1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 
  22 /*
  23  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Copyright (c) 2011, 2015 by Delphix. All rights reserved.
  25  * Copyright 2017 Nexenta Systems, Inc.
  26  * Copyright (c) 2014 Integros [integros.com]
  27  * Copyright 2016 Toomas Soome <tsoome@me.com>
  28  * Copyright 2017 Joyent, Inc.
  29  */
  30 
  31 #include <sys/zfs_context.h>
  32 #include <sys/fm/fs/zfs.h>
  33 #include <sys/spa.h>
  34 #include <sys/spa_impl.h>
  35 #include <sys/dmu.h>
  36 #include <sys/dmu_tx.h>
  37 #include <sys/vdev_impl.h>
  38 #include <sys/uberblock_impl.h>
  39 #include <sys/metaslab.h>
  40 #include <sys/metaslab_impl.h>
  41 #include <sys/space_map.h>
  42 #include <sys/space_reftree.h>
  43 #include <sys/zio.h>
  44 #include <sys/zap.h>
  45 #include <sys/fs/zfs.h>
  46 #include <sys/arc.h>
  47 #include <sys/zil.h>
  48 #include <sys/dsl_scan.h>
  49 #include <sys/abd.h>
  50 
  51 /*
  52  * Virtual device management.
  53  */
  54 
  55 static vdev_ops_t *vdev_ops_table[] = {
  56         &vdev_root_ops,
  57         &vdev_raidz_ops,
  58         &vdev_mirror_ops,
  59         &vdev_replacing_ops,
  60         &vdev_spare_ops,
  61         &vdev_disk_ops,
  62         &vdev_file_ops,
  63         &vdev_missing_ops,
  64         &vdev_hole_ops,
  65         NULL
  66 };
  67 
  68 /* maximum scrub/resilver I/O queue per leaf vdev */
  69 int zfs_scrub_limit = 10;
  70 
  71 /*
  72  * When a vdev is added, it will be divided into approximately (but no
  73  * more than) this number of metaslabs.
  74  */
  75 int metaslabs_per_vdev = 200;
  76 
  77 /*
  78  * Given a vdev type, return the appropriate ops vector.
  79  */
  80 static vdev_ops_t *
  81 vdev_getops(const char *type)
  82 {
  83         vdev_ops_t *ops, **opspp;
  84 
  85         for (opspp = vdev_ops_table; (ops = *opspp) != NULL; opspp++)
  86                 if (strcmp(ops->vdev_op_type, type) == 0)
  87                         break;
  88 
  89         return (ops);
  90 }
  91 
  92 /*
  93  * Default asize function: return the MAX of psize with the asize of
  94  * all children.  This is what's used by anything other than RAID-Z.
  95  */
  96 uint64_t
  97 vdev_default_asize(vdev_t *vd, uint64_t psize)
  98 {
  99         uint64_t asize = P2ROUNDUP(psize, 1ULL << vd->vdev_top->vdev_ashift);
 100         uint64_t csize;
 101 
 102         for (int c = 0; c < vd->vdev_children; c++) {
 103                 csize = vdev_psize_to_asize(vd->vdev_child[c], psize);
 104                 asize = MAX(asize, csize);
 105         }
 106 
 107         return (asize);
 108 }
 109 
 110 /*
 111  * Get the minimum allocatable size. We define the allocatable size as
 112  * the vdev's asize rounded to the nearest metaslab. This allows us to
 113  * replace or attach devices which don't have the same physical size but
 114  * can still satisfy the same number of allocations.
 115  */
 116 uint64_t
 117 vdev_get_min_asize(vdev_t *vd)
 118 {
 119         vdev_t *pvd = vd->vdev_parent;
 120 
 121         /*
 122          * If our parent is NULL (inactive spare or cache) or is the root,
 123          * just return our own asize.
 124          */
 125         if (pvd == NULL)
 126                 return (vd->vdev_asize);
 127 
 128         /*
 129          * The top-level vdev just returns the allocatable size rounded
 130          * to the nearest metaslab.
 131          */
 132         if (vd == vd->vdev_top)
 133                 return (P2ALIGN(vd->vdev_asize, 1ULL << vd->vdev_ms_shift));
 134 
 135         /*
 136          * The allocatable space for a raidz vdev is N * sizeof(smallest child),
 137          * so each child must provide at least 1/Nth of its asize.
