feat);
2312 
2313                 if (!nvlist_empty(unsup_feat)) {
2314                         fnvlist_add_nvlist(spa->spa_load_info,
2315                             ZPOOL_CONFIG_UNSUP_FEAT, unsup_feat);
2316                 }
2317 
2318                 fnvlist_free(enabled_feat);
2319                 fnvlist_free(unsup_feat);
2320 
2321                 if (!missing_feat_read) {
2322                         fnvlist_add_boolean(spa->spa_load_info,
2323                             ZPOOL_CONFIG_CAN_RDONLY);
2324                 }
2325 
2326                 /*
2327                  * If the state is SPA_LOAD_TRYIMPORT, our objective is
2328                  * twofold: to determine whether the pool is available for
2329                  * import in read-write mode and (if it is not) whether the
2330                  * pool is available for import in read-only mode. If the pool
2331                  * is available for import in read-write mode, it is displayed
2332                  * as available in userland; if it is not available for import
2333                  * in read-only mode, it is displayed as unavailable in
2334                  * userland. If the pool is available for import in read-only
2335                  * mode but not read-write mode, it is displayed as unavailable
2336                  * in userland with a special note that the pool is actually
2337                  * available for open in read-only mode.
2338                  *
2339                  * As a result, if the state is SPA_LOAD_TRYIMPORT and we are
2340                  * missing a feature for write, we must first determine whether
2341                  * the pool can be opened read-only before returning to
2342                  * userland in order to know whether to display the
2343                  * abovementioned note.
2344                  */
2345                 if (missing_feat_read || (missing_feat_write &&
2346                     spa_writeable(spa))) {
2347                         return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT,
2348                             ENOTSUP));
2349                 }
2350         }
2351 
2352         spa->spa_is_initializing = B_TRUE;
2353         error = dsl_pool_open(spa->spa_dsl_pool);
2354         spa->spa_is_initializing = B_FALSE;
2355         if (error != 0)
2356                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2357 
2358         if (!mosconfig) {
2359                 uint64_t hostid;
2360                 nvlist_t *policy = NULL, *nvconfig;
2361 
2362                 if (load_nvlist(spa, spa->spa_config_object, &nvconfig) != 0)
2363                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2364 
2365                 if (!spa_is_root(spa) && nvlist_lookup_uint64(nvconfig,
2366                     ZPOOL_CONFIG_HOSTID, &hostid) == 0) {
2367                         char *hostname;
2368                         unsigned long myhostid = 0;
2369 
2370                         VERIFY(nvlist_lookup_string(nvconfig,
2371                             ZPOOL_CONFIG_HOSTNAME, &hostname) == 0);
2372 
2373 #ifdef  _KERNEL
2374                         myhostid = zone_get_hostid(NULL);
2375 #else   /* _KERNEL */
2376                         /*
2377                          * We're emulating the system's hostid in userland, so
2378                          * we can't use zone_get_hostid().
2379                          */
2380                         (void) ddi_strtoul(hw_serial, NULL, 10, &myhostid);
2381 #endif  /* _KERNEL */
2382                         if (hostid != 0 && myhostid != 0 &&
2383                             hostid != myhostid) {
2384                                 nvlist_free(nvconfig);
2385                                 cmn_err(CE_WARN, "pool '%s' could not be "
2386                                     "loaded as it was last accessed by "
2387                                     "another system (host: %s hostid: 0x%lx). "
2388                                     "See: http://illumos.org/msg/ZFS-8000-EY",
2389                                     spa_name(spa), hostname,
2390                                     (unsigned long)hostid);
2391                                 return (SET_ERROR(EBADF));
2392                         }
2393                 }
2394                 if (nvlist_lookup_nvlist(spa->spa_config,
2395                     ZPOOL_REWIND_POLICY, &policy) == 0)
2396                         VERIFY(nvlist_add_nvlist(nvconfig,
2397                             ZPOOL_REWIND_POLICY, policy) == 0);
2398 
2399                 spa_config_set(spa, nvconfig);
2400                 spa_unload(spa);
2401                 spa_deactivate(spa);
2402                 spa_activate(spa, orig_mode);
2403 
2404                 return (spa_load(spa, state, SPA_IMPORT_EXISTING, B_TRUE));
2405         }
2406 
2407         if (spa_dir_prop(spa, DMU_POOL_SYNC_BPOBJ, &obj) != 0)
2408                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2409         error = bpobj_open(&spa->spa_deferred_bpobj, spa->spa_meta_objset, obj);
2410         if (error != 0)
2411                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2412 
2413         /*
2414          * Load the bit that tells us to use the new accounting function
2415          * (raid-z deflation).  If we have an older pool, this will not
2416          * be present.
2417          */
2418         error = spa_dir_prop(spa, DMU_POOL_DEFLATE, &spa->spa_deflate);
2419         if (error != 0 && error != ENOENT)
2420                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2421 
2422         error = spa_dir_prop(spa, DMU_POOL_CREATION_VERSION,
2423             &spa->spa_creation_version);
2424         if (error != 0 && error != ENOENT)
2425                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2426 
2427         /*
2428          * Load the persistent error log.  If we have an older pool, this will
2429          * not be present.
2430          */
2431         error = spa_dir_prop(spa, DMU_POOL_ERRLOG_LAST, &spa->spa_errlog_last);
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_ERRLOG_SCRUB,
2436             &spa->spa_errlog_scrub);
2437         if (error != 0 && error != ENOENT)
2438                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2439 
2440         /*
2441          * Load the history object.  If we have an older pool, this
2442          * will not be present.
2443          */
2444         error = spa_dir_prop(spa, DMU_POOL_HISTORY, &spa->spa_history);
2445         if (error != 0 && error != ENOENT)
2446                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2447 
2448         /*
2449          * If we're assembling the pool from the split-off vdevs of
2450          * an existing pool, we don't want to attach the spares & cache
2451          * devices.
2452          */
2453 
2454         /*
2455          * Load any hot spares for this pool.
2456          */
2457         error = spa_dir_prop(spa, DMU_POOL_SPARES, &spa->spa_spares.sav_object);
2458         if (error != 0 && error != ENOENT)
2459                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2460         if (error == 0 && type != SPA_IMPORT_ASSEMBLE) {
2461                 ASSERT(spa_version(spa) >= SPA_VERSION_SPARES);
2462                 if (load_nvlist(spa, spa->spa_spares.sav_object,
2463                     &spa->spa_spares.sav_config) != 0)
2464                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2465 
2466                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2467                 spa_load_spares(spa);
2468                 spa_config_exit(spa, SCL_ALL, FTAG);
2469         } else if (error == 0) {
2470                 spa->spa_spares.sav_sync = B_TRUE;
2471         }
2472 
2473         /*
2474          * Load any level 2 ARC devices for this pool.
2475          */
2476         error = spa_dir_prop(spa, DMU_POOL_L2CACHE,
2477             &spa->spa_l2cache.sav_object);
2478         if (error != 0 && error != ENOENT)
2479                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2480         if (error == 0 && type != SPA_IMPORT_ASSEMBLE) {
2481                 ASSERT(spa_version(spa) >= SPA_VERSION_L2CACHE);
2482                 if (load_nvlist(spa, spa->spa_l2cache.sav_object,
2483                     &spa->spa_l2cache.sav_config) != 0)
2484                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2485 
2486                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2487                 spa_load_l2cache(spa);
2488                 spa_config_exit(spa, SCL_ALL, FTAG);
2489         } else if (error == 0) {
2490                 spa->spa_l2cache.sav_sync = B_TRUE;
2491         }
2492 
2493         spa->spa_delegation = zpool_prop_default_numeric(ZPOOL_PROP_DELEGATION);
2494 
2495         error = spa_dir_prop(spa, DMU_POOL_PROPS, &spa->spa_pool_props_object);
2496         if (error && error != ENOENT)
2497                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2498 
2499         if (error == 0) {
2500                 uint64_t autoreplace;
2501 
2502                 spa_prop_find(spa, ZPOOL_PROP_BOOTFS, &spa->spa_bootfs);
2503                 spa_prop_find(spa, ZPOOL_PROP_AUTOREPLACE, &autoreplace);
2504                 spa_prop_find(spa, ZPOOL_PROP_DELEGATION, &spa->spa_delegation);
2505                 spa_prop_find(spa, ZPOOL_PROP_FAILUREMODE, &spa->spa_failmode);
2506                 spa_prop_find(spa, ZPOOL_PROP_AUTOEXPAND, &spa->spa_autoexpand);
2507                 spa_prop_find(spa, ZPOOL_PROP_DEDUPDITTO,
2508                     &spa->spa_dedup_ditto);
2509 
2510                 spa->spa_autoreplace = (autoreplace != 0);
2511         }
2512 
2513         /*
2514          * If the 'autoreplace' property is set, then post a resource notifying
2515          * the ZFS DE that it should not issue any faults for unopenable
2516          * devices.  We also iterate over the vdevs, and post a sysevent for any
2517          * unopenable vdevs so that the normal autoreplace handler can take
2518          * over.
2519          */
2520         if (spa->spa_autoreplace && state != SPA_LOAD_TRYIMPORT) {
2521                 spa_check_removed(spa->spa_root_vdev);
2522                 /*
2523                  * For the import case, this is done in spa_import(), because
2524                  * at this point we're using the spare definitions from
2525                  * the MOS config, not necessarily from the userland config.
2526                  */
2527                 if (state != SPA_LOAD_IMPORT) {
2528                         spa_aux_check_removed(&spa->spa_spares);
2529                         spa_aux_check_removed(&spa->spa_l2cache);
2530                 }
2531         }
2532 
2533         /*
2534          * Load the vdev state for all toplevel vdevs.
2535          */
2536         vdev_load(rvd);
2537 
2538         /*
2539          * Propagate the leaf DTLs we just loaded all the way up the tree.
2540          */
2541         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2542         vdev_dtl_reassess(rvd, 0, 0, B_FALSE);
2543         spa_config_exit(spa, SCL_ALL, FTAG);
2544 
2545         /*
2546          * Load the DDTs (dedup tables).
2547          */
2548         error = ddt_load(spa);
2549         if (error != 0)
2550                 return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2551 
2552         spa_update_dspace(spa);
2553 
2554         /*
2555          * Validate the config, using the MOS config to fill in any
2556          * information which might be missing.  If we fail to validate
2557          * the config then declare the pool unfit for use. If we're
2558          * assembling a pool from a split, the log is not transferred
2559          * over.
2560          */
2561         if (type != SPA_IMPORT_ASSEMBLE) {
2562                 nvlist_t *nvconfig;
2563 
2564                 if (load_nvlist(spa, spa->spa_config_object, &nvconfig) != 0)
2565                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2566 
2567                 if (!spa_config_valid(spa, nvconfig)) {
2568                         nvlist_free(nvconfig);
2569                         return (spa_vdev_err(rvd, VDEV_AUX_BAD_GUID_SUM,
2570                             ENXIO));
2571                 }
2572                 nvlist_free(nvconfig);
2573 
2574                 /*
2575                  * Now that we've validated the config, check the state of the
2576                  * root vdev.  If it can't be opened, it indicates one or
2577                  * more toplevel vdevs are faulted.
2578                  */
2579                 if (rvd->vdev_state <= VDEV_STATE_CANT_OPEN)
2580                         return (SET_ERROR(ENXIO));
2581 
2582                 if (spa_check_logs(spa)) {
2583                         *ereport = FM_EREPORT_ZFS_LOG_REPLAY;
2584                         return (spa_vdev_err(rvd, VDEV_AUX_BAD_LOG, ENXIO));
2585                 }
2586         }
2587 
2588         if (missing_feat_write) {
2589                 ASSERT(state == SPA_LOAD_TRYIMPORT);
2590 
2591                 /*
2592                  * At this point, we know that we can open the pool in
2593                  * read-only mode but not read-write mode. We now have enough
2594                  * information and can return to userland.
2595                  */
2596                 return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT, ENOTSUP));
2597         }
2598 
2599         /*
2600          * We've successfully opened the pool, verify that we're ready
2601          * to start pushing transactions.
2602          */
2603         if (state != SPA_LOAD_TRYIMPORT) {
2604                 if (error = spa_load_verify(spa))
2605                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA,
2606                             error));
2607         }
2608 
2609         if (spa_writeable(spa) && (state == SPA_LOAD_RECOVER ||
2610             spa->spa_load_max_txg == UINT64_MAX)) {
2611                 dmu_tx_t *tx;
2612                 int need_update = B_FALSE;
2613 
2614                 ASSERT(state != SPA_LOAD_TRYIMPORT);
2615 
2616                 /*
2617                  * Claim log blocks that haven't been committed yet.
2618                  * This must all happen in a single txg.
2619                  * Note: spa_claim_max_txg is updated by spa_claim_notify(),
2620                  * invoked from zil_claim_log_block()'s i/o done callback.
2621                  * Price of rollback is that we abandon the log.
2622                  */
2623                 spa->spa_claiming = B_TRUE;
2624 
2625                 tx = dmu_tx_create_assigned(spa_get_dsl(spa),
2626                     spa_first_txg(spa));
2627                 (void) dmu_objset_find(spa_name(spa),
2628                     zil_claim, tx, DS_FIND_CHILDREN);
2629                 dmu_tx_commit(tx);
2630 
2631                 spa->spa_claiming = B_FALSE;
2632 
2633                 spa_set_log_state(spa, SPA_LOG_GOOD);
2634                 spa->spa_sync_on = B_TRUE;
2635                 txg_sync_start(spa->spa_dsl_pool);
2636 
2637                 /*
2638                  * Wait for all claims to sync.  We sync up to the highest
2639                  * claimed log block birth time so that claimed log blocks
2640                  * don't appear to be from the future.  spa_claim_max_txg
2641                  * will have been set for us by either zil_check_log_chain()
2642                  * (invoked from spa_check_logs()) or zil_claim() above.
2643                  */
2644                 txg_wait_synced(spa->spa_dsl_pool, spa->spa_claim_max_txg);
2645 
2646                 /*
2647                  * If the config cache is stale, or we have uninitialized
2648                  * metaslabs (see spa_vdev_add()), then update the config.
2649                  *
2650                  * If this is a verbatim import, trust the current
2651                  * in-core spa_config and update the disk labels.
2652                  */
2653                 if (config_cache_txg != spa->spa_config_txg ||
2654                     state == SPA_LOAD_IMPORT ||
2655                     state == SPA_LOAD_RECOVER ||
2656                     (spa->spa_import_flags & ZFS_IMPORT_VERBATIM))
2657                         need_update = B_TRUE;
2658 
2659                 for (int c = 0; c < rvd->vdev_children; c++)
2660                         if (rvd->vdev_child[c]->vdev_ms_array == 0)
2661                                 need_update = B_TRUE;
2662 
2663                 /*
2664                  * Update the config cache asychronously in case we're the
2665                  * root pool, in which case the config cache isn't writable yet.
2666                  */
2667                 if (need_update)
2668                         spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
2669 
2670                 /*
2671                  * Check all DTLs to see if anything needs resilvering.
2672                  */
2673                 if (!dsl_scan_resilvering(spa->spa_dsl_pool) &&
2674                     vdev_resilver_needed(rvd, NULL, NULL))
2675                         spa_async_request(spa, SPA_ASYNC_RESILVER);
2676 
2677                 /*
2678                  * Log the fact that we booted up (so that we can detect if
2679                  * we rebooted in the middle of an operation).
2680                  */
2681                 spa_history_log_version(spa, "open");
2682 
2683                 /*
2684                  * Delete any inconsistent datasets.
2685                  */
2686                 (void) dmu_objset_find(spa_name(spa),
2687                     dsl_destroy_inconsistent, NULL, DS_FIND_CHILDREN);
2688 
2689                 /*
2690                  * Clean up any stale temporary dataset userrefs.
2691                  */
2692                 dsl_pool_clean_tmp_userrefs(spa->spa_dsl_pool);
2693         }
2694 
2695         return (0);
2696 }
2697 
2698 static int
2699 spa_load_retry(spa_t *spa, spa_load_state_t state, int mosconfig)
2700 {
2701         int mode = spa->spa_mode;
2702 
2703         spa_unload(spa);
2704         spa_deactivate(spa);
2705 
2706         spa->spa_load_max_txg--;
2707 
2708         spa_activate(spa, mode);
2709         spa_async_suspend(spa);
2710 
2711         return (spa_load(spa, state, SPA_IMPORT_EXISTING, mosconfig));
2712 }
2713 
2714 /*
2715  * If spa_load() fails this function will try loading prior txg's. If
2716  * 'state' is SPA_LOAD_RECOVER and one of these loads succeeds the pool
2717  * will be rewound to that txg. If 'state' is not SPA_LOAD_RECOVER this
2718  * function will not rewind the pool and will return the same error as
2719  * spa_load().
2720  */
2721 static int
2722 spa_load_best(spa_t *spa, spa_load_state_t state, int mosconfig,
2723     uint64_t max_request, int rewind_flags)
2724 {
2725         nvlist_t *loadinfo = NULL;
2726         nvlist_t *config = NULL;
2727         int load_error, rewind_error;
2728         uint64_t safe_rewind_txg;
2729         uint64_t min_txg;
2730 
2731         if (spa->spa_load_txg && state == SPA_LOAD_RECOVER) {
2732                 spa->spa_load_max_txg = spa->spa_load_txg;
2733                 spa_set_log_state(spa, SPA_LOG_CLEAR);
2734         } else {
2735                 spa->spa_load_max_txg = max_request;
2736         }
2737 
2738         load_error = rewind_error = spa_load(spa, state, SPA_IMPORT_EXISTING,
2739             mosconfig);
2740         if (load_error == 0)
2741                 return (0);
2742 
2743         if (spa->spa_root_vdev != NULL)
2744                 config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
2745 
2746         spa->spa_last_ubsync_txg = spa->spa_uberblock.ub_txg;
2747         spa->spa_last_ubsync_txg_ts = spa->spa_uberblock.ub_timestamp;
2748 
2749         if (rewind_flags & ZPOOL_NEVER_REWIND) {
2750                 nvlist_free(config);
2751                 return (load_error);
2752         }
2753 
2754         if (state == SPA_LOAD_RECOVER) {
2755                 /* Price of rolling back is discarding txgs, including log */
2756                 spa_set_log_state(spa, SPA_LOG_CLEAR);
2757         } else {
2758                 /*
2759                  * If we aren't rolling back save the load info from our first
2760                  * import attempt so that we can restore it after attempting
2761                  * to rewind.
2762                  */
2763                 loadinfo = spa->spa_load_info;
2764                 spa->spa_load_info = fnvlist_alloc();
2765         }
2766 
2767         spa->spa_load_max_txg = spa->spa_last_ubsync_txg;
2768         safe_rewind_txg = spa->spa_last_ubsync_txg - TXG_DEFER_SIZE;
2769         min_txg = (rewind_flags & ZPOOL_EXTREME_REWIND) ?
2770             TXG_INITIAL : safe_rewind_txg;
2771 
2772         /*
2773          * Continue as long as we're finding errors, we're still within
2774          * the acceptable rewind range, and we're still finding uberblocks
2775          */
2776         while (rewind_error && spa->spa_uberblock.ub_txg >= min_txg &&
2777             spa->spa_uberblock.ub_txg <= spa->spa_load_max_txg) {
2778                 if (spa->spa_load_max_txg < safe_rewind_txg)
2779                         spa->spa_extreme_rewind = B_TRUE;
2780                 rewind_error = spa_load_retry(spa, state, mosconfig);
2781         }
2782 
2783         spa->spa_extreme_rewind = B_FALSE;
2784         spa->spa_load_max_txg = UINT64_MAX;
2785 
2786         if (config && (rewind_error || state != SPA_LOAD_RECOVER))
2787                 spa_config_set(spa, config);
2788 
2789         if (state == SPA_LOAD_RECOVER) {
2790                 ASSERT3P(loadinfo, ==, NULL);
2791                 return (rewind_error);
2792         } else {
2793                 /* Store the rewind info as part of the initial load info */
2794                 fnvlist_add_nvlist(loadinfo, ZPOOL_CONFIG_REWIND_INFO,
2795                     spa->spa_load_info);
2796 
2797                 /* Restore the initial load info */
2798                 fnvlist_free(spa->spa_load_info);
2799                 spa->spa_load_info = loadinfo;
2800 
2801                 return (load_error);
2802         }
2803 }
2804 
2805 /*
2806  * Pool Open/Import
2807  *
2808  * The import case is identical to an open except that the configuration is sent
2809  * down from userland, instead of grabbed from the configuration cache.  For the
2810  * case of an open, the pool configuration will exist in the
2811  * POOL_STATE_UNINITIALIZED state.
2812  *
2813  * The stats information (gen/count/ustats) is used to gather vdev statistics at
2814  * the same time open the pool, without having to keep around the spa_t in some
2815  * ambiguous state.
2816  */
2817 static int
2818 spa_open_common(const char *pool, spa_t **spapp, void *tag, nvlist_t *nvpolicy,
2819     nvlist_t **config)
2820 {
2821         spa_t *spa;
2822         spa_load_state_t state = SPA_LOAD_OPEN;
2823         int error;
2824         int locked = B_FALSE;
2825 
2826         *spapp = NULL;
2827 
2828         /*
2829          * As disgusting as this is, we need to support recursive calls to this
2830          * function because dsl_dir_open() is called during spa_load(), and ends
2831          * up calling spa_open() again.  The real fix is to figure out how to
2832          * avoid dsl_dir_open() calling this in the first place.
2833          */
2834         if (mutex_owner(&spa_namespace_lock) != curthread) {
2835                 mutex_enter(&spa_namespace_lock);
2836                 locked = B_TRUE;
2837         }
2838 
2839         if ((spa = spa_lookup(pool)) == NULL) {
2840                 if (locked)
2841                         mutex_exit(&spa_namespace_lock);
2842                 return (SET_ERROR(ENOENT));
2843         }
2844 
2845         if (spa->spa_state == POOL_STATE_UNINITIALIZED) {
2846                 zpool_rewind_policy_t policy;
2847 
2848                 zpool_get_rewind_policy(nvpolicy ? nvpolicy : spa->spa_config,
2849                     &policy);
2850                 if (policy.zrp_request & ZPOOL_DO_REWIND)
2851                         state = SPA_LOAD_RECOVER;
2852 
2853                 spa_activate(spa, spa_mode_global);
2854 
2855                 if (state != SPA_LOAD_RECOVER)
2856                         spa->spa_last_ubsync_txg = spa->spa_load_txg = 0;
2857 
2858                 error = spa_load_best(spa, state, B_FALSE, policy.zrp_txg,
2859                     policy.zrp_request);
2860 
2861                 if (error == EBADF) {
2862                         /*
2863                          * If vdev_validate() returns failure (indicated by
2864                          * EBADF), it indicates that one of the vdevs indicates
2865                          * that the pool has been exported or destroyed.  If
2866                          * this is the case, the config cache is out of sync and
2867                          * we should remove the pool from the namespace.
2868                          */
2869                         spa_unload(spa);
2870                         spa_deactivate(spa);
2871                         spa_config_sync(spa, B_TRUE, B_TRUE);
2872                         spa_remove(spa);
2873                         if (locked)
2874                                 mutex_exit(&spa_namespace_lock);
2875                         return (SET_ERROR(ENOENT));
2876                 }
2877 
2878                 if (error) {
2879                         /*
2880                          * We can't open the pool, but we still have useful
2881                          * information: the state of each vdev after the
2882                          * attempted vdev_open().  Return this to the user.
2883                          */
2884                         if (config != NULL && spa->spa_config) {
2885                                 VERIFY(nvlist_dup(spa->spa_config, config,
2886                                     KM_SLEEP) == 0);
2887                                 VERIFY(nvlist_add_nvlist(*config,
2888                                     ZPOOL_CONFIG_LOAD_INFO,
2889                                     spa->spa_load_info) == 0);
2890                         }
2891                         spa_unload(spa);
2892                         spa_deactivate(spa);
2893                         spa->spa_last_open_failed = error;
2894                         if (locked)
2895                                 mutex_exit(&spa_namespace_lock);
2896                         *spapp = NULL;
2897                         return (error);
2898                 }
2899         }
2900 
2901         spa_open_ref(spa, tag);
2902 
2903         if (config != NULL)
2904                 *config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
2905 
2906         /*
2907          * If we've recovered the pool, pass back any information we
2908          * gathered while doing the load.
2909          */
2910         if (state == SPA_LOAD_RECOVER) {
2911                 VERIFY(nvlist_add_nvlist(*config, ZPOOL_CONFIG_LOAD_INFO,
2912                     spa->spa_load_info) == 0);
2913         }
2914 
2915         if (locked) {
2916                 spa->spa_last_open_failed = 0;
2917                 spa->spa_last_ubsync_txg = 0;
2918                 spa->spa_load_txg = 0;
2919                 mutex_exit(&spa_namespace_lock);
2920         }
2921 
2922         *spapp = spa;
2923 
2924         return (0);
2925 }
2926 
2927 int
2928 spa_open_rewind(const char *name, spa_t **spapp, void *tag, nvlist_t *policy,
2929     nvlist_t **config)
2930 {
2931         return (spa_open_common(name, spapp, tag, policy, config));
2932 }
2933 
2934 int
2935 spa_open(const char *name, spa_t **spapp, void *tag)
2936 {
2937         return (spa_open_common(name, spapp, tag, NULL, NULL));
2938 }
2939 
2940 /*
2941  * Lookup the given spa_t, incrementing the inject count in the process,
2942  * preventing it from being exported or destroyed.
2943  */
2944 spa_t *
2945 spa_inject_addref(char *name)
2946 {
2947         spa_t *spa;
2948 
2949         mutex_enter(&spa_namespace_lock);
2950         if ((spa = spa_lookup(name)) == NULL) {
2951                 mutex_exit(&spa_namespace_lock);
2952                 return (NULL);
2953         }
2954         spa->spa_inject_ref++;
2955         mutex_exit(&spa_namespace_lock);
2956 
2957         return (spa);
2958 }
2959 
2960 void
2961 spa_inject_delref(spa_t *spa)
2962 {
2963         mutex_enter(&spa_namespace_lock);
2964         spa->spa_inject_ref--;
2965         mutex_exit(&spa_namespace_lock);
2966 }
2967 
2968 /*
2969  * Add spares device information to the nvlist.
2970  */
2971 static void
2972 spa_add_spares(spa_t *spa, nvlist_t *config)
2973 {
2974         nvlist_t **spares;
2975         uint_t i, nspares;
2976         nvlist_t *nvroot;
2977         uint64_t guid;
2978         vdev_stat_t *vs;
2979         uint_t vsc;
2980         uint64_t pool;
2981 
2982         ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
2983 
2984         if (spa->spa_spares.sav_count == 0)
2985                 return;
2986 
2987         VERIFY(nvlist_lookup_nvlist(config,
2988             ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0);
2989         VERIFY(nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
2990             ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
2991         if (nspares != 0) {
2992                 VERIFY(nvlist_add_nvlist_array(nvroot,
2993                     ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
2994                 VERIFY(nvlist_lookup_nvlist_array(nvroot,
2995                     ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
2996 
2997                 /*
2998                  * Go through and find any spares which have since been
2999                  * repurposed as an active spare.  If this is the case, update
3000                  * their status appropriately.
3001                  */
3002                 for (i = 0; i < nspares; i++) {
3003                         VERIFY(nvlist_lookup_uint64(spares[i],
3004                             ZPOOL_CONFIG_GUID, &guid) == 0);
3005                         if (spa_spare_exists(guid, &pool, NULL) &&
3006                             pool != 0ULL) {
3007                                 VERIFY(nvlist_lookup_uint64_array(
3008                                     spares[i], ZPOOL_CONFIG_VDEV_STATS,
3009                                     (uint64_t **)&vs, &vsc) == 0);
3010                                 vs->vs_state = VDEV_STATE_CANT_OPEN;
3011                                 vs->vs_aux = VDEV_AUX_SPARED;
3012                         }
3013                 }
3014         }
3015 }
3016 
3017 /*
3018  * Add l2cache device information to the nvlist, including vdev stats.
3019  */
3020 static void
3021 spa_add_l2cache(spa_t *spa, nvlist_t *config)
3022 {
3023         nvlist_t **l2cache;
3024         uint_t i, j, nl2cache;
3025         nvlist_t *nvroot;
3026         uint64_t guid;
3027         vdev_t *vd;
3028         vdev_stat_t *vs;
3029         uint_t vsc;
3030 
3031         ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
3032 
3033         if (spa->spa_l2cache.sav_count == 0)
3034                 return;
3035 
3036         VERIFY(nvlist_lookup_nvlist(config,
3037             ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0);
3038         VERIFY(nvlist_lookup_nvlist_array(spa->spa_l2cache.sav_config,
3039             ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
3040         if (nl2cache != 0) {
3041                 VERIFY(nvlist_add_nvlist_array(nvroot,
3042                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
3043                 VERIFY(nvlist_lookup_nvlist_array(nvroot,
3044                     ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
3045 
3046                 /*
3047                  * Update level 2 cache device stats.
3048                  */
3049 
3050                 for (i = 0; i < nl2cache; i++) {
3051                         VERIFY(nvlist_lookup_uint64(l2cache[i],
3052                             ZPOOL_CONFIG_GUID, &guid) == 0);
3053 
3054                         vd = NULL;
3055                         for (j = 0; j < spa->spa_l2cache.sav_count; j++) {
3056                                 if (guid ==
3057                                     spa->spa_l2cache.sav_vdevs[j]->vdev_guid) {
3058                                         vd = spa->spa_l2cache.sav_vdevs[j];
3059                                         break;
3060                                 }
3061                         }
3062                         ASSERT(vd != NULL);
3063 
3064                         VERIFY(nvlist_lookup_uint64_array(l2cache[i],
3065                             ZPOOL_CONFIG_VDEV_STATS, (uint64_t **)&vs, &vsc)
3066                             == 0);
3067                         vdev_get_stats(vd, vs);
3068                 }
3069         }
3070 }
3071 
3072 static void
3073 spa_add_feature_stats(spa_t *spa, nvlist_t *config)
3074 {
3075         nvlist_t *features;
3076         zap_cursor_t zc;
3077         zap_attribute_t za;
3078 
3079         ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
3080         VERIFY(nvlist_alloc(&features, NV_UNIQUE_NAME, KM_SLEEP) == 0);
3081 
3082         if (spa->spa_feat_for_read_obj != 0) {
3083                 for (zap_cursor_init(&zc, spa->spa_meta_objset,
3084                     spa->spa_feat_for_read_obj);
3085                     zap_cursor_retrieve(&zc, &za) == 0;
3086                     zap_cursor_advance(&zc)) {
3087                         ASSERT(za.za_integer_length == sizeof (uint64_t) &&
3088                             za.za_num_integers == 1);
3089                         VERIFY3U(0, ==, nvlist_add_uint64(features, za.za_name,
3090                             za.za_first_integer));
3091                 }
3092                 zap_cursor_fini(&zc);
3093         }
3094 
3095         if (spa->spa_feat_for_write_obj != 0) {
3096                 for (zap_cursor_init(&zc, spa->spa_meta_objset,
3097                     spa->spa_feat_for_write_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         VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_FEATURE_STATS,
3109             features) == 0);
3110         nvlist_free(features);
3111 }
3112 
3113 int
3114 spa_get_stats(const char *name, nvlist_t **config,
3115     char *altroot, size_t buflen)
3116 {
3117         int error;
3118         spa_t *spa;
3119 
3120         *config = NULL;
3121         error = spa_open_common(name, &spa, FTAG, NULL, config);
3122 
3123         if (spa != NULL) {
3124                 /*
3125                  * This still leaves a window of inconsistency where the spares
3126                  * or l2cache devices could change and the config would be
3127                  * self-inconsistent.
3128                  */
3129                 spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
3130 
3131                 if (*config != NULL) {
3132                         uint64_t loadtimes[2];
3133 
3134                         loadtimes[0] = spa->spa_loaded_ts.tv_sec;
3135                         loadtimes[1] = spa->spa_loaded_ts.tv_nsec;
3136                         VERIFY(nvlist_add_uint64_array(*config,
3137                             ZPOOL_CONFIG_LOADED_TIME, loadtimes, 2) == 0);
3138 
3139                         VERIFY(nvlist_add_uint64(*config,
3140                             ZPOOL_CONFIG_ERRCOUNT,
3141                             spa_get_errlog_size(spa)) == 0);
3142 
3143                         if (spa_suspended(spa))
3144                                 VERIFY(nvlist_add_uint64(*config,
3145                                     ZPOOL_CONFIG_SUSPENDED,
3146                                     spa->spa_failmode) == 0);
3147 
3148                         spa_add_spares(spa, *config);
3149                         spa_add_l2cache(spa, *config);
3150                         spa_add_feature_stats(spa, *config);
3151                 }
3152         }
3153 
3154         /*
3155          * We want to get the alternate root even for faulted pools, so we cheat
3156          * and call spa_lookup() directly.
3157          */
3158         if (altroot) {
3159                 if (spa == NULL) {
3160                         mutex_enter(&spa_namespace_lock);
3161                         spa = spa_lookup(name);
3162                         if (spa)
3163                                 spa_altroot(spa, altroot, buflen);
3164                         else
3165                                 altroot[0] = '\0';
3166                         spa = NULL;
3167                         mutex_exit(&spa_namespace_lock);
3168                 } else {
3169                         spa_altroot(spa, altroot, buflen);
3170                 }
3171         }
3172 
3173         if (spa != NULL) {
3174                 spa_config_exit(spa, SCL_CONFIG, FTAG);
3175                 spa_close(spa, FTAG);
3176         }
3177 
3178         return (error);
3179 }
3180 
3181 /*
3182  * Validate that the auxiliary device array is well formed.  We must have an
3183  * array of nvlists, each which describes a valid leaf vdev.  If this is an
3184  * import (mode is VDEV_ALLOC_SPARE), then we allow corrupted spares to be
3185  * specified, as long as they are well-formed.
3186  */
3187 static int
3188 spa_validate_aux_devs(spa_t *spa, nvlist_t *nvroot, uint64_t crtxg, int mode,
3189     spa_aux_vdev_t *sav, const char *config, uint64_t version,
3190     vdev_labeltype_t label)
3191 {
3192         nvlist_t **dev;
3193         uint_t i, ndev;
3194         vdev_t *vd;
3195         int error;
3196 
3197         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
3198 
3199         /*
3200          * It's acceptable to have no devs specified.
3201          */
3202         if (nvlist_lookup_nvlist_array(nvroot, config, &dev, &ndev) != 0)
3203                 return (0);
3204 
3205         if (ndev == 0)
3206                 return (SET_ERROR(EINVAL));
3207 
3208         /*
3209          * Make sure the pool is formatted with a version that supports this
3210          * device type.
3211          */
3212         if (spa_version(spa) < version)
3213                 return (SET_ERROR(ENOTSUP));
3214 
3215         /*
3216          * Set the pending device list so we correctly handle device in-use
3217          * checking.
3218          */
3219         sav->sav_pending = dev;
3220         sav->sav_npending = ndev;
3221 
3222         for (i = 0; i < ndev; i++) {
3223                 if ((error = spa_config_parse(spa, &vd, dev[i], NULL, 0,
3224                     mode)) != 0)
3225                         goto out;
3226 
3227                 if (!vd->vdev_ops->vdev_op_leaf) {
3228                         vdev_free(vd);
3229                         error = SET_ERROR(EINVAL);
3230                         goto out;
3231                 }
3232 
3233                 /*
3234                  * The L2ARC currently only supports disk devices in
3235                  * kernel context.  For user-level testing, we allow it.
3236                  */
3237 #ifdef _KERNEL
3238                 if ((strcmp(config, ZPOOL_CONFIG_L2CACHE) == 0) &&
3239                     strcmp(vd->vdev_ops->vdev_op_type, VDEV_TYPE_DISK) != 0) {
3240                         error = SET_ERROR(ENOTBLK);
3241                         vdev_free(vd);
3242                         goto out;
3243                 }
3244 #endif
3245                 vd->vdev_top = vd;
3246 
3247                 if ((error = vdev_open(vd)) == 0 &&
3248                     (error = vdev_label_init(vd, crtxg, label)) == 0) {
3249                         VERIFY(nvlist_add_uint64(dev[i], ZPOOL_CONFIG_GUID,
3250                             vd->vdev_guid) == 0);
3251                 }
3252 
3253                 vdev_free(vd);
3254 
3255                 if (error &&
3256                     (mode != VDEV_ALLOC_SPARE && mode != VDEV_ALLOC_L2CACHE))
3257                         goto out;
3258                 else
3259                         error = 0;
3260         }
3261 
3262 out:
3263         sav->sav_pending = NULL;
3264         sav->sav_npending = 0;
3265         return (error);
3266 }
3267 
3268 static int
3269 spa_validate_aux(spa_t *spa, nvlist_t *nvroot, uint64_t crtxg, int mode)
3270 {
3271         int error;
3272 
3273         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
3274 
3275         if ((error = spa_validate_aux_devs(spa, nvroot, crtxg, mode,
3276             &spa->spa_spares, ZPOOL_CONFIG_SPARES, SPA_VERSION_SPARES,
3277             VDEV_LABEL_SPARE)) != 0) {
3278                 return (error);
3279         }
3280 
3281         return (spa_validate_aux_devs(spa, nvroot, crtxg, mode,
3282             &spa->spa_l2cache, ZPOOL_CONFIG_L2CACHE, SPA_VERSION_L2CACHE,
3283             VDEV_LABEL_L2CACHE));
3284 }
3285 
3286 static void
3287 spa_set_aux_vdevs(spa_aux_vdev_t *sav, nvlist_t **devs, int ndevs,
3288     const char *config)
3289 {
3290         int i;
3291 
3292         if (sav->sav_config != NULL) {
3293                 nvlist_t **olddevs;
3294                 uint_t oldndevs;
3295                 nvlist_t **newdevs;
3296 
3297                 /*
3298                  * Generate new dev list by concatentating with the
3299                  * current dev list.
3300                  */
3301                 VERIFY(nvlist_lookup_nvlist_array(sav->sav_config, config,
3302                     &olddevs, &oldndevs) == 0);
3303 
3304                 newdevs = kmem_alloc(sizeof (void *) *
3305                     (ndevs + oldndevs), KM_SLEEP);
3306                 for (i = 0; i < oldndevs; i++)
3307                         VERIFY(nvlist_dup(olddevs[i], &newdevs[i],
3308                             KM_SLEEP) == 0);
3309                 for (i = 0; i < ndevs; i++)
3310                         VERIFY(nvlist_dup(devs[i], &newdevs[i + oldndevs],
3311                             KM_SLEEP) == 0);
3312 
3313                 VERIFY(nvlist_remove(sav->sav_config, config,
3314                     DATA_TYPE_NVLIST_ARRAY) == 0);
3315 
3316                 VERIFY(nvlist_add_nvlist_array(sav->sav_config,
3317                     config, newdevs, ndevs + oldndevs) == 0);
3318                 for (i = 0; i < oldndevs + ndevs; i++)
3319                         nvlist_free(newdevs[i]);
3320                 kmem_free(newdevs, (oldndevs + ndevs) * sizeof (void *));
3321         } else {
3322                 /*
3323                  * Generate a new dev list.
3324                  */
3325                 VERIFY(nvlist_alloc(&sav->sav_config, NV_UNIQUE_NAME,
3326                     KM_SLEEP) == 0);
3327                 VERIFY(nvlist_add_nvlist_array(sav->sav_config, config,
3328                     devs, ndevs) == 0);
3329         }
3330 }
3331 
3332 /*
3333  * Stop and drop level 2 ARC devices
3334  */
3335 void
3336 spa_l2cache_drop(spa_t *spa)
3337 {
3338         vdev_t *vd;
3339         int i;
3340         spa_aux_vdev_t *sav = &spa->spa_l2cache;
3341 
3342         for (i = 0; i < sav->sav_count; i++) {
3343                 uint64_t pool;
3344 
3345                 vd = sav->sav_vdevs[i];
3346                 ASSERT(vd != NULL);
3347 
3348                 if (spa_l2cache_exists(vd->vdev_guid, &pool) &&
3349                     pool != 0ULL && l2arc_vdev_present(vd))
3350                         l2arc_remove_vdev(vd);
3351         }
3352 }
3353 
3354 /*
3355  * Pool Creation
3356  */
3357 int
3358 spa_create(const char *pool, nvlist_t *nvroot, nvlist_t *props,
3359     nvlist_t *zplprops)
3360 {
3361         spa_t *spa;
3362         char *altroot = NULL;
3363         vdev_t *rvd;
3364         dsl_pool_t *dp;
3365         dmu_tx_t *tx;
3366         int error = 0;
3367         uint64_t txg = TXG_INITIAL;
3368         nvlist_t **spares, **l2cache;
3369         uint_t nspares, nl2cache;
3370         uint64_t version, obj;
3371         boolean_t has_features;
3372 
3373         /*
3374          * If this pool already exists, return failure.
3375          */
3376         mutex_enter(&spa_namespace_lock);
3377         if (spa_lookup(pool) != NULL) {
3378                 mutex_exit(&spa_namespace_lock);
3379                 return (SET_ERROR(EEXIST));
3380         }
3381 
3382         /*
3383          * Allocate a new spa_t structure.