 138          */
 139         if (pvd->vdev_ops == &vdev_raidz_ops)
 140                 return ((pvd->vdev_min_asize + pvd->vdev_children - 1) /
 141                     pvd->vdev_children);
 142 
 143         return (pvd->vdev_min_asize);
 144 }
 145 
 146 void
 147 vdev_set_min_asize(vdev_t *vd)
 148 {
 149         vd->vdev_min_asize = vdev_get_min_asize(vd);
 150 
 151         for (int c = 0; c < vd->vdev_children; c++)
 152                 vdev_set_min_asize(vd->vdev_child[c]);
 153 }
 154 
 155 vdev_t *
 156 vdev_lookup_top(spa_t *spa, uint64_t vdev)
 157 {
 158         vdev_t *rvd = spa->spa_root_vdev;
 159 
 160         ASSERT(spa_config_held(spa, SCL_ALL, RW_READER) != 0);
 161 
 162         if (vdev < rvd->vdev_children) {
 163                 ASSERT(rvd->vdev_child[vdev] != NULL);
 164                 return (rvd->vdev_child[vdev]);
 165         }
 166 
 167         return (NULL);
 168 }
 169 
 170 vdev_t *
 171 vdev_lookup_by_guid(vdev_t *vd, uint64_t guid)
 172 {
 173         vdev_t *mvd;
 174 
 175         if (vd->vdev_guid == guid)
 176                 return (vd);
 177 
 178         for (int c = 0; c < vd->vdev_children; c++)
 179                 if ((mvd = vdev_lookup_by_guid(vd->vdev_child[c], guid)) !=
 180                     NULL)
 181                         return (mvd);
 182 
 183         return (NULL);
 184 }
 185 
 186 static int
 187 vdev_count_leaves_impl(vdev_t *vd)
 188 {
 189         int n = 0;
 190 
 191         if (vd->vdev_ops->vdev_op_leaf)
 192                 return (1);
 193 
 194         for (int c = 0; c < vd->vdev_children; c++)
 195                 n += vdev_count_leaves_impl(vd->vdev_child[c]);
 196 
 197         return (n);
 198 }
 199 
 200 int
 201 vdev_count_leaves(spa_t *spa)
 202 {
 203         return (vdev_count_leaves_impl(spa->spa_root_vdev));
 204 }
 205 
 206 void
 207 vdev_add_child(vdev_t *pvd, vdev_t *cvd)
 208 {
 209         size_t oldsize, newsize;
 210         uint64_t id = cvd->vdev_id;
 211         vdev_t **newchild;
 212         spa_t *spa = cvd->vdev_spa;
 213 
 214         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
 215         ASSERT(cvd->vdev_parent == NULL);
 216 
 217         cvd->vdev_parent = pvd;
 218 
 219         if (pvd == NULL)
 220                 return;
 221 
 222         ASSERT(id >= pvd->vdev_children || pvd->vdev_child[id] == NULL);
 223 
 224         oldsize = pvd->vdev_children * sizeof (vdev_t *);
 225         pvd->vdev_children = MAX(pvd->vdev_children, id + 1);
 226         newsize = pvd->vdev_children * sizeof (vdev_t *);
 227 
 228         newchild = kmem_zalloc(newsize, KM_SLEEP);
 229         if (pvd->vdev_child != NULL) {
 230                 bcopy(pvd->vdev_child, newchild, oldsize);
 231                 kmem_free(pvd->vdev_child, oldsize);
 232         }
 233 
 234         pvd->vdev_child = newchild;
 235         pvd->vdev_child[id] = cvd;
 236 
 237         cvd->vdev_top = (pvd->vdev_top ? pvd->vdev_top: cvd);
 238         ASSERT(cvd->vdev_top->vdev_parent->vdev_parent == NULL);
 239 
 240         /*
 241          * Walk up all ancestors to update guid sum.
 242          */
 243         for (; pvd != NULL; pvd = pvd->vdev_parent)
 244                 pvd->vdev_guid_sum += cvd->vdev_guid_sum;
 245 }
 246 
 247 void
 248 vdev_remove_child(vdev_t *pvd, vdev_t *cvd)
 249 {
 250         int c;
 251         uint_t id = cvd->vdev_id;
 252 
 253         ASSERT(cvd->vdev_parent == pvd);
 254 
 255         if (pvd == NULL)
 256                 return;
 257 
 258         ASSERT(id < pvd->vdev_children);
 259         ASSERT(pvd->vdev_child[id] == cvd);
 260 
 261         pvd->vdev_child[id] = NULL;
 262         cvd->vdev_parent = NULL;
 263 
 264         for (c = 0; c < pvd->vdev_children; c++)
 265                 if (pvd->vdev_child[c])
 266                         break;
 267 
 268         if (c == pvd->vdev_children) {
 269                 kmem_free(pvd->vdev_child, c * sizeof (vdev_t *));
 270                 pvd->vdev_child = NULL;
 271                 pvd->vdev_children = 0;
 272         }
 273 
 274         /*
 275          * Walk up all ancestors to update guid sum.
 276          */
 277         for (; pvd != NULL; pvd = pvd->vdev_parent)
 278                 pvd->vdev_guid_sum -= cvd->vdev_guid_sum;
 279 }
 280 
 281 /*
 282  * Remove any holes in the child array.
 283  */
 284 void
 285 vdev_compact_children(vdev_t *pvd)
 286 {
 287         vdev_t **newchild, *cvd;
 288         int oldc = pvd->vdev_children;
 289         int newc;
 290 
 291         ASSERT(spa_config_held(pvd->vdev_spa, SCL_ALL, RW_WRITER) == SCL_ALL);
 292 
 293         for (int c = newc = 0; c < oldc; c++)
 294                 if (pvd->vdev_child[c])
 295                         newc++;
 296 
 297         newchild = kmem_alloc(newc * sizeof (vdev_t *), KM_SLEEP);
 298 
 299         for (int c = newc = 0; c < oldc; c++) {
 300                 if ((cvd = pvd->vdev_child[c]) != NULL) {
 301                         newchild[newc] = cvd;
 302                         cvd->vdev_id = newc++;
 303                 }
 304         }
 305 
 306         kmem_free(pvd->vdev_child, oldc * sizeof (vdev_t *));
 307         pvd->vdev_child = newchild;
 308         pvd->vdev_children = newc;
 309 }
 310 
 311 /*
 312  * Allocate and minimally initialize a vdev_t.
 313  */
 314 vdev_t *
 315 vdev_alloc_common(spa_t *spa, uint_t id, uint64_t guid, vdev_ops_t *ops)
 316 {
 317         vdev_t *vd;
 318 
 319         vd = kmem_zalloc(sizeof (vdev_t), KM_SLEEP);
 320 
 321         if (spa->spa_root_vdev == NULL) {
 322                 ASSERT(ops == &vdev_root_ops);
 323                 spa->spa_root_vdev = vd;
 324                 spa->spa_load_guid = spa_generate_guid(NULL);
 325         }
 326 
 327         if (guid == 0 && ops != &vdev_hole_ops) {
 328                 if (spa->spa_root_vdev == vd) {
 329                         /*
 330                          * The root vdev's guid will also be the pool guid,
 331                          * which must be unique among all pools.
 332                          */
 333                         guid = spa_generate_guid(NULL);
 334                 } else {
 335                         /*
 336                          * Any other vdev's guid must be unique within the pool.