3384          */
3385         (void) nvlist_lookup_string(props,
3386             zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
3387         spa = spa_add(pool, NULL, altroot);
3388         spa_activate(spa, spa_mode_global);
3389 
3390         if (props && (error = spa_prop_validate(spa, props))) {
3391                 spa_deactivate(spa);
3392                 spa_remove(spa);
3393                 mutex_exit(&spa_namespace_lock);
3394                 return (error);
3395         }
3396 
3397         has_features = B_FALSE;
3398         for (nvpair_t *elem = nvlist_next_nvpair(props, NULL);
3399             elem != NULL; elem = nvlist_next_nvpair(props, elem)) {
3400                 if (zpool_prop_feature(nvpair_name(elem)))
3401                         has_features = B_TRUE;
3402         }
3403 
3404         if (has_features || nvlist_lookup_uint64(props,
3405             zpool_prop_to_name(ZPOOL_PROP_VERSION), &version) != 0) {
3406                 version = SPA_VERSION;
3407         }
3408         ASSERT(SPA_VERSION_IS_SUPPORTED(version));
3409 
3410         spa->spa_first_txg = txg;
3411         spa->spa_uberblock.ub_txg = txg - 1;
3412         spa->spa_uberblock.ub_version = version;
3413         spa->spa_ubsync = spa->spa_uberblock;
3414 
3415         /*
3416          * Create "The Godfather" zio to hold all async IOs
3417          */
3418         spa->spa_async_zio_root = zio_root(spa, NULL, NULL,
3419             ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_GODFATHER);
3420 
3421         /*
3422          * Create the root vdev.
3423          */
3424         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3425 
3426         error = spa_config_parse(spa, &rvd, nvroot, NULL, 0, VDEV_ALLOC_ADD);
3427 
3428         ASSERT(error != 0 || rvd != NULL);
3429         ASSERT(error != 0 || spa->spa_root_vdev == rvd);
3430 
3431         if (error == 0 && !zfs_allocatable_devs(nvroot))
3432                 error = SET_ERROR(EINVAL);
3433 
3434         if (error == 0 &&
3435             (error = vdev_create(rvd, txg, B_FALSE)) == 0 &&
3436             (error = spa_validate_aux(spa, nvroot, txg,
3437             VDEV_ALLOC_ADD)) == 0) {
3438                 for (int c = 0; c < rvd->vdev_children; c++) {
3439                         vdev_metaslab_set_size(rvd->vdev_child[c]);
3440                         vdev_expand(rvd->vdev_child[c], txg);
3441                 }
3442         }
3443 
3444         spa_config_exit(spa, SCL_ALL, FTAG);
3445 
3446         if (error != 0) {
3447                 spa_unload(spa);
3448                 spa_deactivate(spa);
3449                 spa_remove(spa);
3450                 mutex_exit(&spa_namespace_lock);
3451                 return (error);
3452         }
3453 
3454         /*
3455          * Get the list of spares, if specified.
3456          */
3457         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
3458             &spares, &nspares) == 0) {
3459                 VERIFY(nvlist_alloc(&spa->spa_spares.sav_config, NV_UNIQUE_NAME,
3460                     KM_SLEEP) == 0);
3461                 VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
3462                     ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
3463                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3464                 spa_load_spares(spa);
3465                 spa_config_exit(spa, SCL_ALL, FTAG);
3466                 spa->spa_spares.sav_sync = B_TRUE;
3467         }
3468 
3469         /*
3470          * Get the list of level 2 cache devices, if specified.
3471          */
3472         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
3473             &l2cache, &nl2cache) == 0) {
3474                 VERIFY(nvlist_alloc(&spa->spa_l2cache.sav_config,
3475                     NV_UNIQUE_NAME, KM_SLEEP) == 0);
3476                 VERIFY(nvlist_add_nvlist_array(spa->spa_l2cache.sav_config,
3477                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
3478                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3479                 spa_load_l2cache(spa);
3480                 spa_config_exit(spa, SCL_ALL, FTAG);
3481                 spa->spa_l2cache.sav_sync = B_TRUE;
3482         }
3483 
3484         spa->spa_is_initializing = B_TRUE;
3485         spa->spa_dsl_pool = dp = dsl_pool_create(spa, zplprops, txg);
3486         spa->spa_meta_objset = dp->dp_meta_objset;
3487         spa->spa_is_initializing = B_FALSE;
3488 
3489         /*
3490          * Create DDTs (dedup tables).
3491          */
3492         ddt_create(spa);
3493 
3494         spa_update_dspace(spa);
3495 
3496         tx = dmu_tx_create_assigned(dp, txg);
3497 
3498         /*
3499          * Create the pool config object.
3500          */
3501         spa->spa_config_object = dmu_object_alloc(spa->spa_meta_objset,
3502             DMU_OT_PACKED_NVLIST, SPA_CONFIG_BLOCKSIZE,
3503             DMU_OT_PACKED_NVLIST_SIZE, sizeof (uint64_t), tx);
3504 
3505         if (zap_add(spa->spa_meta_objset,
3506             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CONFIG,
3507             sizeof (uint64_t), 1, &spa->spa_config_object, tx) != 0) {
3508                 cmn_err(CE_PANIC, "failed to add pool config");
3509         }
3510 
3511         if (spa_version(spa) >= SPA_VERSION_FEATURES)
3512                 spa_feature_create_zap_objects(spa, tx);
3513 
3514         if (zap_add(spa->spa_meta_objset,
3515             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CREATION_VERSION,
3516             sizeof (uint64_t), 1, &version, tx) != 0) {
3517                 cmn_err(CE_PANIC, "failed to add pool version");
3518         }
3519 
3520         /* Newly created pools with the right version are always deflated. */
3521         if (version >= SPA_VERSION_RAIDZ_DEFLATE) {
3522                 spa->spa_deflate = TRUE;
3523                 if (zap_add(spa->spa_meta_objset,
3524                     DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
3525                     sizeof (uint64_t), 1, &spa->spa_deflate, tx) != 0) {
3526                         cmn_err(CE_PANIC, "failed to add deflate");
3527                 }
3528         }
3529 
3530         /*
3531          * Create the deferred-free bpobj.  Turn off compression
3532          * because sync-to-convergence takes longer if the blocksize
3533          * keeps changing.
3534          */
3535         obj = bpobj_alloc(spa->spa_meta_objset, 1 << 14, tx);
3536         dmu_object_set_compress(spa->spa_meta_objset, obj,
3537             ZIO_COMPRESS_OFF, tx);
3538         if (zap_add(spa->spa_meta_objset,
3539             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_SYNC_BPOBJ,
3540             sizeof (uint64_t), 1, &obj, tx) != 0) {
3541                 cmn_err(CE_PANIC, "failed to add bpobj");
3542         }
3543         VERIFY3U(0, ==, bpobj_open(&spa->spa_deferred_bpobj,
3544             spa->spa_meta_objset, obj));
3545 
3546         /*
3547          * Create the pool's history object.
3548          */
3549         if (version >= SPA_VERSION_ZPOOL_HISTORY)
3550                 spa_history_create_obj(spa, tx);
3551 
3552         /*
3553          * Set pool properties.
3554          */
3555         spa->spa_bootfs = zpool_prop_default_numeric(ZPOOL_PROP_BOOTFS);
3556         spa->spa_delegation = zpool_prop_default_numeric(ZPOOL_PROP_DELEGATION);
3557         spa->spa_failmode = zpool_prop_default_numeric(ZPOOL_PROP_FAILUREMODE);
3558         spa->spa_autoexpand = zpool_prop_default_numeric(ZPOOL_PROP_AUTOEXPAND);
3559 
3560         if (props != NULL) {
3561                 spa_configfile_set(spa, props, B_FALSE);
3562                 spa_sync_props(props, tx);
3563         }
3564 
3565         dmu_tx_commit(tx);
3566 
3567         spa->spa_sync_on = B_TRUE;
3568         txg_sync_start(spa->spa_dsl_pool);
3569 
3570         /*
3571          * We explicitly wait for the first transaction to complete so that our
3572          * bean counters are appropriately updated.
3573          */
3574         txg_wait_synced(spa->spa_dsl_pool, txg);
3575 
3576         spa_config_sync(spa, B_FALSE, B_TRUE);
3577 
3578         spa_history_log_version(spa, "create");
3579 
3580         spa->spa_minref = refcount_count(&spa->spa_refcount);
3581 
3582         mutex_exit(&spa_namespace_lock);
3583 
3584         return (0);
3585 }
3586 
3587 #ifdef _KERNEL
3588 /*
3589  * Get the root pool information from the root disk, then import the root pool
3590  * during the system boot up time.
3591  */
3592 extern int vdev_disk_read_rootlabel(char *, char *, nvlist_t **);
3593 
3594 static nvlist_t *
3595 spa_generate_rootconf(char *devpath, char *devid, uint64_t *guid)
3596 {
3597         nvlist_t *config;
3598         nvlist_t *nvtop, *nvroot;
3599         uint64_t pgid;
3600 
3601         if (vdev_disk_read_rootlabel(devpath, devid, &config) != 0)
3602                 return (NULL);
3603 
3604         /*
3605          * Add this top-level vdev to the child array.
3606          */
3607         VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3608             &nvtop) == 0);
3609         VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID,
3610             &pgid) == 0);
3611         VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_GUID, guid) == 0);
3612 
3613         /*
3614          * Put this pool's top-level vdevs into a root vdev.
3615          */
3616         VERIFY(nvlist_alloc(&nvroot, NV_UNIQUE_NAME, KM_SLEEP) == 0);
3617         VERIFY(nvlist_add_string(nvroot, ZPOOL_CONFIG_TYPE,
3618             VDEV_TYPE_ROOT) == 0);
3619         VERIFY(nvlist_add_uint64(nvroot, ZPOOL_CONFIG_ID, 0ULL) == 0);
3620         VERIFY(nvlist_add_uint64(nvroot, ZPOOL_CONFIG_GUID, pgid) == 0);
3621         VERIFY(nvlist_add_nvlist_array(nvroot, ZPOOL_CONFIG_CHILDREN,
3622             &nvtop, 1) == 0);
3623 
3624         /*
3625          * Replace the existing vdev_tree with the new root vdev in
3626          * this pool's configuration (remove the old, add the new).
3627          */
3628         VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot) == 0);
3629         nvlist_free(nvroot);
3630         return (config);
3631 }
3632 
3633 /*
3634  * Walk the vdev tree and see if we can find a device with "better"
3635  * configuration. A configuration is "better" if the label on that
3636  * device has a more recent txg.
3637  */
3638 static void
3639 spa_alt_rootvdev(vdev_t *vd, vdev_t **avd, uint64_t *txg)
3640 {
3641         for (int c = 0; c < vd->vdev_children; c++)
3642                 spa_alt_rootvdev(vd->vdev_child[c], avd, txg);
3643 
3644         if (vd->vdev_ops->vdev_op_leaf) {
3645                 nvlist_t *label;
3646                 uint64_t label_txg;
3647 
3648                 if (vdev_disk_read_rootlabel(vd->vdev_physpath, vd->vdev_devid,
3649                     &label) != 0)
3650                         return;
3651 
3652                 VERIFY(nvlist_lookup_uint64(label, ZPOOL_CONFIG_POOL_TXG,
3653                     &label_txg) == 0);
3654 
3655                 /*
3656                  * Do we have a better boot device?
3657                  */
3658                 if (label_txg > *txg) {
3659                         *txg = label_txg;
3660                         *avd = vd;
3661                 }
3662                 nvlist_free(label);
3663         }
3664 }
3665 
3666 /*
3667  * Import a root pool.
3668  *
3669  * For x86. devpath_list will consist of devid and/or physpath name of
3670  * the vdev (e.g. "id1,sd@SSEAGATE..." or "/pci@1f,0/ide@d/disk@0,0:a").
3671  * The GRUB "findroot" command will return the vdev we should boot.
3672  *
3673  * For Sparc, devpath_list consists the physpath name of the booting device
3674  * no matter the rootpool is a single device pool or a mirrored pool.
3675  * e.g.
3676  *      "/pci@1f,0/ide@d/disk@0,0:a"
3677  */
3678 int
3679 spa_import_rootpool(char *devpath, char *devid)
3680 {
3681         spa_t *spa;
3682         vdev_t *rvd, *bvd, *avd = NULL;
3683         nvlist_t *config, *nvtop;
3684         uint64_t guid, txg;
3685         char *pname;
3686         int error;
3687 
3688         /*
3689          * Read the label from the boot device and generate a configuration.
3690          */
3691         config = spa_generate_rootconf(devpath, devid, &guid);
3692 #if defined(_OBP) && defined(_KERNEL)
3693         if (config == NULL) {
3694                 if (strstr(devpath, "/iscsi/ssd") != NULL) {
3695                         /* iscsi boot */
3696                         get_iscsi_bootpath_phy(devpath);
3697                         config = spa_generate_rootconf(devpath, devid, &guid);
3698                 }
3699         }
3700 #endif
3701         if (config == NULL) {
3702                 cmn_err(CE_NOTE, "Cannot read the pool label from '%s'",
3703                     devpath);
3704                 return (SET_ERROR(EIO));
3705         }
3706 
3707         VERIFY(nvlist_lookup_string(config, ZPOOL_CONFIG_POOL_NAME,
3708             &pname) == 0);
3709         VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG, &txg) == 0);
3710 
3711         mutex_enter(&spa_namespace_lock);
3712         if ((spa = spa_lookup(pname)) != NULL) {
3713                 /*
3714                  * Remove the existing root pool from the namespace so that we
3715                  * can replace it with the correct config we just read in.
3716                  */
3717                 spa_remove(spa);
3718         }
3719 
3720         spa = spa_add(pname, config, NULL);
3721         spa->spa_is_root = B_TRUE;
3722         spa->spa_import_flags = ZFS_IMPORT_VERBATIM;
3723 
3724         /*
3725          * Build up a vdev tree based on the boot device's label config.
3726          */
3727         VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3728             &nvtop) == 0);
3729         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3730         error = spa_config_parse(spa, &rvd, nvtop, NULL, 0,
3731             VDEV_ALLOC_ROOTPOOL);
3732         spa_config_exit(spa, SCL_ALL, FTAG);
3733         if (error) {
3734                 mutex_exit(&spa_namespace_lock);
3735                 nvlist_free(config);
3736                 cmn_err(CE_NOTE, "Can not parse the config for pool '%s'",
3737                     pname);
3738                 return (error);
3739         }
3740 
3741         /*
3742          * Get the boot vdev.
3743          */
3744         if ((bvd = vdev_lookup_by_guid(rvd, guid)) == NULL) {
3745                 cmn_err(CE_NOTE, "Can not find the boot vdev for guid %llu",
3746                     (u_longlong_t)guid);
3747                 error = SET_ERROR(ENOENT);
3748                 goto out;
3749         }
3750 
3751         /*
3752          * Determine if there is a better boot device.
3753          */
3754         avd = bvd;
3755         spa_alt_rootvdev(rvd, &avd, &txg);
3756         if (avd != bvd) {
3757                 cmn_err(CE_NOTE, "The boot device is 'degraded'. Please "
3758                     "try booting from '%s'", avd->vdev_path);
3759                 error = SET_ERROR(EINVAL);
3760                 goto out;
3761         }
3762 
3763         /*
3764          * If the boot device is part of a spare vdev then ensure that
3765          * we're booting off the active spare.
3766          */
3767         if (bvd->vdev_parent->vdev_ops == &vdev_spare_ops &&
3768             !bvd->vdev_isspare) {
3769                 cmn_err(CE_NOTE, "The boot device is currently spared. Please "
3770                     "try booting from '%s'",
3771                     bvd->vdev_parent->
3772                     vdev_child[bvd->vdev_parent->vdev_children - 1]->vdev_path);
3773                 error = SET_ERROR(EINVAL);
3774                 goto out;
3775         }
3776 
3777         error = 0;
3778 out:
3779         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3780         vdev_free(rvd);
3781         spa_config_exit(spa, SCL_ALL, FTAG);
3782         mutex_exit(&spa_namespace_lock);
3783 
3784         nvlist_free(config);
3785         return (error);
3786 }
3787 
3788 #endif
3789 
3790 /*
3791  * Import a non-root pool into the system.
3792  */
3793 int
3794 spa_import(const char *pool, nvlist_t *config, nvlist_t *props, uint64_t flags)
3795 {
3796         spa_t *spa;
3797         char *altroot = NULL;
3798         spa_load_state_t state = SPA_LOAD_IMPORT;
3799         zpool_rewind_policy_t policy;
3800         uint64_t mode = spa_mode_global;
3801         uint64_t readonly = B_FALSE;
3802         int error;
3803         nvlist_t *nvroot;
3804         nvlist_t **spares, **l2cache;
3805         uint_t nspares, nl2cache;
3806 
3807         /*
3808          * If a pool with this name exists, return failure.
3809          */
3810         mutex_enter(&spa_namespace_lock);
3811         if (spa_lookup(pool) != NULL) {
3812                 mutex_exit(&spa_namespace_lock);
3813                 return (SET_ERROR(EEXIST));
3814         }
3815 
3816         /*
3817          * Create and initialize the spa structure.
3818          */
3819         (void) nvlist_lookup_string(props,
3820             zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
3821         (void) nvlist_lookup_uint64(props,
3822             zpool_prop_to_name(ZPOOL_PROP_READONLY), &readonly);
3823         if (readonly)
3824                 mode = FREAD;
3825         spa = spa_add(pool, config, altroot);
3826         spa->spa_import_flags = flags;
3827 
3828         /*
3829          * Verbatim import - Take a pool and insert it into the namespace
3830          * as if it had been loaded at boot.
3831          */
3832         if (spa->spa_import_flags & ZFS_IMPORT_VERBATIM) {
3833                 if (props != NULL)
3834                         spa_configfile_set(spa, props, B_FALSE);
3835 
3836                 spa_config_sync(spa, B_FALSE, B_TRUE);
3837 
3838                 mutex_exit(&spa_namespace_lock);
3839                 spa_history_log_version(spa, "import");
3840 
3841                 return (0);
3842         }
3843 
3844         spa_activate(spa, mode);
3845 
3846         /*
3847          * Don't start async tasks until we know everything is healthy.
3848          */
3849         spa_async_suspend(spa);
3850 
3851         zpool_get_rewind_policy(config, &policy);
3852         if (policy.zrp_request & ZPOOL_DO_REWIND)
3853                 state = SPA_LOAD_RECOVER;
3854 
3855         /*
3856          * Pass off the heavy lifting to spa_load().  Pass TRUE for mosconfig
3857          * because the user-supplied config is actually the one to trust when
3858          * doing an import.
3859          */
3860         if (state != SPA_LOAD_RECOVER)
3861                 spa->spa_last_ubsync_txg = spa->spa_load_txg = 0;
3862 
3863         error = spa_load_best(spa, state, B_TRUE, policy.zrp_txg,
3864             policy.zrp_request);
3865 
3866         /*
3867          * Propagate anything learned while loading the pool and pass it
3868          * back to caller (i.e. rewind info, missing devices, etc).
3869          */
3870         VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_LOAD_INFO,
3871             spa->spa_load_info) == 0);
3872 
3873         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3874         /*
3875          * Toss any existing sparelist, as it doesn't have any validity
3876          * anymore, and conflicts with spa_has_spare().
3877          */
3878         if (spa->spa_spares.sav_config) {
3879                 nvlist_free(spa->spa_spares.sav_config);
3880                 spa->spa_spares.sav_config = NULL;
3881                 spa_load_spares(spa);
3882         }
3883         if (spa->spa_l2cache.sav_config) {
3884                 nvlist_free(spa->spa_l2cache.sav_config);
3885                 spa->spa_l2cache.sav_config = NULL;
3886                 spa_load_l2cache(spa);
3887         }
3888 
3889         VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3890             &nvroot) == 0);
3891         if (error == 0)
3892                 error = spa_validate_aux(spa, nvroot, -1ULL,
3893                     VDEV_ALLOC_SPARE);
3894         if (error == 0)
3895                 error = spa_validate_aux(spa, nvroot, -1ULL,
3896                     VDEV_ALLOC_L2CACHE);
3897         spa_config_exit(spa, SCL_ALL, FTAG);
3898 
3899         if (props != NULL)
3900                 spa_configfile_set(spa, props, B_FALSE);
3901 
3902         if (error != 0 || (props && spa_writeable(spa) &&
3903             (error = spa_prop_set(spa, props)))) {
3904                 spa_unload(spa);
3905                 spa_deactivate(spa);
3906                 spa_remove(spa);
3907                 mutex_exit(&spa_namespace_lock);
3908                 return (error);
3909         }
3910 
3911         spa_async_resume(spa);
3912 
3913         /*
3914          * Override any spares and level 2 cache devices as specified by
3915          * the user, as these may have correct device names/devids, etc.