 337                          */
 338                         guid = spa_generate_guid(spa);
 339                 }
 340                 ASSERT(!spa_guid_exists(spa_guid(spa), guid));
 341         }
 342 
 343         vd->vdev_spa = spa;
 344         vd->vdev_id = id;
 345         vd->vdev_guid = guid;
 346         vd->vdev_guid_sum = guid;
 347         vd->vdev_ops = ops;
 348         vd->vdev_state = VDEV_STATE_CLOSED;
 349         vd->vdev_ishole = (ops == &vdev_hole_ops);
 350 
 351         mutex_init(&vd->vdev_dtl_lock, NULL, MUTEX_DEFAULT, NULL);
 352         mutex_init(&vd->vdev_stat_lock, NULL, MUTEX_DEFAULT, NULL);
 353         mutex_init(&vd->vdev_probe_lock, NULL, MUTEX_DEFAULT, NULL);
 354         mutex_init(&vd->vdev_queue_lock, NULL, MUTEX_DEFAULT, NULL);
 355         for (int t = 0; t < DTL_TYPES; t++) {
 356                 vd->vdev_dtl[t] = range_tree_create(NULL, NULL,
 357                     &vd->vdev_dtl_lock);
 358         }
 359         txg_list_create(&vd->vdev_ms_list, spa,
 360             offsetof(struct metaslab, ms_txg_node));
 361         txg_list_create(&vd->vdev_dtl_list, spa,
 362             offsetof(struct vdev, vdev_dtl_node));
 363         vd->vdev_stat.vs_timestamp = gethrtime();
 364         vdev_queue_init(vd);
 365         vdev_cache_init(vd);
 366 
 367         return (vd);
 368 }
 369 
 370 /*
 371  * Allocate a new vdev.  The 'alloctype' is used to control whether we are
 372  * creating a new vdev or loading an existing one - the behavior is slightly
 373  * different for each case.
 374  */
 375 int
 376 vdev_alloc(spa_t *spa, vdev_t **vdp, nvlist_t *nv, vdev_t *parent, uint_t id,
 377     int alloctype)
 378 {
 379         vdev_ops_t *ops;
 380         char *type;
 381         uint64_t guid = 0, islog, nparity;
 382         vdev_t *vd;
 383 
 384         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
 385 
 386         if (nvlist_lookup_string(nv, ZPOOL_CONFIG_TYPE, &type) != 0)
 387                 return (SET_ERROR(EINVAL));
 388 
 389         if ((ops = vdev_getops(type)) == NULL)
 390                 return (SET_ERROR(EINVAL));
 391 
 392         /*
 393          * If this is a load, get the vdev guid from the nvlist.
 394          * Otherwise, vdev_alloc_common() will generate one for us.
 395          */
 396         if (alloctype == VDEV_ALLOC_LOAD) {
 397                 uint64_t label_id;
 398 
 399                 if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_ID, &label_id) ||
 400                     label_id != id)
 401                         return (SET_ERROR(EINVAL));
 402 
 403                 if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_GUID, &guid) != 0)
 404                         return (SET_ERROR(EINVAL));
 405         } else if (alloctype == VDEV_ALLOC_SPARE) {
 406                 if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_GUID, &guid) != 0)
 407                         return (SET_ERROR(EINVAL));
 408         } else if (alloctype == VDEV_ALLOC_L2CACHE) {
 409                 if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_GUID, &guid) != 0)
 410                         return (SET_ERROR(EINVAL));
 411         } else if (alloctype == VDEV_ALLOC_ROOTPOOL) {
 412                 if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_GUID, &guid) != 0)
 413                         return (SET_ERROR(EINVAL));
 414         }
 415 
 416         /*
 417          * The first allocated vdev must be of type 'root'.
 418          */
 419         if (ops != &vdev_root_ops && spa->spa_root_vdev == NULL)
 420                 return (SET_ERROR(EINVAL));
 421 
 422         /*
 423          * Determine whether we're a log vdev.
 424          */
 425         islog = 0;
 426         (void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_IS_LOG, &islog);
 427         if (islog && spa_version(spa) < SPA_VERSION_SLOGS)
 428                 return (SET_ERROR(ENOTSUP));
 429 
 430         if (ops == &vdev_hole_ops && spa_version(spa) < SPA_VERSION_HOLES)
 431                 return (SET_ERROR(ENOTSUP));
 432 
 433         /*
 434          * Set the nparity property for RAID-Z vdevs.
 435          */
 436         nparity = -1ULL;
 437         if (ops == &vdev_raidz_ops) {
 438                 if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_NPARITY,
 439                     &nparity) == 0) {
 440                         if (nparity == 0 || nparity > VDEV_RAIDZ_MAXPARITY)
 441                                 return (SET_ERROR(EINVAL));
 442                         /*
 443                          * Previous versions could only support 1 or 2 parity
 444                          * device.
 445                          */
 446                         if (nparity > 1 &&
 447                             spa_version(spa) < SPA_VERSION_RAIDZ2)
 448                                 return (SET_ERROR(ENOTSUP));
 449                         if (nparity > 2 &&
 450                             spa_version(spa) < SPA_VERSION_RAIDZ3)
 451                                 return (SET_ERROR(ENOTSUP));
 452                 } else {
 453                         /*
 454                          * We require the parity to be specified for SPAs that
 455                          * support multiple parity levels.
 456                          */
 457                         if (spa_version(spa) >= SPA_VERSION_RAIDZ2)
 458                                 return (SET_ERROR(EINVAL));
 459                         /*
 460                          * Otherwise, we default to 1 parity device for RAID-Z.
 461                          */
 462                         nparity = 1;
 463                 }
 464         } else {
 465                 nparity = 0;
 466         }
 467         ASSERT(nparity != -1ULL);
 468 
 469         vd = vdev_alloc_common(spa, id, guid, ops);
 470 
 471         vd->vdev_islog = islog;
 472         vd->vdev_nparity = nparity;
 473 
 474         if (nvlist_lookup_string(nv, ZPOOL_CONFIG_PATH, &vd->vdev_path) == 0)
 475                 vd->vdev_path = spa_strdup(vd->vdev_path);
 476         if (nvlist_lookup_string(nv, ZPOOL_CONFIG_DEVID, &vd->vdev_devid) == 0)
 477                 vd->vdev_devid = spa_strdup(vd->vdev_devid);
 478         if (nvlist_lookup_string(nv, ZPOOL_CONFIG_PHYS_PATH,
 479             &vd->vdev_physpath) == 0)
 480                 vd->vdev_physpath = spa_strdup(vd->vdev_physpath);
 481         if (nvlist_lookup_string(nv, ZPOOL_CONFIG_FRU, &vd->vdev_fru) == 0)
 482                 vd->vdev_fru = spa_strdup(vd->vdev_fru);
 483 
 484         /*
 485          * Set the whole_disk property.  If it's not specified, leave the value
 486          * as -1.
 487          */
 488         if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_WHOLE_DISK,
 489             &vd->vdev_wholedisk) != 0)
 490                 vd->vdev_wholedisk = -1ULL;
 491 
 492         /*
 493          * Look for the 'not present' flag.  This will only be set if the device
 494          * was not present at the time of import.
 495          */
 496         (void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_NOT_PRESENT,
 497             &vd->vdev_not_present);
 498 
 499         /*
 500          * Get the alignment requirement.
 501          */
 502         (void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_ASHIFT, &vd->vdev_ashift);
 503 
 504         /*
 505          * Retrieve the vdev creation time.
 506          */
 507         (void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_CREATE_TXG,
 508             &vd->vdev_crtxg);
 509 
 510         /*
 511          * If we're a top-level vdev, try to load the allocation parameters.
 512          */
 513         if (parent && !parent->vdev_parent &&
 514             (alloctype == VDEV_ALLOC_LOAD || alloctype == VDEV_ALLOC_SPLIT)) {
 515                 (void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_METASLAB_ARRAY,
 516                     &vd->vdev_ms_array);
 517                 (void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_METASLAB_SHIFT,
 518                     &vd->vdev_ms_shift);
 519                 (void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_ASIZE,
 520                     &vd->vdev_asize);
 521                 (void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_REMOVING,
 522                     &vd->vdev_removing);
 523                 (void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_VDEV_TOP_ZAP,
 524                     &vd->vdev_top_zap);
 525         } else {
 526                 ASSERT0(vd->vdev_top_zap);
 527         }
 528 
 529         if (parent && !parent->vdev_parent && alloctype != VDEV_ALLOC_ATTACH) {
 530                 ASSERT(alloctype == VDEV_ALLOC_LOAD ||
 531                     alloctype == VDEV_ALLOC_ADD ||
 532                     alloctype == VDEV_ALLOC_SPLIT ||
 533                     alloctype == VDEV_ALLOC_ROOTPOOL);
 534                 vd->vdev_mg = metaslab_group_create(islog ?
 535                     spa_log_class(spa) : spa_normal_class(spa), vd);
 536         }
 537 
 538         if (vd->vdev_ops->vdev_op_leaf &&
 539             (alloctype == VDEV_ALLOC_LOAD || alloctype == VDEV_ALLOC_SPLIT)) {
 540                 (void) nvlist_lookup_uint64(nv,
 541                     ZPOOL_CONFIG_VDEV_LEAF_ZAP, &vd->vdev_leaf_zap);
 542         } else {
 543                 ASSERT0(vd->vdev_leaf_zap);
 544         }
 545 
 546         /*
 547          * If we're a leaf vdev, try to load the DTL object and other state.
 548          */
 549 
 550         if (vd->vdev_ops->vdev_op_leaf &&
 551             (alloctype == VDEV_ALLOC_LOAD || alloctype == VDEV_ALLOC_L2CACHE ||
 552             alloctype == VDEV_ALLOC_ROOTPOOL)) {
 553                 if (alloctype == VDEV_ALLOC_LOAD) {
 554                         (void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_DTL,
 555                             &vd->vdev_dtl_object);
 556                         (void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_UNSPARE,
 557                             &vd->vdev_unspare);
 558                 }
 559 
 560                 if (alloctype == VDEV_ALLOC_ROOTPOOL) {
 561                         uint64_t spare = 0;
 562 
 563                         if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_IS_SPARE,
 564                             &spare) == 0 && spare)
 565                                 spa_spare_add(vd);
 566                 }
 567 
 568                 (void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_OFFLINE,
 569                     &vd->vdev_offline);
 570 
 571                 (void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_RESILVER_TXG,
 572                     &vd->vdev_resilver_txg);
 573 
 574                 /*
 575                  * When importing a pool, we want to ignore the persistent fault
 576                  * state, as the diagnosis made on another system may not be
 577                  * valid in the current context.  Local vdevs will
 578                  * remain in the faulted state.
 579                  */
 580                 if (spa_load_state(spa) == SPA_LOAD_OPEN) {
 581                         (void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_FAULTED,
 582                             &vd->vdev_faulted);
 583                         (void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_DEGRADED,
 584                             &vd->vdev_degraded);
 585                         (void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_REMOVED,
 586                             &vd->vdev_removed);
 587 
 588                         if (vd->vdev_faulted || vd->vdev_degraded) {
 589                                 char *aux;
 590 
 591                                 vd->vdev_label_aux =
 592                                     VDEV_AUX_ERR_EXCEEDED;
 593                                 if (nvlist_lookup_string(nv,
 594                                     ZPOOL_CONFIG_AUX_STATE, &aux) == 0 &&
 595                                     strcmp(aux, "external") == 0)
 596                                         vd->vdev_label_aux = VDEV_AUX_EXTERNAL;
 597                         }
 598                 }
 599         }
 600 
 601         /*
 602          * Add ourselves to the parent's list of children.