3916          */
3917         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
3918             &spares, &nspares) == 0) {
3919                 if (spa->spa_spares.sav_config)
3920                         VERIFY(nvlist_remove(spa->spa_spares.sav_config,
3921                             ZPOOL_CONFIG_SPARES, DATA_TYPE_NVLIST_ARRAY) == 0);
3922                 else
3923                         VERIFY(nvlist_alloc(&spa->spa_spares.sav_config,
3924                             NV_UNIQUE_NAME, KM_SLEEP) == 0);
3925                 VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
3926                     ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
3927                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3928                 spa_load_spares(spa);
3929                 spa_config_exit(spa, SCL_ALL, FTAG);
3930                 spa->spa_spares.sav_sync = B_TRUE;
3931         }
3932         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
3933             &l2cache, &nl2cache) == 0) {
3934                 if (spa->spa_l2cache.sav_config)
3935                         VERIFY(nvlist_remove(spa->spa_l2cache.sav_config,
3936                             ZPOOL_CONFIG_L2CACHE, DATA_TYPE_NVLIST_ARRAY) == 0);
3937                 else
3938                         VERIFY(nvlist_alloc(&spa->spa_l2cache.sav_config,
3939                             NV_UNIQUE_NAME, KM_SLEEP) == 0);
3940                 VERIFY(nvlist_add_nvlist_array(spa->spa_l2cache.sav_config,
3941                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
3942                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3943                 spa_load_l2cache(spa);
3944                 spa_config_exit(spa, SCL_ALL, FTAG);
3945                 spa->spa_l2cache.sav_sync = B_TRUE;
3946         }
3947 
3948         /*
3949          * Check for any removed devices.
3950          */
3951         if (spa->spa_autoreplace) {
3952                 spa_aux_check_removed(&spa->spa_spares);
3953                 spa_aux_check_removed(&spa->spa_l2cache);
3954         }
3955 
3956         if (spa_writeable(spa)) {
3957                 /*
3958                  * Update the config cache to include the newly-imported pool.
3959                  */
3960                 spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
3961         }
3962 
3963         /*
3964          * It's possible that the pool was expanded while it was exported.
3965          * We kick off an async task to handle this for us.
3966          */
3967         spa_async_request(spa, SPA_ASYNC_AUTOEXPAND);
3968 
3969         mutex_exit(&spa_namespace_lock);
3970         spa_history_log_version(spa, "import");
3971 
3972         return (0);
3973 }
3974 
3975 nvlist_t *
3976 spa_tryimport(nvlist_t *tryconfig)
3977 {
3978         nvlist_t *config = NULL;
3979         char *poolname;
3980         spa_t *spa;
3981         uint64_t state;
3982         int error;
3983 
3984         if (nvlist_lookup_string(tryconfig, ZPOOL_CONFIG_POOL_NAME, &poolname))
3985                 return (NULL);
3986 
3987         if (nvlist_lookup_uint64(tryconfig, ZPOOL_CONFIG_POOL_STATE, &state))
3988                 return (NULL);
3989 
3990         /*
3991          * Create and initialize the spa structure.
3992          */
3993         mutex_enter(&spa_namespace_lock);
3994         spa = spa_add(TRYIMPORT_NAME, tryconfig, NULL);
3995         spa_activate(spa, FREAD);
3996 
3997         /*
3998          * Pass off the heavy lifting to spa_load().
3999          * Pass TRUE for mosconfig because the user-supplied config
4000          * is actually the one to trust when doing an import.
4001          */
4002         error = spa_load(spa, SPA_LOAD_TRYIMPORT, SPA_IMPORT_EXISTING, B_TRUE);
4003 
4004         /*
4005          * If 'tryconfig' was at least parsable, return the current config.
4006          */
4007         if (spa->spa_root_vdev != NULL) {
4008                 config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
4009                 VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME,
4010                     poolname) == 0);
4011                 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,
4012                     state) == 0);
4013                 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_TIMESTAMP,
4014                     spa->spa_uberblock.ub_timestamp) == 0);
4015                 VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_LOAD_INFO,
4016                     spa->spa_load_info) == 0);
4017 
4018                 /*
4019                  * If the bootfs property exists on this pool then we
4020                  * copy it out so that external consumers can tell which
4021                  * pools are bootable.
4022                  */
4023                 if ((!error || error == EEXIST) && spa->spa_bootfs) {
4024                         char *tmpname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
4025 
4026                         /*
4027                          * We have to play games with the name since the
4028                          * pool was opened as TRYIMPORT_NAME.
4029                          */
4030                         if (dsl_dsobj_to_dsname(spa_name(spa),
4031                             spa->spa_bootfs, tmpname) == 0) {
4032                                 char *cp;
4033                                 char *dsname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
4034 
4035                                 cp = strchr(tmpname, '/');
4036                                 if (cp == NULL) {
4037                                         (void) strlcpy(dsname, tmpname,
4038                                             MAXPATHLEN);
4039                                 } else {
4040                                         (void) snprintf(dsname, MAXPATHLEN,
4041                                             "%s/%s", poolname, ++cp);
4042                                 }
4043                                 VERIFY(nvlist_add_string(config,
4044                                     ZPOOL_CONFIG_BOOTFS, dsname) == 0);
4045                                 kmem_free(dsname, MAXPATHLEN);
4046                         }
4047                         kmem_free(tmpname, MAXPATHLEN);
4048                 }
4049 
4050                 /*
4051                  * Add the list of hot spares and level 2 cache devices.
4052                  */
4053                 spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
4054                 spa_add_spares(spa, config);
4055                 spa_add_l2cache(spa, config);
4056                 spa_config_exit(spa, SCL_CONFIG, FTAG);
4057         }
4058 
4059         spa_unload(spa);
4060         spa_deactivate(spa);
4061         spa_remove(spa);
4062         mutex_exit(&spa_namespace_lock);
4063 
4064         return (config);
4065 }
4066 
4067 /*
4068  * Pool export/destroy
4069  *
4070  * The act of destroying or exporting a pool is very simple.  We make sure there
4071  * is no more pending I/O and any references to the pool are gone.  Then, we
4072  * update the pool state and sync all the labels to disk, removing the
4073  * configuration from the cache afterwards. If the 'hardforce' flag is set, then
4074  * we don't sync the labels or remove the configuration cache.
4075  */
4076 static int
4077 spa_export_common(char *pool, int new_state, nvlist_t **oldconfig,
4078     boolean_t force, boolean_t hardforce)
4079 {
4080         spa_t *spa;
4081 
4082         if (oldconfig)
4083                 *oldconfig = NULL;
4084 
4085         if (!(spa_mode_global & FWRITE))
4086                 return (SET_ERROR(EROFS));
4087 
4088         mutex_enter(&spa_namespace_lock);
4089         if ((spa = spa_lookup(pool)) == NULL) {
4090                 mutex_exit(&spa_namespace_lock);
4091                 return (SET_ERROR(ENOENT));
4092         }
4093 
4094         /*
4095          * Put a hold on the pool, drop the namespace lock, stop async tasks,
4096          * reacquire the namespace lock, and see if we can export.
4097          */
4098         spa_open_ref(spa, FTAG);
4099         mutex_exit(&spa_namespace_lock);
4100         spa_async_suspend(spa);
4101         mutex_enter(&spa_namespace_lock);
4102         spa_close(spa, FTAG);
4103 
4104         /*
4105          * The pool will be in core if it's openable,
4106          * in which case we can modify its state.
4107          */
4108         if (spa->spa_state != POOL_STATE_UNINITIALIZED && spa->spa_sync_on) {
4109                 /*
4110                  * Objsets may be open only because they're dirty, so we
4111                  * have to force it to sync before checking spa_refcnt.
4112                  */
4113                 txg_wait_synced(spa->spa_dsl_pool, 0);
4114 
4115                 /*
4116                  * A pool cannot be exported or destroyed if there are active
4117                  * references.  If we are resetting a pool, allow references by
4118                  * fault injection handlers.
4119                  */
4120                 if (!spa_refcount_zero(spa) ||
4121                     (spa->spa_inject_ref != 0 &&
4122                     new_state != POOL_STATE_UNINITIALIZED)) {
4123                         spa_async_resume(spa);
4124                         mutex_exit(&spa_namespace_lock);
4125                         return (SET_ERROR(EBUSY));
4126                 }
4127 
4128                 /*
4129                  * A pool cannot be exported if it has an active shared spare.
4130                  * This is to prevent other pools stealing the active spare
4131                  * from an exported pool. At user's own will, such pool can
4132                  * be forcedly exported.
4133                  */
4134                 if (!force && new_state == POOL_STATE_EXPORTED &&
4135                     spa_has_active_shared_spare(spa)) {
4136                         spa_async_resume(spa);
4137                         mutex_exit(&spa_namespace_lock);
4138                         return (SET_ERROR(EXDEV));
4139                 }
4140 
4141                 /*
4142                  * We want this to be reflected on every label,
4143                  * so mark them all dirty.  spa_unload() will do the
4144                  * final sync that pushes these changes out.
4145                  */
4146                 if (new_state != POOL_STATE_UNINITIALIZED && !hardforce) {
4147                         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
4148                         spa->spa_state = new_state;
4149                         spa->spa_final_txg = spa_last_synced_txg(spa) +
4150                             TXG_DEFER_SIZE + 1;
4151                         vdev_config_dirty(spa->spa_root_vdev);
4152                         spa_config_exit(spa, SCL_ALL, FTAG);
4153                 }
4154         }
4155 
4156         spa_event_notify(spa, NULL, ESC_ZFS_POOL_DESTROY);
4157 
4158         if (spa->spa_state != POOL_STATE_UNINITIALIZED) {
4159                 spa_unload(spa);
4160                 spa_deactivate(spa);
4161         }
4162 
4163         if (oldconfig && spa->spa_config)
4164                 VERIFY(nvlist_dup(spa->spa_config, oldconfig, 0) == 0);
4165 
4166         if (new_state != POOL_STATE_UNINITIALIZED) {
4167                 if (!hardforce)
4168                         spa_config_sync(spa, B_TRUE, B_TRUE);
4169                 spa_remove(spa);
4170         }
4171         mutex_exit(&spa_namespace_lock);
4172 
4173         return (0);
4174 }
4175 
4176 /*
4177  * Destroy a storage pool.
4178  */
4179 int
4180 spa_destroy(char *pool)
4181 {
4182         return (spa_export_common(pool, POOL_STATE_DESTROYED, NULL,
4183             B_FALSE, B_FALSE));
4184 }
4185 
4186 /*
4187  * Export a storage pool.
4188  */
4189 int
4190 spa_export(char *pool, nvlist_t **oldconfig, boolean_t force,
4191     boolean_t hardforce)
4192 {
4193         return (spa_export_common(pool, POOL_STATE_EXPORTED, oldconfig,
4194             force, hardforce));
4195 }
4196 
4197 /*
4198  * Similar to spa_export(), this unloads the spa_t without actually removing it
4199  * from the namespace in any way.
4200  */
4201 int
4202 spa_reset(char *pool)
4203 {
4204         return (spa_export_common(pool, POOL_STATE_UNINITIALIZED, NULL,
4205             B_FALSE, B_FALSE));
4206 }
4207 
4208 /*
4209  * ==========================================================================
4210  * Device manipulation
4211  * ==========================================================================
4212  */
4213 
4214 /*
4215  * Add a device to a storage pool.
4216  */
4217 int
4218 spa_vdev_add(spa_t *spa, nvlist_t *nvroot)
4219 {
4220         uint64_t txg, id;
4221         int error;
4222         vdev_t *rvd = spa->spa_root_vdev;
4223         vdev_t *vd, *tvd;
4224         nvlist_t **spares, **l2cache;
4225         uint_t nspares, nl2cache;
4226 
4227         ASSERT(spa_writeable(spa));
4228 
4229         txg = spa_vdev_enter(spa);
4230 
4231         if ((error = spa_config_parse(spa, &vd, nvroot, NULL, 0,
4232             VDEV_ALLOC_ADD)) != 0)
4233                 return (spa_vdev_exit(spa, NULL, txg, error));
4234 
4235         spa->spa_pending_vdev = vd;  /* spa_vdev_exit() will clear this */
4236 
4237         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES, &spares,
4238             &nspares) != 0)
4239                 nspares = 0;
4240 
4241         if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE, &l2cache,
4242             &nl2cache) != 0)
4243                 nl2cache = 0;
4244 
4245         if (vd->vdev_children == 0 && nspares == 0 && nl2cache == 0)
4246                 return (spa_vdev_exit(spa, vd, txg, EINVAL));
4247 
4248         if (vd->vdev_children != 0 &&
4249             (error = vdev_create(vd, txg, B_FALSE)) != 0)
4250                 return (spa_vdev_exit(spa, vd, txg, error));
4251 
4252         /*
4253          * We must validate the spares and l2cache devices after checking the
4254          * children.  Otherwise, vdev_inuse() will blindly overwrite the spare.
4255          */
4256         if ((error = spa_validate_aux(spa, nvroot, txg, VDEV_ALLOC_ADD)) != 0)
4257                 return (spa_vdev_exit(spa, vd, txg, error));
4258 
4259         /*
4260          * Transfer each new top-level vdev from vd to rvd.
4261          */
4262         for (int c = 0; c < vd->vdev_children; c++) {
4263 
4264                 /*
4265                  * Set the vdev id to the first hole, if one exists.
4266                  */
4267                 for (id = 0; id < rvd->vdev_children; id++) {
4268                         if (rvd->vdev_child[id]->vdev_ishole) {
4269                                 vdev_free(rvd->vdev_child[id]);
4270                                 break;
4271                         }
4272                 }
4273                 tvd = vd->vdev_child[c];
4274                 vdev_remove_child(vd, tvd);
4275                 tvd->vdev_id = id;
4276                 vdev_add_child(rvd, tvd);
4277                 vdev_config_dirty(tvd);
4278         }
4279 
4280         if (nspares != 0) {
4281                 spa_set_aux_vdevs(&spa->spa_spares, spares, nspares,
4282                     ZPOOL_CONFIG_SPARES);
4283                 spa_load_spares(spa);
4284                 spa->spa_spares.sav_sync = B_TRUE;
4285         }
4286 
4287         if (nl2cache != 0) {
4288                 spa_set_aux_vdevs(&spa->spa_l2cache, l2cache, nl2cache,
4289                     ZPOOL_CONFIG_L2CACHE);
4290                 spa_load_l2cache(spa);
4291                 spa->spa_l2cache.sav_sync = B_TRUE;
4292         }
4293 
4294         /*
4295          * We have to be careful when adding new vdevs to an existing pool.
4296          * If other threads start allocating from these vdevs before we
4297          * sync the config cache, and we lose power, then upon reboot we may
4298          * fail to open the pool because there are DVAs that the config cache
4299          * can't translate.  Therefore, we first add the vdevs without
4300          * initializing metaslabs; sync the config cache (via spa_vdev_exit());
4301          * and then let spa_config_update() initialize the new metaslabs.
4302          *
4303          * spa_load() checks for added-but-not-initialized vdevs, so that
4304          * if we lose power at any point in this sequence, the remaining
4305          * steps will be completed the next time we load the pool.
4306          */
4307         (void) spa_vdev_exit(spa, vd, txg, 0);
4308 
4309         mutex_enter(&spa_namespace_lock);
4310         spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
4311         mutex_exit(&spa_namespace_lock);
4312 
4313         return (0);
4314 }
4315 
4316 /*
4317  * Attach a device to a mirror.  The arguments are the path to any device
4318  * in the mirror, and the nvroot for the new device.  If the path specifies
4319  * a device that is not mirrored, we automatically insert the mirror vdev.
4320  *
4321  * If 'replacing' is specified, the new device is intended to replace the
4322  * existing device; in this case the two devices are made into their own
4323  * mirror using the 'replacing' vdev, which is functionally identical to
4324  * the mirror vdev (it actually reuses all the same ops) but has a few
4325  * extra rules: you can't attach to it after it's been created, and upon
4326  * completion of resilvering, the first disk (the one being replaced)
4327  * is automatically detached.
4328  */
4329 int
4330 spa_vdev_attach(spa_t *spa, uint64_t guid, nvlist_t *nvroot, int replacing)
4331 {
4332         uint64_t txg, dtl_max_txg;
4333         vdev_t *rvd = spa->spa_root_vdev;
4334         vdev_t *oldvd, *newvd, *newrootvd, *pvd, *tvd;
4335         vdev_ops_t *pvops;
4336         char *oldvdpath, *newvdpath;
4337         int newvd_isspare;
4338         int error;
4339 
4340         ASSERT(spa_writeable(spa));
4341 
4342         txg = spa_vdev_enter(spa);
4343 
4344         oldvd = spa_lookup_by_guid(spa, guid, B_FALSE);
4345 
4346         if (oldvd == NULL)
4347                 return (spa_vdev_exit(spa, NULL, txg, ENODEV));
4348 
4349         if (!oldvd->vdev_ops->vdev_op_leaf)
4350                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4351 
4352         pvd = oldvd->vdev_parent;
4353 
4354         if ((error = spa_config_parse(spa, &newrootvd, nvroot, NULL, 0,
4355             VDEV_ALLOC_ATTACH)) != 0)
4356                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4357 
4358         if (newrootvd->vdev_children != 1)
4359                 return (spa_vdev_exit(spa, newrootvd, txg, EINVAL));
4360 
4361         newvd = newrootvd->vdev_child[0];
4362 
4363         if (!newvd->vdev_ops->vdev_op_leaf)
4364                 return (spa_vdev_exit(spa, newrootvd, txg, EINVAL));
4365 
4366         if ((error = vdev_create(newrootvd, txg, replacing)) != 0)
4367                 return (spa_vdev_exit(spa, newrootvd, txg, error));
4368 
4369         /*
4370          * Spares can't replace logs
4371          */
4372         if (oldvd->vdev_top->vdev_islog && newvd->vdev_isspare)
4373                 return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4374 
4375         if (!replacing) {
4376                 /*
4377                  * For attach, the only allowable parent is a mirror or the root
4378                  * vdev.
4379                  */
4380                 if (pvd->vdev_ops != &vdev_mirror_ops &&
4381                     pvd->vdev_ops != &vdev_root_ops)
4382                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4383 
4384                 pvops = &vdev_mirror_ops;
4385         } else {
4386                 /*
4387                  * Active hot spares can only be replaced by inactive hot
4388                  * spares.
4389                  */
4390                 if (pvd->vdev_ops == &vdev_spare_ops &&
4391                     oldvd->vdev_isspare &&
4392                     !spa_has_spare(spa, newvd->vdev_guid))
4393                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4394 
4395                 /*
4396                  * If the source is a hot spare, and the parent isn't already a
4397                  * spare, then we want to create a new hot spare.  Otherwise, we
4398                  * want to create a replacing vdev.  The user is not allowed to
4399                  * attach to a spared vdev child unless the 'isspare' state is
4400                  * the same (spare replaces spare, non-spare replaces
4401                  * non-spare).
4402                  */
4403                 if (pvd->vdev_ops == &vdev_replacing_ops &&
4404                     spa_version(spa) < SPA_VERSION_MULTI_REPLACE) {
4405                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4406                 } else if (pvd->vdev_ops == &vdev_spare_ops &&
4407                     newvd->vdev_isspare != oldvd->vdev_isspare) {
4408                         return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4409                 }
4410 
4411                 if (newvd->vdev_isspare)
4412                         pvops = &vdev_spare_ops;
4413                 else
4414                         pvops = &vdev_replacing_ops;
4415         }
4416 
4417         /*
4418          * Make sure the new device is big enough.
4419          */
4420         if (newvd->vdev_asize < vdev_get_min_asize(oldvd))
4421                 return (spa_vdev_exit(spa, newrootvd, txg, EOVERFLOW));
4422 
4423         /*
4424          * The new device cannot have a higher alignment requirement
4425          * than the top-level vdev.
4426          */
4427         if (newvd->vdev_ashift > oldvd->vdev_top->vdev_ashift)
4428                 return (spa_vdev_exit(spa, newrootvd, txg, EDOM));
4429 
4430         /*
4431          * If this is an in-place replacement, update oldvd's path and devid
4432          * to make it distinguishable from newvd, and unopenable from now on.