 603          */
 604         vdev_add_child(parent, vd);
 605 
 606         *vdp = vd;
 607 
 608         return (0);
 609 }
 610 
 611 void
 612 vdev_free(vdev_t *vd)
 613 {
 614         spa_t *spa = vd->vdev_spa;
 615 
 616         /*
 617          * vdev_free() implies closing the vdev first.  This is simpler than
 618          * trying to ensure complicated semantics for all callers.
 619          */
 620         vdev_close(vd);
 621 
 622         ASSERT(!list_link_active(&vd->vdev_config_dirty_node));
 623         ASSERT(!list_link_active(&vd->vdev_state_dirty_node));
 624 
 625         /*
 626          * Free all children.
 627          */
 628         for (int c = 0; c < vd->vdev_children; c++)
 629                 vdev_free(vd->vdev_child[c]);
 630 
 631         ASSERT(vd->vdev_child == NULL);
 632         ASSERT(vd->vdev_guid_sum == vd->vdev_guid);
 633 
 634         /*
 635          * Discard allocation state.
 636          */
 637         if (vd->vdev_mg != NULL) {
 638                 vdev_metaslab_fini(vd);
 639                 metaslab_group_destroy(vd->vdev_mg);
 640         }
 641 
 642         ASSERT0(vd->vdev_stat.vs_space);
 643         ASSERT0(vd->vdev_stat.vs_dspace);
 644         ASSERT0(vd->vdev_stat.vs_alloc);
 645 
 646         /*
 647          * Remove this vdev from its parent's child list.
 648          */
 649         vdev_remove_child(vd->vdev_parent, vd);
 650 
 651         ASSERT(vd->vdev_parent == NULL);
 652 
 653         /*
 654          * Clean up vdev structure.
 655          */
 656         vdev_queue_fini(vd);
 657         vdev_cache_fini(vd);
 658 
 659         if (vd->vdev_path)
 660                 spa_strfree(vd->vdev_path);
 661         if (vd->vdev_devid)
 662                 spa_strfree(vd->vdev_devid);
 663         if (vd->vdev_physpath)
 664                 spa_strfree(vd->vdev_physpath);
 665         if (vd->vdev_fru)
 666                 spa_strfree(vd->vdev_fru);
 667 
 668         if (vd->vdev_isspare)
 669                 spa_spare_remove(vd);
 670         if (vd->vdev_isl2cache)
 671                 spa_l2cache_remove(vd);
 672 
 673         txg_list_destroy(&vd->vdev_ms_list);
 674         txg_list_destroy(&vd->vdev_dtl_list);
 675 
 676         mutex_enter(&vd->vdev_dtl_lock);
 677         space_map_close(vd->vdev_dtl_sm);
 678         for (int t = 0; t < DTL_TYPES; t++) {
 679                 range_tree_vacate(vd->vdev_dtl[t], NULL, NULL);
 680                 range_tree_destroy(vd->vdev_dtl[t]);
 681         }
 682         mutex_exit(&vd->vdev_dtl_lock);
 683 
 684         mutex_destroy(&vd->vdev_queue_lock);
 685         mutex_destroy(&vd->vdev_dtl_lock);
 686         mutex_destroy(&vd->vdev_stat_lock);
 687         mutex_destroy(&vd->vdev_probe_lock);
 688 
 689         if (vd == spa->spa_root_vdev)
 690                 spa->spa_root_vdev = NULL;
 691 
 692         kmem_free(vd, sizeof (vdev_t));
 693 }
 694 
 695 /*
 696  * Transfer top-level vdev state from svd to tvd.
 697  */
 698 static void
 699 vdev_top_transfer(vdev_t *svd, vdev_t *tvd)
 700 {
 701         spa_t *spa = svd->vdev_spa;
 702         metaslab_t *msp;
 703         vdev_t *vd;
 704         int t;
 705 
 706         ASSERT(tvd == tvd->vdev_top);
 707 
 708         tvd->vdev_ms_array = svd->vdev_ms_array;
 709         tvd->vdev_ms_shift = svd->vdev_ms_shift;
 710         tvd->vdev_ms_count = svd->vdev_ms_count;
 711         tvd->vdev_top_zap = svd->vdev_top_zap;
 712 
 713         svd->vdev_ms_array = 0;
 714         svd->vdev_ms_shift = 0;
 715         svd->vdev_ms_count = 0;
 716         svd->vdev_top_zap = 0;
 717 
 718         if (tvd->vdev_mg)
 719                 ASSERT3P(tvd->vdev_mg, ==, svd->vdev_mg);
 720         tvd->vdev_mg = svd->vdev_mg;
 721         tvd->vdev_ms = svd->vdev_ms;
 722 
 723         svd->vdev_mg = NULL;
 724         svd->vdev_ms = NULL;
 725 
 726         if (tvd->vdev_mg != NULL)
 727                 tvd->vdev_mg->mg_vd = tvd;
 728 
 729         tvd->vdev_stat.vs_alloc = svd->vdev_stat.vs_alloc;
 730         tvd->vdev_stat.vs_space = svd->vdev_stat.vs_space;
 731         tvd->vdev_stat.vs_dspace = svd->vdev_stat.vs_dspace;
 732 
 733         svd->vdev_stat.vs_alloc = 0;
 734         svd->vdev_stat.vs_space = 0;
 735         svd->vdev_stat.vs_dspace = 0;
 736 
 737         for (t = 0; t < TXG_SIZE; t++) {
 738                 while ((msp = txg_list_remove(&svd->vdev_ms_list, t)) != NULL)
 739                         (void) txg_list_add(&tvd->vdev_ms_list, msp, t);
 740                 while ((vd = txg_list_remove(&svd->vdev_dtl_list, t)) != NULL)
 741                         (void) txg_list_add(&tvd->vdev_dtl_list, vd, t);
 742                 if (txg_list_remove_this(&spa->spa_vdev_txg_list, svd, t))
 743                         (void) txg_list_add(&spa->spa_vdev_txg_list, tvd, t);
 744         }
 745 
 746         if (list_link_active(&svd->vdev_config_dirty_node)) {
 747                 vdev_config_clean(svd);
 748                 vdev_config_dirty(tvd);
 749         }
 750 
 751         if (list_link_active(&svd->vdev_state_dirty_node)) {
 752                 vdev_state_clean(svd);
 753                 vdev_state_dirty(tvd);
 754         }
 755 
 756         tvd->vdev_deflate_ratio = svd->vdev_deflate_ratio;
 757         svd->vdev_deflate_ratio = 0;
 758 
 759         tvd->vdev_islog = svd->vdev_islog;
 760         svd->vdev_islog = 0;
 761 }
 762 
 763 static void
 764 vdev_top_update(vdev_t *tvd, vdev_t *vd)
 765 {
 766         if (vd == NULL)
 767                 return;
 768 
 769         vd->vdev_top = tvd;
 770 
 771         for (int c = 0; c < vd->vdev_children; c++)
 772                 vdev_top_update(tvd, vd->vdev_child[c]);
 773 }
 774 
 775 /*
 776  * Add a mirror/replacing vdev above an existing vdev.
 777  */
 778 vdev_t *
 779 vdev_add_parent(vdev_t *cvd, vdev_ops_t *ops)
 780 {
 781         spa_t *spa = cvd->vdev_spa;
 782         vdev_t *pvd = cvd->vdev_parent;
 783         vdev_t *mvd;
 784 
 785         ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
 786 
 787         mvd = vdev_alloc_common(spa, cvd->vdev_id, 0, ops);
 788 
 789         mvd->vdev_asize = cvd->vdev_asize;
 790         mvd->vdev_min_asize = cvd->vdev_min_asize;
 791         mvd->vdev_max_asize = cvd->vdev_max_asize;
 792         mvd->vdev_ashift = cvd->vdev_ashift;
 793         mvd->vdev_state = cvd->vdev_state;
 794         mvd->vdev_crtxg = cvd->vdev_crtxg;
 795 
 796         vdev_remove_child(pvd, cvd);
 797         vdev_add_child(pvd, mvd);
 798         cvd->vdev_id = mvd->vdev_children;
 799         vdev_add_child(mvd, cvd);
 800         vdev_top_update(cvd->vdev_top, cvd->vdev_top);
 801 
 802         if (mvd == mvd->vdev_top)
 803                 vdev_top_transfer(cvd, mvd);
 804 
 805         return (mvd);
 806 }
 807 
 808 /*
 809  * Remove a 1-way mirror/replacing vdev from the tree.
 810  */
 811 void
 812 vdev_remove_parent(vdev_t *cvd)
 813 {
 814         vdev_t *mvd = cvd->vdev_parent;
 815         vdev_t *pvd = mvd->vdev_parent;
 816 
 817         ASSERT(spa_config_held(cvd->vdev_spa, SCL_ALL, RW_WRITER) == SCL_ALL);
 818 
 819         ASSERT(mvd->vdev_children == 1);
 820         ASSERT(mvd->vdev_ops == &vdev_mirror_ops ||
 821             mvd->vdev_ops == &vdev_replacing_ops ||
 822             mvd->vdev_ops == &vdev_spare_ops);
 823         cvd->vdev_ashift = mvd->vdev_ashift;
 824 
 825         vdev_remove_child(mvd, cvd);
 826         vdev_remove_child(pvd, mvd);
 827 
 828         /*
 829          * If cvd will replace mvd as a top-level vdev, preserve mvd's guid.
 830          * Otherwise, we could have detached an offline device, and when we
 831          * go to import the pool we'll think we have two top-level vdevs,
 832          * instead of a different version of the same top-level vdev.
 833          */
 834         if (mvd->vdev_top == mvd) {
 835                 uint64_t guid_delta = mvd->vdev_guid - cvd->vdev_guid;
 836                 cvd->vdev_orig_guid = cvd->vdev_guid;
 837                 cvd->vdev_guid += guid_delta;
 838                 cvd->vdev_guid_sum += guid_delta;
 839         }
 840         cvd->vdev_id = mvd->vdev_id;
 841         vdev_add_child(pvd, cvd);
 842         vdev_top_update(cvd->vdev_top, cvd->vdev_top);
 843 
 844         if (cvd == cvd->vdev_top)
 845                 vdev_top_transfer(mvd, cvd);
 846 
 847         ASSERT(mvd->vdev_children == 0);
 848         vdev_free(mvd);
 849 }
 850 
 851 int
 852 vdev_metaslab_init(vdev_t *vd, uint64_t txg)
 853 {
 854         spa_t *spa = vd->vdev_spa;
 855         objset_t *mos = spa->spa_meta_objset;
 856         uint64_t m;
 857         uint64_t oldc = vd->vdev_ms_count;
 858         uint64_t newc = vd->vdev_asize >> vd->vdev_ms_shift;
 859         metaslab_t **mspp;
 860         int error;
 861 
 862         ASSERT(txg == 0 || spa_config_held(spa, SCL_ALLOC, RW_WRITER));
 863 
 864         /*
 865          * This vdev is not being allocated from yet or is a hole.
 866          */
 867         if (vd->vdev_ms_shift == 0)
 868                 return (0);
 869 
 870         ASSERT(!vd->vdev_ishole);
 871 
 872         /*
 873          * Compute the raidz-deflation ratio.  Note, we hard-code
 874          * in 128k (1 << 17) because it is the "typical" blocksize.
 875          * Even though SPA_MAXBLOCKSIZE changed, this algorithm can not change,
 876          * otherwise it would inconsistently account for existing bp's.