4433          */
4434         if (strcmp(oldvd->vdev_path, newvd->vdev_path) == 0) {
4435                 spa_strfree(oldvd->vdev_path);
4436                 oldvd->vdev_path = kmem_alloc(strlen(newvd->vdev_path) + 5,
4437                     KM_SLEEP);
4438                 (void) sprintf(oldvd->vdev_path, "%s/%s",
4439                     newvd->vdev_path, "old");
4440                 if (oldvd->vdev_devid != NULL) {
4441                         spa_strfree(oldvd->vdev_devid);
4442                         oldvd->vdev_devid = NULL;
4443                 }
4444         }
4445 
4446         /* mark the device being resilvered */
4447         newvd->vdev_resilvering = B_TRUE;
4448 
4449         /*
4450          * If the parent is not a mirror, or if we're replacing, insert the new
4451          * mirror/replacing/spare vdev above oldvd.
4452          */
4453         if (pvd->vdev_ops != pvops)
4454                 pvd = vdev_add_parent(oldvd, pvops);
4455 
4456         ASSERT(pvd->vdev_top->vdev_parent == rvd);
4457         ASSERT(pvd->vdev_ops == pvops);
4458         ASSERT(oldvd->vdev_parent == pvd);
4459 
4460         /*
4461          * Extract the new device from its root and add it to pvd.
4462          */
4463         vdev_remove_child(newrootvd, newvd);
4464         newvd->vdev_id = pvd->vdev_children;
4465         newvd->vdev_crtxg = oldvd->vdev_crtxg;
4466         vdev_add_child(pvd, newvd);
4467 
4468         tvd = newvd->vdev_top;
4469         ASSERT(pvd->vdev_top == tvd);
4470         ASSERT(tvd->vdev_parent == rvd);
4471 
4472         vdev_config_dirty(tvd);
4473 
4474         /*
4475          * Set newvd's DTL to [TXG_INITIAL, dtl_max_txg) so that we account
4476          * for any dmu_sync-ed blocks.  It will propagate upward when
4477          * spa_vdev_exit() calls vdev_dtl_reassess().
4478          */
4479         dtl_max_txg = txg + TXG_CONCURRENT_STATES;
4480 
4481         vdev_dtl_dirty(newvd, DTL_MISSING, TXG_INITIAL,
4482             dtl_max_txg - TXG_INITIAL);
4483 
4484         if (newvd->vdev_isspare) {
4485                 spa_spare_activate(newvd);
4486                 spa_event_notify(spa, newvd, ESC_ZFS_VDEV_SPARE);
4487         }
4488 
4489         oldvdpath = spa_strdup(oldvd->vdev_path);
4490         newvdpath = spa_strdup(newvd->vdev_path);
4491         newvd_isspare = newvd->vdev_isspare;
4492 
4493         /*
4494          * Mark newvd's DTL dirty in this txg.
4495          */
4496         vdev_dirty(tvd, VDD_DTL, newvd, txg);
4497 
4498         /*
4499          * Restart the resilver
4500          */
4501         dsl_resilver_restart(spa->spa_dsl_pool, dtl_max_txg);
4502 
4503         /*
4504          * Commit the config
4505          */
4506         (void) spa_vdev_exit(spa, newrootvd, dtl_max_txg, 0);
4507 
4508         spa_history_log_internal(spa, "vdev attach", NULL,
4509             "%s vdev=%s %s vdev=%s",
4510             replacing && newvd_isspare ? "spare in" :
4511             replacing ? "replace" : "attach", newvdpath,
4512             replacing ? "for" : "to", oldvdpath);
4513 
4514         spa_strfree(oldvdpath);
4515         spa_strfree(newvdpath);
4516 
4517         if (spa->spa_bootfs)
4518                 spa_event_notify(spa, newvd, ESC_ZFS_BOOTFS_VDEV_ATTACH);
4519 
4520         return (0);
4521 }
4522 
4523 /*
4524  * Detach a device from a mirror or replacing vdev.
4525  *
4526  * If 'replace_done' is specified, only detach if the parent
4527  * is a replacing vdev.
4528  */
4529 int
4530 spa_vdev_detach(spa_t *spa, uint64_t guid, uint64_t pguid, int replace_done)
4531 {
4532         uint64_t txg;
4533         int error;
4534         vdev_t *rvd = spa->spa_root_vdev;
4535         vdev_t *vd, *pvd, *cvd, *tvd;
4536         boolean_t unspare = B_FALSE;
4537         uint64_t unspare_guid = 0;
4538         char *vdpath;
4539 
4540         ASSERT(spa_writeable(spa));
4541 
4542         txg = spa_vdev_enter(spa);
4543 
4544         vd = spa_lookup_by_guid(spa, guid, B_FALSE);
4545 
4546         if (vd == NULL)
4547                 return (spa_vdev_exit(spa, NULL, txg, ENODEV));
4548 
4549         if (!vd->vdev_ops->vdev_op_leaf)
4550                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4551 
4552         pvd = vd->vdev_parent;
4553 
4554         /*
4555          * If the parent/child relationship is not as expected, don't do it.
4556          * Consider M(A,R(B,C)) -- that is, a mirror of A with a replacing
4557          * vdev that's replacing B with C.  The user's intent in replacing
4558          * is to go from M(A,B) to M(A,C).  If the user decides to cancel
4559          * the replace by detaching C, the expected behavior is to end up
4560          * M(A,B).  But suppose that right after deciding to detach C,
4561          * the replacement of B completes.  We would have M(A,C), and then
4562          * ask to detach C, which would leave us with just A -- not what
4563          * the user wanted.  To prevent this, we make sure that the
4564          * parent/child relationship hasn't changed -- in this example,
4565          * that C's parent is still the replacing vdev R.
4566          */
4567         if (pvd->vdev_guid != pguid && pguid != 0)
4568                 return (spa_vdev_exit(spa, NULL, txg, EBUSY));
4569 
4570         /*
4571          * Only 'replacing' or 'spare' vdevs can be replaced.
4572          */
4573         if (replace_done && pvd->vdev_ops != &vdev_replacing_ops &&
4574             pvd->vdev_ops != &vdev_spare_ops)
4575                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4576 
4577         ASSERT(pvd->vdev_ops != &vdev_spare_ops ||
4578             spa_version(spa) >= SPA_VERSION_SPARES);
4579 
4580         /*
4581          * Only mirror, replacing, and spare vdevs support detach.
4582          */
4583         if (pvd->vdev_ops != &vdev_replacing_ops &&
4584             pvd->vdev_ops != &vdev_mirror_ops &&
4585             pvd->vdev_ops != &vdev_spare_ops)
4586                 return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4587 
4588         /*
4589          * If this device has the only valid copy of some data,
4590          * we cannot safely detach it.
4591          */
4592         if (vdev_dtl_required(vd))
4593                 return (spa_vdev_exit(spa, NULL, txg, EBUSY));
4594 
4595         ASSERT(pvd->vdev_children >= 2);
4596 
4597         /*
4598          * If we are detaching the second disk from a replacing vdev, then
4599          * check to see if we changed the original vdev's path to have "/old"
4600          * at the end in spa_vdev_attach().  If so, undo that change now.
4601          */
4602         if (pvd->vdev_ops == &vdev_replacing_ops && vd->vdev_id > 0 &&
4603             vd->vdev_path != NULL) {
4604                 size_t len = strlen(vd->vdev_path);
4605 
4606                 for (int c = 0; c < pvd->vdev_children; c++) {
4607                         cvd = pvd->vdev_child[c];
4608 
4609                         if (cvd == vd || cvd->vdev_path == NULL)
4610                                 continue;
4611 
4612                         if (strncmp(cvd->vdev_path, vd->vdev_path, len) == 0 &&
4613                             strcmp(cvd->vdev_path + len, "/old") == 0) {
4614                                 spa_strfree(cvd->vdev_path);
4615                                 cvd->vdev_path = spa_strdup(vd->vdev_path);
4616                                 break;
4617                         }
4618                 }
4619         }
4620 
4621         /*
4622          * If we are detaching the original disk from a spare, then it implies
4623          * that the spare should become a real disk, and be removed from the
4624          * active spare list for the pool.
4625          */
4626         if (pvd->vdev_ops == &vdev_spare_ops &&
4627             vd->vdev_id == 0 &&
4628             pvd->vdev_child[pvd->vdev_children - 1]->vdev_isspare)
4629                 unspare = B_TRUE;
4630 
4631         /*
4632          * Erase the disk labels so the disk can be used for other things.
4633          * This must be done after all other error cases are handled,
4634          * but before we disembowel vd (so we can still do I/O to it).
4635          * But if we can't do it, don't treat the error as fatal --
4636          * it may be that the unwritability of the disk is the reason
4637          * it's being detached!
4638          */
4639         error = vdev_label_init(vd, 0, VDEV_LABEL_REMOVE);
4640 
4641         /*
4642          * Remove vd from its parent and compact the parent's children.
4643          */
4644         vdev_remove_child(pvd, vd);
4645         vdev_compact_children(pvd);
4646 
4647         /*
4648          * Remember one of the remaining children so we can get tvd below.
4649          */
4650         cvd = pvd->vdev_child[pvd->vdev_children - 1];
4651 
4652         /*
4653          * If we need to remove the remaining child from the list of hot spares,
4654          * do it now, marking the vdev as no longer a spare in the process.
4655          * We must do this before vdev_remove_parent(), because that can
4656          * change the GUID if it creates a new toplevel GUID.  For a similar
4657          * reason, we must remove the spare now, in the same txg as the detach;
4658          * otherwise someone could attach a new sibling, change the GUID, and
4659          * the subsequent attempt to spa_vdev_remove(unspare_guid) would fail.
4660          */
4661         if (unspare) {
4662                 ASSERT(cvd->vdev_isspare);
4663                 spa_spare_remove(cvd);
4664                 unspare_guid = cvd->vdev_guid;
4665                 (void) spa_vdev_remove(spa, unspare_guid, B_TRUE);
4666                 cvd->vdev_unspare = B_TRUE;
4667         }
4668 
4669         /*
4670          * If the parent mirror/replacing vdev only has one child,
4671          * the parent is no longer needed.  Remove it from the tree.
4672          */
4673         if (pvd->vdev_children == 1) {
4674                 if (pvd->vdev_ops == &vdev_spare_ops)
4675                         cvd->vdev_unspare = B_FALSE;
4676                 vdev_remove_parent(cvd);
4677                 cvd->vdev_resilvering = B_FALSE;
4678         }
4679 
4680 
4681         /*
4682          * We don't set tvd until now because the parent we just removed
4683          * may have been the previous top-level vdev.
4684          */
4685         tvd = cvd->vdev_top;
4686         ASSERT(tvd->vdev_parent == rvd);
4687 
4688         /*
4689          * Reevaluate the parent vdev state.
4690          */
4691         vdev_propagate_state(cvd);
4692 
4693         /*
4694          * If the 'autoexpand' property is set on the pool then automatically
4695          * try to expand the size of the pool. For example if the device we
4696          * just detached was smaller than the others, it may be possible to
4697          * add metaslabs (i.e. grow the pool). We need to reopen the vdev
4698          * first so that we can obtain the updated sizes of the leaf vdevs.
4699          */
4700         if (spa->spa_autoexpand) {
4701                 vdev_reopen(tvd);
4702                 vdev_expand(tvd, txg);
4703         }
4704 
4705         vdev_config_dirty(tvd);
4706 
4707         /*
4708          * Mark vd's DTL as dirty in this txg.  vdev_dtl_sync() will see that
4709          * vd->vdev_detached is set and free vd's DTL object in syncing context.
4710          * But first make sure we're not on any *other* txg's DTL list, to
4711          * prevent vd from being accessed after it's freed.
4712          */
4713         vdpath = spa_strdup(vd->vdev_path);
4714         for (int t = 0; t < TXG_SIZE; t++)
4715                 (void) txg_list_remove_this(&tvd->vdev_dtl_list, vd, t);
4716         vd->vdev_detached = B_TRUE;
4717         vdev_dirty(tvd, VDD_DTL, vd, txg);
4718 
4719         spa_event_notify(spa, vd, ESC_ZFS_VDEV_REMOVE);
4720 
4721         /* hang on to the spa before we release the lock */
4722         spa_open_ref(spa, FTAG);
4723 
4724         error = spa_vdev_exit(spa, vd, txg, 0);
4725 
4726         spa_history_log_internal(spa, "detach", NULL,
4727             "vdev=%s", vdpath);
4728         spa_strfree(vdpath);
4729 
4730         /*
4731          * If this was the removal of the original device in a hot spare vdev,
4732          * then we want to go through and remove the device from the hot spare
4733          * list of every other pool.
4734          */
4735         if (unspare) {
4736                 spa_t *altspa = NULL;
4737 
4738                 mutex_enter(&spa_namespace_lock);
4739                 while ((altspa = spa_next(altspa)) != NULL) {
4740                         if (altspa->spa_state != POOL_STATE_ACTIVE ||
4741                             altspa == spa)
4742                                 continue;
4743 
4744                         spa_open_ref(altspa, FTAG);
4745                         mutex_exit(&spa_namespace_lock);
4746                         (void) spa_vdev_remove(altspa, unspare_guid, B_TRUE);
4747                         mutex_enter(&spa_namespace_lock);
4748                         spa_close(altspa, FTAG);
4749                 }
4750                 mutex_exit(&spa_namespace_lock);
4751 
4752                 /* search the rest of the vdevs for spares to remove */
4753                 spa_vdev_resilver_done(spa);
4754         }
4755 
4756         /* all done with the spa; OK to release */
4757         mutex_enter(&spa_namespace_lock);
4758         spa_close(spa, FTAG);
4759         mutex_exit(&spa_namespace_lock);
4760 
4761         return (error);
4762 }
4763 
4764 /*
4765  * Split a set of devices from their mirrors, and create a new pool from them.
4766  */
4767 int
4768 spa_vdev_split_mirror(spa_t *spa, char *newname, nvlist_t *config,
4769     nvlist_t *props, boolean_t exp)
4770 {
4771         int error = 0;
4772         uint64_t txg, *glist;
4773         spa_t *newspa;
4774         uint_t c, children, lastlog;
4775         nvlist_t **child, *nvl, *tmp;
4776         dmu_tx_t *tx;
4777         char *altroot = NULL;
4778         vdev_t *rvd, **vml = NULL;                      /* vdev modify list */
4779         boolean_t activate_slog;
4780 
4781         ASSERT(spa_writeable(spa));
4782 
4783         txg = spa_vdev_enter(spa);
4784 
4785         /* clear the log and flush everything up to now */
4786         activate_slog = spa_passivate_log(spa);
4787         (void) spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
4788         error = spa_offline_log(spa);
4789         txg = spa_vdev_config_enter(spa);
4790 
4791         if (activate_slog)
4792                 spa_activate_log(spa);
4793 
4794         if (error != 0)
4795                 return (spa_vdev_exit(spa, NULL, txg, error));
4796 
4797         /* check new spa name before going any further */
4798         if (spa_lookup(newname) != NULL)
4799                 return (spa_vdev_exit(spa, NULL, txg, EEXIST));
4800 
4801         /*
4802          * scan through all the children to ensure they're all mirrors
4803          */
4804         if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nvl) != 0 ||
4805             nvlist_lookup_nvlist_array(nvl, ZPOOL_CONFIG_CHILDREN, &child,
4806             &children) != 0)
4807                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4808 
4809         /* first, check to ensure we've got the right child count */
4810         rvd = spa->spa_root_vdev;
4811         lastlog = 0;
4812         for (c = 0; c < rvd->vdev_children; c++) {
4813                 vdev_t *vd = rvd->vdev_child[c];
4814 
4815                 /* don't count the holes & logs as children */
4816                 if (vd->vdev_islog || vd->vdev_ishole) {
4817                         if (lastlog == 0)
4818                                 lastlog = c;
4819                         continue;
4820                 }
4821 
4822                 lastlog = 0;
4823         }
4824         if (children != (lastlog != 0 ? lastlog : rvd->vdev_children))
4825                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4826 
4827         /* next, ensure no spare or cache devices are part of the split */
4828         if (nvlist_lookup_nvlist(nvl, ZPOOL_CONFIG_SPARES, &tmp) == 0 ||
4829             nvlist_lookup_nvlist(nvl, ZPOOL_CONFIG_L2CACHE, &tmp) == 0)
4830                 return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4831 
4832         vml = kmem_zalloc(children * sizeof (vdev_t *), KM_SLEEP);
4833         glist = kmem_zalloc(children * sizeof (uint64_t), KM_SLEEP);
4834 
4835         /* then, loop over each vdev and validate it */
4836         for (c = 0; c < children; c++) {
4837                 uint64_t is_hole = 0;
4838 
4839                 (void) nvlist_lookup_uint64(child[c], ZPOOL_CONFIG_IS_HOLE,
4840                     &is_hole);
4841 
4842                 if (is_hole != 0) {
4843                         if (spa->spa_root_vdev->vdev_child[c]->vdev_ishole ||
4844                             spa->spa_root_vdev->vdev_child[c]->vdev_islog) {
4845                                 continue;
4846                         } else {
4847                                 error = SET_ERROR(EINVAL);
4848                                 break;
4849                         }
4850                 }
4851 
4852                 /* which disk is going to be split? */
4853                 if (nvlist_lookup_uint64(child[c], ZPOOL_CONFIG_GUID,
4854                     &glist[c]) != 0) {
4855                         error = SET_ERROR(EINVAL);
4856                         break;
4857                 }
4858 
4859                 /* look it up in the spa */
4860                 vml[c] = spa_lookup_by_guid(spa, glist[c], B_FALSE);
4861                 if (vml[c] == NULL) {
4862                         error = SET_ERROR(ENODEV);
4863                         break;
4864                 }
4865 
4866                 /* make sure there's nothing stopping the split */
4867                 if (vml[c]->vdev_parent->vdev_ops != &vdev_mirror_ops ||
4868                     vml[c]->vdev_islog ||
4869                     vml[c]->vdev_ishole ||
4870                     vml[c]->vdev_isspare ||
4871                     vml[c]->vdev_isl2cache ||
4872                     !vdev_writeable(vml[c]) ||
4873                     vml[c]->vdev_children != 0 ||
4874                     vml[c]->vdev_state != VDEV_STATE_HEALTHY ||
4875                     c != spa->spa_root_vdev->vdev_child[c]->vdev_id) {
4876                         error = SET_ERROR(EINVAL);
4877                         break;
4878                 }
4879 
4880                 if (vdev_dtl_required(vml[c])) {
4881                         error = SET_ERROR(EBUSY);
4882                         break;
4883                 }
4884 
4885                 /* we need certain info from the top level */
4886                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_METASLAB_ARRAY,
4887                     vml[c]->vdev_top->vdev_ms_array) == 0);
4888                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_METASLAB_SHIFT,
4889                     vml[c]->vdev_top->vdev_ms_shift) == 0);
4890                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_ASIZE,
4891                     vml[c]->vdev_top->vdev_asize) == 0);
4892                 VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_ASHIFT,
4893                     vml[c]->vdev_top->vdev_ashift) == 0);
4894         }
4895 
4896         if (error != 0) {
4897                 kmem_free(vml, children * sizeof (vdev_t *));
4898                 kmem_free(glist, children * sizeof (uint64_t));
4899                 return (spa_vdev_exit(spa, NULL, txg, error));
4900         }
4901 
4902         /* stop writers from using the disks */
4903         for (c = 0; c < children; c++) {
4904                 if (vml[c] != NULL)
4905                         vml[c]->vdev_offline = B_TRUE;
4906         }
4907         vdev_reopen(spa->spa_root_vdev);
4908 
4909         /*
4910          * Temporarily record the splitting vdevs in the spa config.  This
4911          * will disappear once the config is regenerated.
4912          */
4913         VERIFY(nvlist_alloc(&nvl, NV_UNIQUE_NAME, KM_SLEEP) == 0);
4914         VERIFY(nvlist_add_uint64_array(nvl, ZPOOL_CONFIG_SPLIT_LIST,
4915             glist, children) == 0);
4916         kmem_free(glist, children * sizeof (uint64_t));
4917 
4918         mutex_enter(&spa->spa_props_lock);
4919         VERIFY(nvlist_add_nvlist(spa->spa_config, ZPOOL_CONFIG_SPLIT,
4920             nvl) == 0);
4921         mutex_exit(&spa->spa_props_lock);
4922         spa->spa_config_splitting = nvl;
4923         vdev_config_dirty(spa->spa_root_vdev);
4924 
4925         /* configure and create the new pool */
4926         VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME, newname) == 0);
4927         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,
4928             exp ? POOL_STATE_EXPORTED : POOL_STATE_ACTIVE) == 0);
4929         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_VERSION,
4930             spa_version(spa)) == 0);
4931         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG,
4932             spa->spa_config_txg) == 0);
4933         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID,
4934             spa_generate_guid(NULL)) == 0);
4935         (void) nvlist_lookup_string(props,
4936             zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
4937 
4938         /* add the new pool to the namespace */
4939         newspa = spa_add(newname, config, altroot);
4940         newspa->spa_config_txg = spa->spa_config_txg;
4941         spa_set_log_state(newspa, SPA_LOG_CLEAR);
4942 
4943         /* release the spa config lock, retaining the namespace lock */
4944         spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
4945 
4946         if (zio_injection_enabled)
4947                 zio_handle_panic_injection(spa, FTAG, 1);
4948 
4949         spa_activate(newspa, spa_mode_global);
4950         spa_async_suspend(newspa);
4951 
4952         /* create the new pool from the disks of the original pool */
4953         error = spa_load(newspa, SPA_LOAD_IMPORT, SPA_IMPORT_ASSEMBLE, B_TRUE);
4954         if (error)
4955                 goto out;
4956 
4957         /* if that worked, generate a real config for the new pool */
4958         if (newspa->spa_root_vdev != NULL) {
4959                 VERIFY(nvlist_alloc(&newspa->spa_config_splitting,
4960                     NV_UNIQUE_NAME, KM_SLEEP) == 0);
4961                 VERIFY(nvlist_add_uint64(newspa->spa_config_splitting,
4962                     ZPOOL_CONFIG_SPLIT_GUID, spa_guid(spa)) == 0);
4963                 spa_config_set(newspa, spa_config_generate(newspa, NULL, -1ULL,
4964                     B_TRUE));
4965         }
4966 
4967         /* set the props */
4968         if (props != NULL) {
4969                 spa_configfile_set(newspa, props, B_FALSE);
4970                 error = spa_prop_set(newspa, props);
4971                 if (error)
4972                         goto out;
4973         }
4974 
4975         /* flush everything */
4976         txg = spa_vdev_config_enter(newspa);
4977         vdev_config_dirty(newspa->spa_root_vdev);
4978         (void) spa_vdev_config_exit(newspa, NULL, txg, 0, FTAG);
4979 
4980         if (zio_injection_enabled)
4981                 zio_handle_panic_injection(spa, FTAG, 2);
4982 
4983         spa_async_resume(newspa);
4984 
4985         /* finally, update the original pool's config */
4986         txg = spa_vdev_config_enter(spa);
4987         tx = dmu_tx_create_dd(spa_get_dsl(spa)->dp_mos_dir);
4988         error = dmu_tx_assign(tx, TXG_WAIT);
4989         if (error != 0)
4990                 dmu_tx_abort(tx);
4991         for (c = 0; c < children; c++) {
4992                 if (vml[c] != NULL) {
4993                         vdev_split(vml[c]);
4994                         if (error == 0)
4995                                 spa_history_log_internal(spa, "detach", tx,
4996                                     "vdev=%s", vml[c]->vdev_path);
4997                         vdev_free(vml[c]);
4998                 }
4999         }
5000         vdev_config_dirty(spa->spa_root_vdev);
5001         spa->spa_config_splitting = NULL;
5002         nvlist_free(nvl);
5003         if (error == 0)
5004                 dmu_tx_commit(tx);
5005         (void) spa_vdev_exit(spa, NULL, txg, 0);
5006 
5007         if (zio_injection_enabled)
5008                 zio_handle_panic_injection(spa, FTAG, 3);
5009 
5010         /* split is complete; log a history record */
5011         spa_history_log_internal(newspa, "split", NULL,
5012             "from pool %s", spa_name(spa));
5013 
5014         kmem_free(vml, children * sizeof (vdev_t *));
5015 
5016         /* if we're not going to mount the filesystems in userland, export */
5017         if (exp)
5018                 error = spa_export_common(newname, POOL_STATE_EXPORTED, NULL,
5019                     B_FALSE, B_FALSE);
5020 
5021         return (error);
5022 
5023 out:
5024         spa_unload(newspa);
5025         spa_deactivate(newspa);
5026         spa_remove(newspa);
5027 
5028         txg = spa_vdev_config_enter(spa);
5029 
5030         /* re-online all offlined disks */
5031         for (c = 0; c < children; c++) {
5032                 if (vml[c] != NULL)
5033                         vml[c]->vdev_offline = B_FALSE;
5034         }
5035         vdev_reopen(spa->spa_root_vdev);
5036 
5037         nvlist_free(spa->spa_config_splitting);
5038         spa->spa_config_splitting = NULL;
5039         (void) spa_vdev_exit(spa, NULL, txg, error);
5040 
5041         kmem_free(vml, children * sizeof (vdev_t *));
5042         return (error);
5043 }
5044 
5045 static nvlist_t *
5046 spa_nvlist_lookup_by_guid(nvlist_t **nvpp, int count, uint64_t target_guid)
5047 {
5048         for (int i = 0; i < count; i++) {
5049                 uint64_t guid;
5050 
5051                 VERIFY(nvlist_lookup_uint64(nvpp[i], ZPOOL_CONFIG_GUID,
5052                     &guid) == 0);
5053 
5054                 if (guid == target_guid)
5055                         return (nvpp[i]);
5056         }
5057 
5058         return (NULL);
5059 }
5060 
5061 static void
5062 spa_vdev_remove_aux(nvlist_t *config, char *name, nvlist_t **dev, int count,
5063         nvlist_t *dev_to_remove)
5064 {
5065         nvlist_t **newdev = NULL;
5066 
5067         if (count > 1)
5068                 newdev = kmem_alloc((count - 1) * sizeof (void *), KM_SLEEP);
5069 
5070         for (int i = 0, j = 0; i < count; i++) {
5071                 if (dev[i] == dev_to_remove)
5072                         continue;
5073                 VERIFY(nvlist_dup(dev[i], &newdev[j++], KM_SLEEP) == 0);
5074         }
5075 
5076         VERIFY(nvlist_remove(config, name, DATA_TYPE_NVLIST_ARRAY) == 0);
5077         VERIFY(nvlist_add_nvlist_array(config, name, newdev, count - 1) == 0);
5078 
5079         for (int i = 0; i < count - 1; i++)
5080                 nvlist_free(newdev[i]);
5081 
5082         if (count > 1)
5083                 kmem_free(newdev, (count - 1) * sizeof (void *));
5084 }
5085 
5086 /*
5087  * Evacuate the device.
5088  */
5089 static int
5090 spa_vdev_remove_evacuate(spa_t *spa, vdev_t *vd)
5091 {
5092         uint64_t txg;
5093         int error = 0;
5094 
5095         ASSERT(MUTEX_HELD(&spa_namespace_lock));
5096         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
5097         ASSERT(vd == vd->vdev_top);
5098 
5099         /*
5100          * Evacuate the device.  We don't hold the config lock as writer
5101          * since we need to do I/O but we do keep the
5102          * spa_namespace_lock held.  Once this completes the device
5103          * should no longer have any blocks allocated on it.
5104          */
5105         if (vd->vdev_islog) {
5106                 if (vd->vdev_stat.vs_alloc != 0)
5107                         error = spa_offline_log(spa);
5108         } else {
5109                 error = SET_ERROR(ENOTSUP);
5110         }
5111 
5112         if (error)
5113                 return (error);
5114 
5115         /*
5116          * The evacuation succeeded.  Remove any remaining MOS metadata
5117          * associated with this vdev, and wait for these changes to sync.
5118          */
5119         ASSERT0(vd->vdev_stat.vs_alloc);
5120         txg = spa_vdev_config_enter(spa);
5121         vd->vdev_removing = B_TRUE;
5122         vdev_dirty(vd, 0, NULL, txg);
5123         vdev_config_dirty(vd);
5124         spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
5125 
5126         return (0);
5127 }
5128 
5129 /*
5130  * Complete the removal by cleaning up the namespace.
5131  */
5132 static void
5133 spa_vdev_remove_from_namespace(spa_t *spa, vdev_t *vd)
5134 {
5135         vdev_t *rvd = spa->spa_root_vdev;
5136         uint64_t id = vd->vdev_id;
5137         boolean_t last_vdev = (id == (rvd->vdev_children - 1));
5138 
5139         ASSERT(MUTEX_HELD(&spa_namespace_lock));
5140         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
5141         ASSERT(vd == vd->vdev_top);
5142 
5143         /*
5144          * Only remove any devices which are empty.
5145          */
5146         if (vd->vdev_stat.vs_alloc != 0)
5147                 return;
5148 
5149         (void) vdev_label_init(vd, 0, VDEV_LABEL_REMOVE);
5150 
5151         if (list_link_active(&vd->vdev_state_dirty_node))
5152                 vdev_state_clean(vd);
5153         if (list_link_active(&vd->vdev_config_dirty_node))
5154                 vdev_config_clean(vd);
5155 
5156         vdev_free(vd);
5157 
5158         if (last_vdev) {
5159                 vdev_compact_children(rvd);
5160         } else {
5161                 vd = vdev_alloc_common(spa, id, 0, &vdev_hole_ops);
5162                 vdev_add_child(rvd, vd);
5163         }
5164         vdev_config_dirty(rvd);
5165 
5166         /*
5167          * Reassess the health of our root vdev.
5168          */
5169         vdev_reopen(rvd);
5170 }
5171 
5172 /*
5173  * Remove a device from the pool -
5174  *
5175  * Removing a device from the vdev namespace requires several steps
5176  * and can take a significant amount of time.  As a result we use
5177  * the spa_vdev_config_[enter/exit] functions which allow us to
5178  * grab and release the spa_config_lock while still holding the namespace
5179  * lock.  During each step the configuration is synced out.
5180  *
5181  * Currently, this supports removing only hot spares, slogs, and level 2 ARC
5182  * devices.
5183  */
5184 int
5185 spa_vdev_remove(spa_t *spa, uint64_t guid, boolean_t unspare)
5186 {
5187         vdev_t *vd;
5188         metaslab_group_t *mg;
5189         nvlist_t **spares, **l2cache, *nv;
5190         uint64_t txg = 0;
5191         uint_t nspares, nl2cache;
5192         int error = 0;
5193         boolean_t locked = MUTEX_HELD(&spa_namespace_lock);
5194 
5195         ASSERT(spa_writeable(spa));
5196 
5197         if (!locked)
5198                 txg = spa_vdev_enter(spa);
5199 
5200         vd = spa_lookup_by_guid(spa, guid, B_FALSE);
5201 
5202         if (spa->spa_spares.sav_vdevs != NULL &&
5203             nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
5204             ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0 &&
5205             (nv = spa_nvlist_lookup_by_guid(spares, nspares, guid)) != NULL) {
5206                 /*
5207                  * Only remove the hot spare if it's not currently in use
5208                  * in this pool.
5209                  */
5210                 if (vd == NULL || unspare) {
5211                         spa_vdev_remove_aux(spa->spa_spares.sav_config,
5212                             ZPOOL_CONFIG_SPARES, spares, nspares, nv);
5213                         spa_load_spares(spa);
5214                         spa->spa_spares.sav_sync = B_TRUE;
5215                 } else {
5216                         error = SET_ERROR(EBUSY);
5217                 }
5218         } else if (spa->spa_l2cache.sav_vdevs != NULL &&
5219             nvlist_lookup_nvlist_array(spa->spa_l2cache.sav_config,
5220             ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0 &&
5221             (nv = spa_nvlist_lookup_by_guid(l2cache, nl2cache, guid)) != NULL) {
5222                 /*
5223                  * Cache devices can always be removed.
5224                  */
5225                 spa_vdev_remove_aux(spa->spa_l2cache.sav_config,
5226                     ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache, nv);
5227                 spa_load_l2cache(spa);
5228                 spa->spa_l2cache.sav_sync = B_TRUE;
5229         } else if (vd != NULL && vd->vdev_islog) {
5230                 ASSERT(!locked);
5231                 ASSERT(vd == vd->vdev_top);
5232 
5233                 /*
5234                  * XXX - Once we have bp-rewrite this should
5235                  * become the common case.
5236                  */
5237 
5238                 mg = vd->vdev_mg;
5239 
5240                 /*
5241                  * Stop allocating from this vdev.
5242                  */
5243                 metaslab_group_passivate(mg);
5244 
5245                 /*
5246                  * Wait for the youngest allocations and frees to sync,
5247                  * and then wait for the deferral of those frees to finish.
5248                  */
5249                 spa_vdev_config_exit(spa, NULL,
5250                     txg + TXG_CONCURRENT_STATES + TXG_DEFER_SIZE, 0, FTAG);
5251 
5252                 /*
5253                  * Attempt to evacuate the vdev.
5254                  */
5255                 error = spa_vdev_remove_evacuate(spa, vd);
5256 
5257                 txg = spa_vdev_config_enter(spa);
5258 
5259                 /*
5260                  * If we couldn't evacuate the vdev, unwind.
5261                  */
5262                 if (error) {
5263                         metaslab_group_activate(mg);
5264                         return (spa_vdev_exit(spa, NULL, txg, error));
5265                 }
5266 
5267                 /*
5268                  * Clean up the vdev namespace.
5269                  */
5270                 spa_vdev_remove_from_namespace(spa, vd);
5271 
5272         } else if (vd != NULL) {
5273                 /*
5274                  * Normal vdevs cannot be removed (yet).
5275                  */
5276                 error = SET_ERROR(ENOTSUP);
5277         } else {
5278                 /*
5279                  * There is no vdev of any kind with the specified guid.
5280                  */
5281                 error = SET_ERROR(ENOENT);
5282         }
5283 
5284         if (!locked)
5285                 return (spa_vdev_exit(spa, NULL, txg, error));
5286 
5287         return (error);
5288 }
5289 
5290 /*
5291  * Find any device that's done replacing, or a vdev marked 'unspare' that's
5292  * currently spared, so we can detach it.
5293  */
5294 static vdev_t *
5295 spa_vdev_resilver_done_hunt(vdev_t *vd)
5296 {
5297         vdev_t *newvd, *oldvd;
5298 
5299         for (int c = 0; c < vd->vdev_children; c++) {
5300                 oldvd = spa_vdev_resilver_done_hunt(vd->vdev_child[c]);
5301                 if (oldvd != NULL)
5302                         return (oldvd);
5303         }
5304 
5305         /*
5306          * Check for a completed replacement.  We always consider the first
5307          * vdev in the list to be the oldest vdev, and the last one to be
5308          * the newest (see spa_vdev_attach() for how that works).  In
5309          * the case where the newest vdev is faulted, we will not automatically
5310          * remove it after a resilver completes.  This is OK as it will require
5311          * user intervention to determine which disk the admin wishes to keep.
5312          */
5313         if (vd->vdev_ops == &vdev_replacing_ops) {
5314                 ASSERT(vd->vdev_children > 1);
5315 
5316                 newvd = vd->vdev_child[vd->vdev_children - 1];
5317                 oldvd = vd->vdev_child[0];
5318 
5319                 if (vdev_dtl_empty(newvd, DTL_MISSING) &&
5320                     vdev_dtl_empty(newvd, DTL_OUTAGE) &&
5321                     !vdev_dtl_required(oldvd))
5322                         return (oldvd);
5323         }
5324 
5325         /*
5326          * Check for a completed resilver with the 'unspare' flag set.
5327          */
5328         if (vd->vdev_ops == &vdev_spare_ops) {
5329                 vdev_t *first = vd->vdev_child[0];
5330                 vdev_t *last = vd->vdev_child[vd->vdev_children - 1];
5331 
5332                 if (last->vdev_unspare) {
5333                         oldvd = first;
5334                         newvd = last;
5335                 } else if (first->vdev_unspare) {
5336                         oldvd = last;
5337                         newvd = first;
5338                 } else {
5339                         oldvd = NULL;
5340                 }
5341 
5342                 if (oldvd != NULL &&
5343                     vdev_dtl_empty(newvd, DTL_MISSING) &&
5344                     vdev_dtl_empty(newvd, DTL_OUTAGE) &&
5345                     !vdev_dtl_required(oldvd))
5346                         return (oldvd);
5347 
5348                 /*
5349                  * If there are more than two spares attached to a disk,
5350                  * and those spares are not required, then we want to
5351                  * attempt to free them up now so that they can be used
5352                  * by other pools.  Once we're back down to a single
5353                  * disk+spare, we stop removing them.
5354                  */
5355                 if (vd->vdev_children > 2) {
5356                         newvd = vd->vdev_child[1];
5357 
5358                         if (newvd->vdev_isspare && last->vdev_isspare &&
5359                             vdev_dtl_empty(last, DTL_MISSING) &&
5360                             vdev_dtl_empty(last, DTL_OUTAGE) &&
5361                             !vdev_dtl_required(newvd))
5362                                 return (newvd);
5363                 }
5364         }
5365 
5366         return (NULL);
5367 }
5368 
5369 static void
5370 spa_vdev_resilver_done(spa_t *spa)
5371 {
5372         vdev_t *vd, *pvd, *ppvd;
5373         uint64_t guid, sguid, pguid, ppguid;
5374 
5375         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
5376 
5377         while ((vd = spa_vdev_resilver_done_hunt(spa->spa_root_vdev)) != NULL) {
5378                 pvd = vd->vdev_parent;
5379                 ppvd = pvd->vdev_parent;
5380                 guid = vd->vdev_guid;
5381                 pguid = pvd->vdev_guid;
5382                 ppguid = ppvd->vdev_guid;
5383                 sguid = 0;
5384                 /*
5385                  * If we have just finished replacing a hot spared device, then
5386                  * we need to detach the parent's first child (the original hot
5387                  * spare) as well.
5388                  */
5389                 if (ppvd->vdev_ops == &vdev_spare_ops && pvd->vdev_id == 0 &&
5390                     ppvd->vdev_children == 2) {
5391                         ASSERT(pvd->vdev_ops == &vdev_replacing_ops);
5392                         sguid = ppvd->vdev_child[1]->vdev_guid;
5393                 }
5394                 spa_config_exit(spa, SCL_ALL, FTAG);
5395                 if (spa_vdev_detach(spa, guid, pguid, B_TRUE) != 0)
5396                         return;
5397                 if (sguid && spa_vdev_detach(spa, sguid, ppguid, B_TRUE) != 0)
5398                         return;
5399                 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
5400         }
5401 
5402         spa_config_exit(spa, SCL_ALL, FTAG);
5403 }
5404 
5405 /*
5406  * Update the stored path or FRU for this vdev.
5407  */
5408 int
5409 spa_vdev_set_common(spa_t *spa, uint64_t guid, const char *value,
5410     boolean_t ispath)
5411 {
5412         vdev_t *vd;
5413         boolean_t sync = B_FALSE;
5414 
5415         ASSERT(spa_writeable(spa));
5416 
5417         spa_vdev_state_enter(spa, SCL_ALL);
5418 
5419         if ((vd = spa_lookup_by_guid(spa, guid, B_TRUE)) == NULL)
5420                 return (spa_vdev_state_exit(spa, NULL, ENOENT));
5421 
5422         if (!vd->vdev_ops->vdev_op_leaf)
5423                 return (spa_vdev_state_exit(spa, NULL, ENOTSUP));
5424 
5425         if (ispath) {
5426                 if (strcmp(value, vd->vdev_path) != 0) {
5427                         spa_strfree(vd->vdev_path);
5428                         vd->vdev_path = spa_strdup(value);
5429                         sync = B_TRUE;
5430                 }
5431         } else {
5432                 if (vd->vdev_fru == NULL) {
5433                         vd->vdev_fru = spa_strdup(value);
5434                         sync = B_TRUE;
5435                 } else if (strcmp(value, vd->vdev_fru) != 0) {
5436                         spa_strfree(vd->vdev_fru);
5437                         vd->vdev_fru = spa_strdup(value);
5438                         sync = B_TRUE;
5439                 }
5440         }
5441 
5442         return (spa_vdev_state_exit(spa, sync ? vd : NULL, 0));
5443 }
5444 
5445 int
5446 spa_vdev_setpath(spa_t *spa, uint64_t guid, const char *newpath)
5447 {
5448         return (spa_vdev_set_common(spa, guid, newpath, B_TRUE));
5449 }
5450 
5451 int
5452 spa_vdev_setfru(spa_t *spa, uint64_t guid, const char *newfru)
5453 {
5454         return (spa_vdev_set_common(spa, guid, newfru, B_FALSE));
5455 }
5456 
5457 /*
5458  * ==========================================================================
5459  * SPA Scanning
5460  * ==========================================================================
5461  */
5462 
5463 int
5464 spa_scan_stop(spa_t *spa)
5465 {
5466         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
5467         if (dsl_scan_resilvering(spa->spa_dsl_pool))
5468                 return (SET_ERROR(EBUSY));
5469         return (dsl_scan_cancel(spa->spa_dsl_pool));
5470 }
5471 
5472 int
5473 spa_scan(spa_t *spa, pool_scan_func_t func)
5474 {
5475         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
5476 
5477         if (func >= POOL_SCAN_FUNCS || func == POOL_SCAN_NONE)
5478                 return (SET_ERROR(ENOTSUP));
5479 
5480         /*
5481          * If a resilver was requested, but there is no DTL on a
5482          * writeable leaf device, we have nothing to do.