 877          */
 878         vd->vdev_deflate_ratio = (1 << 17) /
 879             (vdev_psize_to_asize(vd, 1 << 17) >> SPA_MINBLOCKSHIFT);
 880 
 881         ASSERT(oldc <= newc);
 882 
 883         mspp = kmem_zalloc(newc * sizeof (*mspp), KM_SLEEP);
 884 
 885         if (oldc != 0) {
 886                 bcopy(vd->vdev_ms, mspp, oldc * sizeof (*mspp));
 887                 kmem_free(vd->vdev_ms, oldc * sizeof (*mspp));
 888         }
 889 
 890         vd->vdev_ms = mspp;
 891         vd->vdev_ms_count = newc;
 892 
 893         for (m = oldc; m < newc; m++) {
 894                 uint64_t object = 0;
 895 
 896                 if (txg == 0) {
 897                         error = dmu_read(mos, vd->vdev_ms_array,
 898                             m * sizeof (uint64_t), sizeof (uint64_t), &object,
 899                             DMU_READ_PREFETCH);
 900                         if (error)
 901                                 return (error);
 902                 }
 903 
 904                 error = metaslab_init(vd->vdev_mg, m, object, txg,
 905                     &(vd->vdev_ms[m]));
 906                 if (error)
 907                         return (error);
 908         }
 909 
 910         if (txg == 0)
 911                 spa_config_enter(spa, SCL_ALLOC, FTAG, RW_WRITER);
 912 
 913         /*
 914          * If the vdev is being removed we don't activate
 915          * the metaslabs since we want to ensure that no new
 916          * allocations are performed on this device.
 917          */
 918         if (oldc == 0 && !vd->vdev_removing)
 919                 metaslab_group_activate(vd->vdev_mg);
 920 
 921         if (txg == 0)
 922                 spa_config_exit(spa, SCL_ALLOC, FTAG);
 923 
 924         return (0);
 925 }
 926 
 927 void
 928 vdev_metaslab_fini(vdev_t *vd)
 929 {
 930         uint64_t m;
 931         uint64_t count = vd->vdev_ms_count;
 932 
 933         if (vd->vdev_ms != NULL) {
 934                 metaslab_group_passivate(vd->vdev_mg);
 935                 for (m = 0; m < count; m++) {
 936                         metaslab_t *msp = vd->vdev_ms[m];
 937 
 938                         if (msp != NULL)
 939                                 metaslab_fini(msp);
 940                 }
 941                 kmem_free(vd->vdev_ms, count * sizeof (metaslab_t *));
 942                 vd->vdev_ms = NULL;
 943         }
 944 }
 945 
 946 typedef struct vdev_probe_stats {
 947         boolean_t       vps_readable;
 948         boolean_t       vps_writeable;
 949         int             vps_flags;
 950 } vdev_probe_stats_t;
 951 
 952 static void
 953 vdev_probe_done(zio_t *zio)
 954 {
 955         spa_t *spa = zio->io_spa;
 956         vdev_t *vd = zio->io_vd;
 957         vdev_probe_stats_t *vps = zio->io_private;
 958 
 959         ASSERT(vd->vdev_probe_zio != NULL);
 960 
 961         if (zio->io_type == ZIO_TYPE_READ) {
 962                 if (zio->io_error == 0)
 963                         vps->vps_readable = 1;
 964                 if (zio->io_error == 0 && spa_writeable(spa)) {
 965                         zio_nowait(zio_write_phys(vd->vdev_probe_zio, vd,
 966                             zio->io_offset, zio->io_size, zio->io_abd,
 967                             ZIO_CHECKSUM_OFF, vdev_probe_done, vps,
 968                             ZIO_PRIORITY_SYNC_WRITE, vps->vps_flags, B_TRUE));
 969                 } else {
 970                         abd_free(zio->io_abd);
 971                 }
 972         } else if (zio->io_type == ZIO_TYPE_WRITE) {
 973                 if (zio->io_error == 0)
 974                         vps->vps_writeable = 1;
 975                 abd_free(zio->io_abd);
 976         } else if (zio->io_type == ZIO_TYPE_NULL) {
 977                 zio_t *pio;
 978 
 979                 vd->vdev_cant_read |= !vps->vps_readable;
 980                 vd->vdev_cant_write |= !vps->vps_writeable;
 981 
 982                 if (vdev_readable(vd) &&
 983                     (vdev_writeable(vd) || !spa_writeable(spa))) {
 984                         zio->io_error = 0;
 985                 } else {
 986                         ASSERT(zio->io_error != 0);
 987                         zfs_ereport_post(FM_EREPORT_ZFS_PROBE_FAILURE,
 988                             spa, vd, NULL, 0, 0);
 989                         zio->io_error = SET_ERROR(ENXIO);
 990                 }
 991 
 992                 mutex_enter(&vd->vdev_probe_lock);
 993                 ASSERT(vd->vdev_probe_zio == zio);
 994                 vd->vdev_probe_zio = NULL;
 995                 mutex_exit(&vd->vdev_probe_lock);
 996 
 997                 zio_link_t *zl = NULL;
 998                 while ((pio = zio_walk_parents(zio, &zl)) != NULL)
 999                         if (!vdev_accessible(vd, pio))
1000                                 pio->io_error = SET_ERROR(ENXIO);
1001 
1002                 kmem_free(vps, sizeof (*vps));
1003         }
1004 }
1005 
1006 /*
1007  * Determine whether this device is accessible.
1008  *
1009  * Read and write to several known locations: the pad regions of each
1010  * vdev label but the first, which we leave alone in case it contains
1011  * a VTOC.
1012  */
1013 zio_t *
1014 vdev_probe(vdev_t *vd, zio_t *zio)
1015 {
1016         spa_t *spa = vd->vdev_spa;
1017         vdev_probe_stats_t *vps = NULL;
1018         zio_t *pio;
1019 
1020         ASSERT(vd->vdev_ops->vdev_op_leaf);
1021 
1022         /*
1023          * Don't probe the probe.