5483          */
5484         if (func == POOL_SCAN_RESILVER &&
5485             !vdev_resilver_needed(spa->spa_root_vdev, NULL, NULL)) {
5486                 spa_async_request(spa, SPA_ASYNC_RESILVER_DONE);
5487                 return (0);
5488         }
5489 
5490         return (dsl_scan(spa->spa_dsl_pool, func));
5491 }
5492 
5493 /*
5494  * ==========================================================================
5495  * SPA async task processing
5496  * ==========================================================================
5497  */
5498 
5499 static void
5500 spa_async_remove(spa_t *spa, vdev_t *vd)
5501 {
5502         if (vd->vdev_remove_wanted) {
5503                 vd->vdev_remove_wanted = B_FALSE;
5504                 vd->vdev_delayed_close = B_FALSE;
5505                 vdev_set_state(vd, B_FALSE, VDEV_STATE_REMOVED, VDEV_AUX_NONE);
5506 
5507                 /*
5508                  * We want to clear the stats, but we don't want to do a full
5509                  * vdev_clear() as that will cause us to throw away
5510                  * degraded/faulted state as well as attempt to reopen the
5511                  * device, all of which is a waste.
5512                  */
5513                 vd->vdev_stat.vs_read_errors = 0;
5514                 vd->vdev_stat.vs_write_errors = 0;
5515                 vd->vdev_stat.vs_checksum_errors = 0;
5516 
5517                 vdev_state_dirty(vd->vdev_top);
5518         }
5519 
5520         for (int c = 0; c < vd->vdev_children; c++)
5521                 spa_async_remove(spa, vd->vdev_child[c]);
5522 }
5523 
5524 static void
5525 spa_async_probe(spa_t *spa, vdev_t *vd)
5526 {
5527         if (vd->vdev_probe_wanted) {
5528                 vd->vdev_probe_wanted = B_FALSE;
5529                 vdev_reopen(vd);        /* vdev_open() does the actual probe */
5530         }
5531 
5532         for (int c = 0; c < vd->vdev_children; c++)
5533                 spa_async_probe(spa, vd->vdev_child[c]);
5534 }
5535 
5536 static void
5537 spa_async_autoexpand(spa_t *spa, vdev_t *vd)
5538 {
5539         sysevent_id_t eid;
5540         nvlist_t *attr;
5541         char *physpath;
5542 
5543         if (!spa->spa_autoexpand)
5544                 return;
5545 
5546         for (int c = 0; c < vd->vdev_children; c++) {
5547                 vdev_t *cvd = vd->vdev_child[c];
5548                 spa_async_autoexpand(spa, cvd);
5549         }
5550 
5551         if (!vd->vdev_ops->vdev_op_leaf || vd->vdev_physpath == NULL)
5552                 return;
5553 
5554         physpath = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
5555         (void) snprintf(physpath, MAXPATHLEN, "/devices%s", vd->vdev_physpath);
5556 
5557         VERIFY(nvlist_alloc(&attr, NV_UNIQUE_NAME, KM_SLEEP) == 0);
5558         VERIFY(nvlist_add_string(attr, DEV_PHYS_PATH, physpath) == 0);
5559 
5560         (void) ddi_log_sysevent(zfs_dip, SUNW_VENDOR, EC_DEV_STATUS,
5561             ESC_DEV_DLE, attr, &eid, DDI_SLEEP);
5562 
5563         nvlist_free(attr);
5564         kmem_free(physpath, MAXPATHLEN);
5565 }
5566 
5567 static void
5568 spa_async_thread(spa_t *spa)
5569 {
5570         int tasks;
5571 
5572         ASSERT(spa->spa_sync_on);
5573 
5574         mutex_enter(&spa->spa_async_lock);
5575         tasks = spa->spa_async_tasks;
5576         spa->spa_async_tasks = 0;
5577         mutex_exit(&spa->spa_async_lock);
5578 
5579         /*
5580          * See if the config needs to be updated.
5581          */
5582         if (tasks & SPA_ASYNC_CONFIG_UPDATE) {
5583                 uint64_t old_space, new_space;
5584 
5585                 mutex_enter(&spa_namespace_lock);
5586                 old_space = metaslab_class_get_space(spa_normal_class(spa));
5587                 spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
5588                 new_space = metaslab_class_get_space(spa_normal_class(spa));
5589                 mutex_exit(&spa_namespace_lock);
5590 
5591                 /*
5592                  * If the pool grew as a result of the config update,
5593                  * then log an internal history event.
5594                  */
5595                 if (new_space != old_space) {
5596                         spa_history_log_internal(spa, "vdev online", NULL,
5597                             "pool '%s' size: %llu(+%llu)",
5598                             spa_name(spa), new_space, new_space - old_space);
5599                 }
5600         }
5601 
5602         /*
5603          * See if any devices need to be marked REMOVED.
5604          */
5605         if (tasks & SPA_ASYNC_REMOVE) {
5606                 spa_vdev_state_enter(spa, SCL_NONE);
5607                 spa_async_remove(spa, spa->spa_root_vdev);
5608                 for (int i = 0; i < spa->spa_l2cache.sav_count; i++)
5609                         spa_async_remove(spa, spa->spa_l2cache.sav_vdevs[i]);
5610                 for (int i = 0; i < spa->spa_spares.sav_count; i++)
5611                         spa_async_remove(spa, spa->spa_spares.sav_vdevs[i]);
5612                 (void) spa_vdev_state_exit(spa, NULL, 0);
5613         }
5614 
5615         if ((tasks & SPA_ASYNC_AUTOEXPAND) && !spa_suspended(spa)) {
5616                 spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
5617                 spa_async_autoexpand(spa, spa->spa_root_vdev);
5618                 spa_config_exit(spa, SCL_CONFIG, FTAG);
5619         }
5620 
5621         /*
5622          * See if any devices need to be probed.
5623          */
5624         if (tasks & SPA_ASYNC_PROBE) {
5625                 spa_vdev_state_enter(spa, SCL_NONE);
5626                 spa_async_probe(spa, spa->spa_root_vdev);
5627                 (void) spa_vdev_state_exit(spa, NULL, 0);
5628         }
5629 
5630         /*
5631          * If any devices are done replacing, detach them.
5632          */
5633         if (tasks & SPA_ASYNC_RESILVER_DONE)
5634                 spa_vdev_resilver_done(spa);
5635 
5636         /*
5637          * Kick off a resilver.
5638          */
5639         if (tasks & SPA_ASYNC_RESILVER)
5640                 dsl_resilver_restart(spa->spa_dsl_pool, 0);
5641 
5642         /*
5643          * Let the world know that we're done.
5644          */
5645         mutex_enter(&spa->spa_async_lock);
5646         spa->spa_async_thread = NULL;
5647         cv_broadcast(&spa->spa_async_cv);
5648         mutex_exit(&spa->spa_async_lock);
5649         thread_exit();
5650 }
5651 
5652 void
5653 spa_async_suspend(spa_t *spa)
5654 {
5655         mutex_enter(&spa->spa_async_lock);
5656         spa->spa_async_suspended++;
5657         while (spa->spa_async_thread != NULL)
5658                 cv_wait(&spa->spa_async_cv, &spa->spa_async_lock);
5659         mutex_exit(&spa->spa_async_lock);
5660 }
5661 
5662 void
5663 spa_async_resume(spa_t *spa)
5664 {
5665         mutex_enter(&spa->spa_async_lock);
5666         ASSERT(spa->spa_async_suspended != 0);
5667         spa->spa_async_suspended--;
5668         mutex_exit(&spa->spa_async_lock);
5669 }
5670 
5671 static boolean_t
5672 spa_async_tasks_pending(spa_t *spa)
5673 {
5674         uint_t non_config_tasks;
5675         uint_t config_task;
5676         boolean_t config_task_suspended;
5677 
5678         non_config_tasks = spa->spa_async_tasks & ~SPA_ASYNC_CONFIG_UPDATE;
5679         config_task = spa->spa_async_tasks & SPA_ASYNC_CONFIG_UPDATE;
5680         if (spa->spa_ccw_fail_time == 0) {
5681                 config_task_suspended = B_FALSE;
5682         } else {
5683                 config_task_suspended =
5684                     (gethrtime() - spa->spa_ccw_fail_time) <
5685                     (zfs_ccw_retry_interval * NANOSEC);
5686         }
5687 
5688         return (non_config_tasks || (config_task && !config_task_suspended));
5689 }
5690 
5691 static void
5692 spa_async_dispatch(spa_t *spa)
5693 {
5694         mutex_enter(&spa->spa_async_lock);
5695         if (spa_async_tasks_pending(spa) &&
5696             !spa->spa_async_suspended &&
5697             spa->spa_async_thread == NULL &&
5698             rootdir != NULL)
5699                 spa->spa_async_thread = thread_create(NULL, 0,
5700                     spa_async_thread, spa, 0, &p0, TS_RUN, maxclsyspri);
5701         mutex_exit(&spa->spa_async_lock);
5702 }
5703 
5704 void
5705 spa_async_request(spa_t *spa, int task)
5706 {
5707         zfs_dbgmsg("spa=%s async request task=%u", spa->spa_name, task);
5708         mutex_enter(&spa->spa_async_lock);
5709         spa->spa_async_tasks |= task;
5710         mutex_exit(&spa->spa_async_lock);
5711 }
5712 
5713 /*
5714  * ==========================================================================
5715  * SPA syncing routines
5716  * ==========================================================================
5717  */
5718 
5719 static int
5720 bpobj_enqueue_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
5721 {
5722         bpobj_t *bpo = arg;
5723         bpobj_enqueue(bpo, bp, tx);
5724         return (0);
5725 }
5726 
5727 static int
5728 spa_free_sync_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
5729 {
5730         zio_t *zio = arg;
5731 
5732         zio_nowait(zio_free_sync(zio, zio->io_spa, dmu_tx_get_txg(tx), bp,
5733             zio->io_flags));
5734         return (0);
5735 }
5736 
5737 static void
5738 spa_sync_nvlist(spa_t *spa, uint64_t obj, nvlist_t *nv, dmu_tx_t *tx)
5739 {
5740         char *packed = NULL;
5741         size_t bufsize;
5742         size_t nvsize = 0;
5743         dmu_buf_t *db;
5744 
5745         VERIFY(nvlist_size(nv, &nvsize, NV_ENCODE_XDR) == 0);
5746 
5747         /*
5748          * Write full (SPA_CONFIG_BLOCKSIZE) blocks of configuration
5749          * information.  This avoids the dbuf_will_dirty() path and
5750          * saves us a pre-read to get data we don't actually care about.
5751          */
5752         bufsize = P2ROUNDUP((uint64_t)nvsize, SPA_CONFIG_BLOCKSIZE);
5753         packed = kmem_alloc(bufsize, KM_SLEEP);
5754 
5755         VERIFY(nvlist_pack(nv, &packed, &nvsize, NV_ENCODE_XDR,
5756             KM_SLEEP) == 0);
5757         bzero(packed + nvsize, bufsize - nvsize);
5758 
5759         dmu_write(spa->spa_meta_objset, obj, 0, bufsize, packed, tx);
5760 
5761         kmem_free(packed, bufsize);
5762 
5763         VERIFY(0 == dmu_bonus_hold(spa->spa_meta_objset, obj, FTAG, &db));
5764         dmu_buf_will_dirty(db, tx);
5765         *(uint64_t *)db->db_data = nvsize;
5766         dmu_buf_rele(db, FTAG);
5767 }
5768 
5769 static void
5770 spa_sync_aux_dev(spa_t *spa, spa_aux_vdev_t *sav, dmu_tx_t *tx,
5771     const char *config, const char *entry)
5772 {
5773         nvlist_t *nvroot;
5774         nvlist_t **list;
5775         int i;
5776 
5777         if (!sav->sav_sync)
5778                 return;
5779 
5780         /*
5781          * Update the MOS nvlist describing the list of available devices.
5782          * spa_validate_aux() will have already made sure this nvlist is
5783          * valid and the vdevs are labeled appropriately.
5784          */
5785         if (sav->sav_object == 0) {
5786                 sav->sav_object = dmu_object_alloc(spa->spa_meta_objset,
5787                     DMU_OT_PACKED_NVLIST, 1 << 14, DMU_OT_PACKED_NVLIST_SIZE,
5788                     sizeof (uint64_t), tx);
5789                 VERIFY(zap_update(spa->spa_meta_objset,
5790                     DMU_POOL_DIRECTORY_OBJECT, entry, sizeof (uint64_t), 1,
5791                     &sav->sav_object, tx) == 0);
5792         }
5793 
5794         VERIFY(nvlist_alloc(&nvroot, NV_UNIQUE_NAME, KM_SLEEP) == 0);
5795         if (sav->sav_count == 0) {
5796                 VERIFY(nvlist_add_nvlist_array(nvroot, config, NULL, 0) == 0);
5797         } else {
5798                 list = kmem_alloc(sav->sav_count * sizeof (void *), KM_SLEEP);
5799                 for (i = 0; i < sav->sav_count; i++)
5800                         list[i] = vdev_config_generate(spa, sav->sav_vdevs[i],
5801                             B_FALSE, VDEV_CONFIG_L2CACHE);
5802                 VERIFY(nvlist_add_nvlist_array(nvroot, config, list,
5803                     sav->sav_count) == 0);
5804                 for (i = 0; i < sav->sav_count; i++)
5805                         nvlist_free(list[i]);
5806                 kmem_free(list, sav->sav_count * sizeof (void *));
5807         }
5808 
5809         spa_sync_nvlist(spa, sav->sav_object, nvroot, tx);
5810         nvlist_free(nvroot);
5811 
5812         sav->sav_sync = B_FALSE;
5813 }
5814 
5815 static void
5816 spa_sync_config_object(spa_t *spa, dmu_tx_t *tx)
5817 {
5818         nvlist_t *config;
5819 
5820         if (list_is_empty(&spa->spa_config_dirty_list))
5821                 return;
5822 
5823         spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
5824 
5825         config = spa_config_generate(spa, spa->spa_root_vdev,
5826             dmu_tx_get_txg(tx), B_FALSE);
5827 
5828         /*
5829          * If we're upgrading the spa version then make sure that
5830          * the config object gets updated with the correct version.
5831          */
5832         if (spa->spa_ubsync.ub_version < spa->spa_uberblock.ub_version)
5833                 fnvlist_add_uint64(config, ZPOOL_CONFIG_VERSION,
5834                     spa->spa_uberblock.ub_version);
5835 
5836         spa_config_exit(spa, SCL_STATE, FTAG);
5837 
5838         if (spa->spa_config_syncing)
5839                 nvlist_free(spa->spa_config_syncing);
5840         spa->spa_config_syncing = config;
5841 
5842         spa_sync_nvlist(spa, spa->spa_config_object, config, tx);
5843 }
5844 
5845 static void
5846 spa_sync_version(void *arg, dmu_tx_t *tx)
5847 {
5848         uint64_t *versionp = arg;
5849         uint64_t version = *versionp;
5850         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
5851 
5852         /*
5853          * Setting the version is special cased when first creating the pool.
5854          */
5855         ASSERT(tx->tx_txg != TXG_INITIAL);
5856 
5857         ASSERT(SPA_VERSION_IS_SUPPORTED(version));
5858         ASSERT(version >= spa_version(spa));
5859 
5860         spa->spa_uberblock.ub_version = version;
5861         vdev_config_dirty(spa->spa_root_vdev);
5862         spa_history_log_internal(spa, "set", tx, "version=%lld", version);
5863 }
5864 
5865 /*
5866  * Set zpool properties.
5867  */
5868 static void
5869 spa_sync_props(void *arg, dmu_tx_t *tx)
5870 {
5871         nvlist_t *nvp = arg;
5872         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
5873         objset_t *mos = spa->spa_meta_objset;
5874         nvpair_t *elem = NULL;
5875 
5876         mutex_enter(&spa->spa_props_lock);
5877 
5878         while ((elem = nvlist_next_nvpair(nvp, elem))) {
5879                 uint64_t intval;
5880                 char *strval, *fname;
5881                 zpool_prop_t prop;
5882                 const char *propname;
5883                 zprop_type_t proptype;
5884                 zfeature_info_t *feature;
5885 
5886                 switch (prop = zpool_name_to_prop(nvpair_name(elem))) {
5887                 case ZPROP_INVAL:
5888                         /*
5889                          * We checked this earlier in spa_prop_validate().
5890                          */
5891                         ASSERT(zpool_prop_feature(nvpair_name(elem)));
5892 
5893                         fname = strchr(nvpair_name(elem), '@') + 1;
5894                         VERIFY3U(0, ==, zfeature_lookup_name(fname, &feature));
5895 
5896                         spa_feature_enable(spa, feature, tx);
5897                         spa_history_log_internal(spa, "set", tx,
5898                             "%s=enabled", nvpair_name(elem));
5899                         break;
5900 
5901                 case ZPOOL_PROP_VERSION:
5902                         VERIFY(nvpair_value_uint64(elem, &intval) == 0);
5903                         /*
5904                          * The version is synced seperatly before other
5905                          * properties and should be correct by now.
5906                          */
5907                         ASSERT3U(spa_version(spa), >=, intval);
5908                         break;
5909 
5910                 case ZPOOL_PROP_ALTROOT:
5911                         /*
5912                          * 'altroot' is a non-persistent property. It should
5913                          * have been set temporarily at creation or import time.
5914                          */
5915                         ASSERT(spa->spa_root != NULL);
5916                         break;
5917 
5918                 case ZPOOL_PROP_READONLY:
5919                 case ZPOOL_PROP_CACHEFILE:
5920                         /*
5921                          * 'readonly' and 'cachefile' are also non-persisitent
5922                          * properties.
5923                          */
5924                         break;
5925                 case ZPOOL_PROP_COMMENT:
5926                         VERIFY(nvpair_value_string(elem, &strval) == 0);
5927                         if (spa->spa_comment != NULL)
5928                                 spa_strfree(spa->spa_comment);
5929                         spa->spa_comment = spa_strdup(strval);
5930                         /*
5931                          * We need to dirty the configuration on all the vdevs
5932                          * so that their labels get updated.  It's unnecessary
5933                          * to do this for pool creation since the vdev's
5934                          * configuratoin has already been dirtied.
5935                          */
5936                         if (tx->tx_txg != TXG_INITIAL)
5937                                 vdev_config_dirty(spa->spa_root_vdev);
5938                         spa_history_log_internal(spa, "set", tx,
5939                             "%s=%s", nvpair_name(elem), strval);
5940                         break;
5941                 default:
5942                         /*
5943                          * Set pool property values in the poolprops mos object.
5944                          */
5945                         if (spa->spa_pool_props_object == 0) {
5946                                 spa->spa_pool_props_object =
5947                                     zap_create_link(mos, DMU_OT_POOL_PROPS,
5948                                     DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_PROPS,
5949                                     tx);
5950                         }
5951 
5952                         /* normalize the property name */
5953                         propname = zpool_prop_to_name(prop);
5954                         proptype = zpool_prop_get_type(prop);
5955 
5956                         if (nvpair_type(elem) == DATA_TYPE_STRING) {
5957                                 ASSERT(proptype == PROP_TYPE_STRING);
5958                                 VERIFY(nvpair_value_string(elem, &strval) == 0);
5959                                 VERIFY(zap_update(mos,
5960                                     spa->spa_pool_props_object, propname,
5961                                     1, strlen(strval) + 1, strval, tx) == 0);
5962                                 spa_history_log_internal(spa, "set", tx,
5963                                     "%s=%s", nvpair_name(elem), strval);
5964                         } else if (nvpair_type(elem) == DATA_TYPE_UINT64) {
5965                                 VERIFY(nvpair_value_uint64(elem, &intval) == 0);
5966 
5967                                 if (proptype == PROP_TYPE_INDEX) {
5968                                         const char *unused;
5969                                         VERIFY(zpool_prop_index_to_string(
5970                                             prop, intval, &unused) == 0);
5971                                 }
5972                                 VERIFY(zap_update(mos,
5973                                     spa->spa_pool_props_object, propname,
5974                                     8, 1, &intval, tx) == 0);
5975                                 spa_history_log_internal(spa, "set", tx,
5976                                     "%s=%lld", nvpair_name(elem), intval);
5977                         } else {
5978                                 ASSERT(0); /* not allowed */
5979                         }
5980 
5981                         switch (prop) {
5982                         case ZPOOL_PROP_DELEGATION:
5983                                 spa->spa_delegation = intval;
5984                                 break;
5985                         case ZPOOL_PROP_BOOTFS:
5986                                 spa->spa_bootfs = intval;
5987                                 break;
5988                         case ZPOOL_PROP_FAILUREMODE:
5989                                 spa->spa_failmode = intval;
5990                                 break;
5991                         case ZPOOL_PROP_AUTOEXPAND:
5992                                 spa->spa_autoexpand = intval;
5993                                 if (tx->tx_txg != TXG_INITIAL)
5994                                         spa_async_request(spa,
5995                                             SPA_ASYNC_AUTOEXPAND);
5996                                 break;
5997                         case ZPOOL_PROP_DEDUPDITTO:
5998                                 spa->spa_dedup_ditto = intval;
5999                                 break;
6000                         default:
6001                                 break;
6002                         }
6003                 }
6004 
6005         }
6006 
6007         mutex_exit(&spa->spa_props_lock);
6008 }
6009 
6010 /*
6011  * Perform one-time upgrade on-disk changes.  spa_version() does not
6012  * reflect the new version this txg, so there must be no changes this
6013  * txg to anything that the upgrade code depends on after it executes.
6014  * Therefore this must be called after dsl_pool_sync() does the sync
6015  * tasks.
6016  */
6017 static void
6018 spa_sync_upgrades(spa_t *spa, dmu_tx_t *tx)
6019 {
6020         dsl_pool_t *dp = spa->spa_dsl_pool;
6021 
6022         ASSERT(spa->spa_sync_pass == 1);
6023 
6024         rrw_enter(&dp->dp_config_rwlock, RW_WRITER, FTAG);
6025 
6026         if (spa->spa_ubsync.ub_version < SPA_VERSION_ORIGIN &&
6027             spa->spa_uberblock.ub_version >= SPA_VERSION_ORIGIN) {
6028                 dsl_pool_create_origin(dp, tx);
6029 
6030                 /* Keeping the origin open increases spa_minref */
6031                 spa->spa_minref += 3;
6032         }
6033 
6034         if (spa->spa_ubsync.ub_version < SPA_VERSION_NEXT_CLONES &&
6035             spa->spa_uberblock.ub_version >= SPA_VERSION_NEXT_CLONES) {
6036                 dsl_pool_upgrade_clones(dp, tx);
6037         }
6038 
6039         if (spa->spa_ubsync.ub_version < SPA_VERSION_DIR_CLONES &&
6040             spa->spa_uberblock.ub_version >= SPA_VERSION_DIR_CLONES) {
6041                 dsl_pool_upgrade_dir_clones(dp, tx);
6042 
6043                 /* Keeping the freedir open increases spa_minref */
6044                 spa->spa_minref += 3;
6045         }
6046 
6047         if (spa->spa_ubsync.ub_version < SPA_VERSION_FEATURES &&
6048             spa->spa_uberblock.ub_version >= SPA_VERSION_FEATURES) {
6049                 spa_feature_create_zap_objects(spa, tx);
6050         }
6051         rrw_exit(&dp->dp_config_rwlock, FTAG);
6052 }
6053 
6054 /*
6055  * Sync the specified transaction group.  New blocks may be dirtied as
6056  * part of the process, so we iterate until it converges.
6057  */
6058 void
6059 spa_sync(spa_t *spa, uint64_t txg)
6060 {
6061         dsl_pool_t *dp = spa->spa_dsl_pool;
6062         objset_t *mos = spa->spa_meta_objset;
6063         bpobj_t *defer_bpo = &spa->spa_deferred_bpobj;
6064         bplist_t *free_bpl = &spa->spa_free_bplist[txg & TXG_MASK];
6065         vdev_t *rvd = spa->spa_root_vdev;
6066         vdev_t *vd;
6067         dmu_tx_t *tx;
6068         int error;
6069 
6070         VERIFY(spa_writeable(spa));
6071 
6072         /*
6073          * Lock out configuration changes.
6074          */
6075         spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
6076 
6077         spa->spa_syncing_txg = txg;
6078         spa->spa_sync_pass = 0;
6079 
6080         /*
6081          * If there are any pending vdev state changes, convert them
6082          * into config changes that go out with this transaction group.
6083          */
6084         spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
6085         while (list_head(&spa->spa_state_dirty_list) != NULL) {
6086                 /*
6087                  * We need the write lock here because, for aux vdevs,
6088                  * calling vdev_config_dirty() modifies sav_config.
6089                  * This is ugly and will become unnecessary when we
6090                  * eliminate the aux vdev wart by integrating all vdevs
6091                  * into the root vdev tree.
6092                  */
6093                 spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
6094                 spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_WRITER);
6095                 while ((vd = list_head(&spa->spa_state_dirty_list)) != NULL) {
6096                         vdev_state_clean(vd);
6097                         vdev_config_dirty(vd);
6098                 }
6099                 spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
6100                 spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
6101         }
6102         spa_config_exit(spa, SCL_STATE, FTAG);
6103 
6104         tx = dmu_tx_create_assigned(dp, txg);
6105 
6106         spa->spa_sync_starttime = gethrtime();
6107         VERIFY(cyclic_reprogram(spa->spa_deadman_cycid,
6108             spa->spa_sync_starttime + spa->spa_deadman_synctime));
6109 
6110         /*
6111          * If we are upgrading to SPA_VERSION_RAIDZ_DEFLATE this txg,
6112          * set spa_deflate if we have no raid-z vdevs.
6113          */
6114         if (spa->spa_ubsync.ub_version < SPA_VERSION_RAIDZ_DEFLATE &&
6115             spa->spa_uberblock.ub_version >= SPA_VERSION_RAIDZ_DEFLATE) {
6116                 int i;
6117 
6118                 for (i = 0; i < rvd->vdev_children; i++) {
6119                         vd = rvd->vdev_child[i];
6120                         if (vd->vdev_deflate_ratio != SPA_MINBLOCKSIZE)
6121                                 break;
6122                 }
6123                 if (i == rvd->vdev_children) {
6124                         spa->spa_deflate = TRUE;
6125                         VERIFY(0 == zap_add(spa->spa_meta_objset,
6126                             DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
6127                             sizeof (uint64_t), 1, &spa->spa_deflate, tx));
6128                 }
6129         }
6130 
6131         /*
6132          * If anything has changed in this txg, or if someone is waiting
6133          * for this txg to sync (eg, spa_vdev_remove()), push the
6134          * deferred frees from the previous txg.  If not, leave them
6135          * alone so that we don't generate work on an otherwise idle
6136          * system.
6137          */
6138         if (!txg_list_empty(&dp->dp_dirty_datasets, txg) ||
6139             !txg_list_empty(&dp->dp_dirty_dirs, txg) ||
6140             !txg_list_empty(&dp->dp_sync_tasks, txg) ||
6141             ((dsl_scan_active(dp->dp_scan) ||
6142             txg_sync_waiting(dp)) && !spa_shutting_down(spa))) {
6143                 zio_t *zio = zio_root(spa, NULL, NULL, 0);
6144                 VERIFY3U(bpobj_iterate(defer_bpo,
6145                     spa_free_sync_cb, zio, tx), ==, 0);
6146                 VERIFY0(zio_wait(zio));
6147         }
6148 
6149         /*
6150          * Iterate to convergence.
6151          */
6152         do {
6153                 int pass = ++spa->spa_sync_pass;
6154 
6155                 spa_sync_config_object(spa, tx);
6156                 spa_sync_aux_dev(spa, &spa->spa_spares, tx,
6157                     ZPOOL_CONFIG_SPARES, DMU_POOL_SPARES);
6158                 spa_sync_aux_dev(spa, &spa->spa_l2cache, tx,
6159                     ZPOOL_CONFIG_L2CACHE, DMU_POOL_L2CACHE);
6160                 spa_errlog_sync(spa, txg);
6161                 dsl_pool_sync(dp, txg);
6162 
6163                 if (pass < zfs_sync_pass_deferred_free) {
6164                         zio_t *zio = zio_root(spa, NULL, NULL, 0);
6165                         bplist_iterate(free_bpl, spa_free_sync_cb,
6166                             zio, tx);
6167                         VERIFY(zio_wait(zio) == 0);
6168                 } else {
6169                         bplist_iterate(free_bpl, bpobj_enqueue_cb,
6170                             defer_bpo, tx);
6171                 }
6172 
6173                 ddt_sync(spa, txg);
6174                 dsl_scan_sync(dp, tx);
6175 
6176                 while (vd = txg_list_remove(&spa->spa_vdev_txg_list, txg))
6177                         vdev_sync(vd, txg);
6178 
6179                 if (pass == 1)
6180                         spa_sync_upgrades(spa, tx);
6181 
6182         } while (dmu_objset_is_dirty(mos, txg));
6183 
6184         /*
6185          * Rewrite the vdev configuration (which includes the uberblock)
6186          * to commit the transaction group.
6187          *
6188          * If there are no dirty vdevs, we sync the uberblock to a few
6189          * random top-level vdevs that are known to be visible in the
6190          * config cache (see spa_vdev_add() for a complete description).
6191          * If there *are* dirty vdevs, sync the uberblock to all vdevs.
6192          */
6193         for (;;) {
6194                 /*
6195                  * We hold SCL_STATE to prevent vdev open/close/etc.
6196                  * while we're attempting to write the vdev labels.
6197                  */
6198                 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
6199 
6200                 if (list_is_empty(&spa->spa_config_dirty_list)) {
6201                         vdev_t *svd[SPA_DVAS_PER_BP];
6202                         int svdcount = 0;
6203                         int children = rvd->vdev_children;
6204                         int c0 = spa_get_random(children);
6205 
6206                         for (int c = 0; c < children; c++) {
6207                                 vd = rvd->vdev_child[(c0 + c) % children];
6208                                 if (vd->vdev_ms_array == 0 || vd->vdev_islog)
6209                                         continue;
6210                                 svd[svdcount++] = vd;
6211                                 if (svdcount == SPA_DVAS_PER_BP)
6212                                         break;
6213                         }
6214                         error = vdev_config_sync(svd, svdcount, txg, B_FALSE);
6215                         if (error != 0)
6216                                 error = vdev_config_sync(svd, svdcount, txg,
6217                                     B_TRUE);
6218                 } else {
6219                         error = vdev_config_sync(rvd->vdev_child,
6220                             rvd->vdev_children, txg, B_FALSE);
6221                         if (error != 0)
6222                                 error = vdev_config_sync(rvd->vdev_child,
6223                                     rvd->vdev_children, txg, B_TRUE);
6224                 }
6225 
6226                 if (error == 0)
6227                         spa->spa_last_synced_guid = rvd->vdev_guid;
6228 
6229                 spa_config_exit(spa, SCL_STATE, FTAG);
6230 
6231                 if (error == 0)
6232                         break;
6233                 zio_suspend(spa, NULL);
6234                 zio_resume_wait(spa);
6235         }
6236         dmu_tx_commit(tx);
6237 
6238         VERIFY(cyclic_reprogram(spa->spa_deadman_cycid, CY_INFINITY));
6239 
6240         /*
6241          * Clear the dirty config list.
6242          */
6243         while ((vd = list_head(&spa->spa_config_dirty_list)) != NULL)
6244                 vdev_config_clean(vd);
6245 
6246         /*
6247          * Now that the new config has synced transactionally,
6248          * let it become visible to the config cache.
6249          */
6250         if (spa->spa_config_syncing != NULL) {
6251                 spa_config_set(spa, spa->spa_config_syncing);
6252                 spa->spa_config_txg = txg;
6253                 spa->spa_config_syncing = NULL;
6254         }
6255 
6256         spa->spa_ubsync = spa->spa_uberblock;
6257 
6258         dsl_pool_sync_done(dp, txg);
6259 
6260         /*
6261          * Update usable space statistics.
6262          */
6263         while (vd = txg_list_remove(&spa->spa_vdev_txg_list, TXG_CLEAN(txg)))
6264                 vdev_sync_done(vd, txg);
6265 
6266         spa_update_dspace(spa);
6267 
6268         /*
6269          * It had better be the case that we didn't dirty anything
6270          * since vdev_config_sync().
6271          */
6272         ASSERT(txg_list_empty(&dp->dp_dirty_datasets, txg));
6273         ASSERT(txg_list_empty(&dp->dp_dirty_dirs, txg));
6274         ASSERT(txg_list_empty(&spa->spa_vdev_txg_list, txg));
6275 
6276         spa->spa_sync_pass = 0;
6277 
6278         spa_config_exit(spa, SCL_CONFIG, FTAG);
6279 
6280         spa_handle_ignored_writes(spa);
6281 
6282         /*
6283          * If any async tasks have been requested, kick them off.
6284          */
6285         spa_async_dispatch(spa);
6286 }
6287 
6288 /*
6289  * Sync all pools.  We don't want to hold the namespace lock across these
6290  * operations, so we take a reference on the spa_t and drop the lock during the
6291  * sync.
6292  */
6293 void
6294 spa_sync_allpools(void)
6295 {
6296         spa_t *spa = NULL;
6297         mutex_enter(&spa_namespace_lock);
6298         while ((spa = spa_next(spa)) != NULL) {
6299                 if (spa_state(spa) != POOL_STATE_ACTIVE ||
6300                     !spa_writeable(spa) || spa_suspended(spa))
6301                         continue;
6302                 spa_open_ref(spa, FTAG);
6303                 mutex_exit(&spa_namespace_lock);
6304                 txg_wait_synced(spa_get_dsl(spa), 0);
6305                 mutex_enter(&spa_namespace_lock);
6306                 spa_close(spa, FTAG);
6307         }
6308         mutex_exit(&spa_namespace_lock);
6309 }
6310 
6311 /*
6312  * ==========================================================================
6313  * Miscellaneous routines
6314  * ==========================================================================
6315  */
6316 
6317 /*
6318  * Remove all pools in the system.
6319  */
6320 void
6321 spa_evict_all(void)
6322 {
6323         spa_t *spa;
6324 
6325         /*
6326          * Remove all cached state.  All pools should be closed now,
6327          * so every spa in the AVL tree should be unreferenced.
6328          */
6329         mutex_enter(&spa_namespace_lock);
6330         while ((spa = spa_next(NULL)) != NULL) {
6331                 /*
6332                  * Stop async tasks.  The async thread may need to detach
6333                  * a device that's been replaced, which requires grabbing
6334                  * spa_namespace_lock, so we must drop it here.
6335                  */
6336                 spa_open_ref(spa, FTAG);
6337                 mutex_exit(&spa_namespace_lock);
6338                 spa_async_suspend(spa);
6339                 mutex_enter(&spa_namespace_lock);
6340                 spa_close(spa, FTAG);
6341 
6342                 if (spa->spa_state != POOL_STATE_UNINITIALIZED) {
6343                         spa_unload(spa);
6344                         spa_deactivate(spa);
6345                 }
6346                 spa_remove(spa);
6347         }
6348         mutex_exit(&spa_namespace_lock);
6349 }
6350 
6351 vdev_t *
6352 spa_lookup_by_guid(spa_t *spa, uint64_t guid, boolean_t aux)
6353 {
6354         vdev_t *vd;
6355         int i;
6356 
6357         if ((vd = vdev_lookup_by_guid(spa->spa_root_vdev, guid)) != NULL)
6358                 return (vd);
6359 
6360         if (aux) {
6361                 for (i = 0; i < spa->spa_l2cache.sav_count; i++) {
6362                         vd = spa->spa_l2cache.sav_vdevs[i];
6363                         if (vd->vdev_guid == guid)
6364                                 return (vd);
6365                 }
6366 
6367                 for (i = 0; i < spa->spa_spares.sav_count; i++) {
6368                         vd = spa->spa_spares.sav_vdevs[i];
6369                         if (vd->vdev_guid == guid)
6370                                 return (vd);
6371                 }
6372         }
6373 
6374         return (NULL);
6375 }
6376 
6377 void
6378 spa_upgrade(spa_t *spa, uint64_t version)
6379 {
6380         ASSERT(spa_writeable(spa));
6381 
6382         spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
6383 
6384         /*
6385          * This should only be called for a non-faulted pool, and since a
6386          * future version would result in an unopenable pool, this shouldn't be
6387          * possible.
6388          */
6389         ASSERT(SPA_VERSION_IS_SUPPORTED(spa->spa_uberblock.ub_version));
6390         ASSERT(version >= spa->spa_uberblock.ub_version);
6391 
6392         spa->spa_uberblock.ub_version = version;
6393         vdev_config_dirty(spa->spa_root_vdev);
6394 
6395         spa_config_exit(spa, SCL_ALL, FTAG);
6396 
6397         txg_wait_synced(spa_get_dsl(spa), 0);
6398 }
6399 
6400 boolean_t
6401 spa_has_spare(spa_t *spa, uint64_t guid)
6402 {
6403         int i;
6404         uint64_t spareguid;
6405         spa_aux_vdev_t *sav = &spa->spa_spares;
6406 
6407         for (i = 0; i < sav->sav_count; i++)
6408                 if (sav->sav_vdevs[i]->vdev_guid == guid)
6409                         return (B_TRUE);
6410 
6411         for (i = 0; i < sav->sav_npending; i++) {
6412                 if (nvlist_lookup_uint64(sav->sav_pending[i], ZPOOL_CONFIG_GUID,
6413                     &spareguid) == 0 && spareguid == guid)
6414                         return (B_TRUE);
6415         }
6416 
6417         return (B_FALSE);
6418 }
6419 
6420 /*
6421  * Check if a pool has an active shared spare device.
6422  * Note: reference count of an active spare is 2, as a spare and as a replace
6423  */
6424 static boolean_t
6425 spa_has_active_shared_spare(spa_t *spa)
6426 {
6427         int i, refcnt;
6428         uint64_t pool;
6429         spa_aux_vdev_t *sav = &spa->spa_spares;
6430 
6431         for (i = 0; i < sav->sav_count; i++) {
6432                 if (spa_spare_exists(sav->sav_vdevs[i]->vdev_guid, &pool,
6433                     &refcnt) && pool != 0ULL && pool == spa_guid(spa) &&
6434                     refcnt > 2)
6435                         return (B_TRUE);
6436         }
6437 
6438         return (B_FALSE);
6439 }
6440 
6441 /*
6442  * Post a sysevent corresponding to the given event.  The 'name' must be one of
6443  * the event definitions in sys/sysevent/eventdefs.h.  The payload will be
6444  * filled in from the spa and (optionally) the vdev.  This doesn't do anything
6445  * in the userland libzpool, as we don't want consumers to misinterpret ztest
6446  * or zdb as real changes.
6447  */
6448 void
6449 spa_event_notify(spa_t *spa, vdev_t *vd, const char *name)
6450 {
6451 #ifdef _KERNEL
6452         sysevent_t              *ev;
6453         sysevent_attr_list_t    *attr = NULL;
6454         sysevent_value_t        value;
6455         sysevent_id_t           eid;
6456 
6457         ev = sysevent_alloc(EC_ZFS, (char *)name, SUNW_KERN_PUB "zfs",
6458             SE_SLEEP);
6459 
6460         value.value_type = SE_DATA_TYPE_STRING;
6461         value.value.sv_string = spa_name(spa);
6462         if (sysevent_add_attr(&attr, ZFS_EV_POOL_NAME, &value, SE_SLEEP) != 0)
6463                 goto done;
6464 
6465         value.value_type = SE_DATA_TYPE_UINT64;
6466         value.value.sv_uint64 = spa_guid(spa);
6467         if (sysevent_add_attr(&attr, ZFS_EV_POOL_GUID, &value, SE_SLEEP) != 0)
6468                 goto done;
6469 
6470         if (vd) {
6471                 value.value_type = SE_DATA_TYPE_UINT64;
6472                 value.value.sv_uint64 = vd->vdev_guid;
6473                 if (sysevent_add_attr(&attr, ZFS_EV_VDEV_GUID, &value,
6474                     SE_SLEEP) != 0)
6475                         goto done;
6476 
6477                 if (vd->vdev_path) {
6478                         value.value_type = SE_DATA_TYPE_STRING;
6479                         value.value.sv_string = vd->vdev_path;
6480                         if (sysevent_add_attr(&attr, ZFS_EV_VDEV_PATH,
6481                             &value, SE_SLEEP) != 0)
6482                                 goto done;
6483                 }
6484         }
6485 
6486         if (sysevent_attach_attributes(ev, attr) != 0)
6487                 goto done;
6488         attr = NULL;
6489 
6490         (void) log_sysevent(ev, SE_SLEEP, &eid);
6491 
6492 done:
6493         if (attr)
6494                 sysevent_free_attr(attr);
6495         sysevent_free(ev);
6496 #endif
6497 }