1024          */
1025         if (zio && (zio->io_flags & ZIO_FLAG_PROBE))
1026                 return (NULL);
1027 
1028         /*
1029          * To prevent 'probe storms' when a device fails, we create
1030          * just one probe i/o at a time.  All zios that want to probe
1031          * this vdev will become parents of the probe io.
1032          */
1033         mutex_enter(&vd->vdev_probe_lock);
1034 
1035         if ((pio = vd->vdev_probe_zio) == NULL) {
1036                 vps = kmem_zalloc(sizeof (*vps), KM_SLEEP);
1037 
1038                 vps->vps_flags = ZIO_FLAG_CANFAIL | ZIO_FLAG_PROBE |
1039                     ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_AGGREGATE |
1040                     ZIO_FLAG_TRYHARD;
1041 
1042                 if (spa_config_held(spa, SCL_ZIO, RW_WRITER)) {
1043                         /*
1044                          * vdev_cant_read and vdev_cant_write can only
1045                          * transition from TRUE to FALSE when we have the
1046                          * SCL_ZIO lock as writer; otherwise they can only
1047                          * transition from FALSE to TRUE.  This ensures that
1048                          * any zio looking at these values can assume that
1049                          * failures persist for the life of the I/O.  That's
1050                          * important because when a device has intermittent
1051                          * connectivity problems, we want to ensure that
1052                          * they're ascribed to the device (ENXIO) and not
1053                          * the zio (EIO).
1054                          *
1055                          * Since we hold SCL_ZIO as writer here, clear both
1056                          * values so the probe can reevaluate from first
1057                          * principles.
1058                          */
1059                         vps->vps_flags |= ZIO_FLAG_CONFIG_WRITER;
1060                         vd->vdev_cant_read = B_FALSE;
1061                         vd->vdev_cant_write = B_FALSE;
1062                 }
1063 
1064                 vd->vdev_probe_zio = pio = zio_null(NULL, spa, vd,
1065                     vdev_probe_done, vps,
1066                     vps->vps_flags | ZIO_FLAG_DONT_PROPAGATE);
1067 
1068                 /*
1069                  * We can't change the vdev state in this context, so we
1070                  * kick off an async task to do it on our behalf.
1071                  */
1072                 if (zio != NULL) {
1073                         vd->vdev_probe_wanted = B_TRUE;
1074                         spa_async_request(spa, SPA_ASYNC_PROBE);
1075                 }
1076         }
1077 
1078         if (zio != NULL)
1079                 zio_add_child(zio, pio);
1080 
1081         mutex_exit(&vd->vdev_probe_lock);
1082 
1083         if (vps == NULL) {
1084                 ASSERT(zio != NULL);
1085                 return (NULL);
1086         }
1087 
1088         for (int l = 1; l < VDEV_LABELS; l++) {
1089                 zio_nowait(zio_read_phys(pio, vd,
1090                     vdev_label_offset(vd->vdev_psize, l,
1091                     offsetof(vdev_label_t, vl_pad2)), VDEV_PAD_SIZE,
1092                     abd_alloc_for_io(VDEV_PAD_SIZE, B_TRUE),
1093                     ZIO_CHECKSUM_OFF, vdev_probe_done, vps,
1094                     ZIO_PRIORITY_SYNC_READ, vps->vps_flags, B_TRUE));
1095         }
1096 
1097         if (zio == NULL)
1098                 return (pio);
1099 
1100         zio_nowait(pio);
1101         return (NULL);
1102 }
1103 
1104 static void
1105 vdev_open_child(void *arg)
1106 {
1107         vdev_t *vd = arg;
1108 
1109         vd->vdev_open_thread = curthread;
1110         vd->vdev_open_error = vdev_open(vd);
1111         vd->vdev_open_thread = NULL;
1112 }
1113 
1114 boolean_t
1115 vdev_uses_zvols(vdev_t *vd)
1116 {
1117         if (vd->vdev_path && strncmp(vd->vdev_path, ZVOL_DIR,
1118             strlen(ZVOL_DIR)) == 0)
1119                 return (B_TRUE);
1120         for (int c = 0; c < vd->vdev_children; c++)
1121                 if (vdev_uses_zvols(vd->vdev_child[c]))
1122                         return (B_TRUE);
1123         return (B_FALSE);
1124 }
1125 
1126 void
1127 vdev_open_children(vdev_t *vd)
1128 {
1129         taskq_t *tq;
1130         int children = vd->vdev_children;
1131 
1132         /*
1133          * in order to handle pools on top of zvols, do the opens
1134          * in a single thread so that the same thread holds the
1135          * spa_namespace_lock
1136          */
1137         if (vdev_uses_zvols(vd)) {
1138                 for (int c = 0; c < children; c++)
1139                         vd->vdev_child[c]->vdev_open_error =
1140                             vdev_open(vd->vdev_child[c]);
1141                 return;
1142         }
1143         tq = taskq_create("vdev_open", children, minclsyspri,
1144             children, children, TASKQ_PREPOPULATE);
1145 
1146         for (int c = 0; c < children; c++)
1147                 VERIFY(taskq_dispatch(tq, vdev_open_child, vd->vdev_child[c],
1148                     TQ_SLEEP) != NULL);
1149 
1150         taskq_destroy(tq);
1151 }
1152 
1153 /*
1154  * Prepare a virtual device for access.
1155  */
1156 int
1157 vdev_open(vdev_t *vd)
1158 {
1159         spa_t *spa = vd->vdev_spa;
1160         int error;
1161         uint64_t osize = 0;
1162         uint64_t max_osize = 0;
1163         uint64_t asize, max_asize, psize;
1164         uint64_t ashift = 0;
1165 
1166         ASSERT(vd->vdev_open_thread == curthread ||
1167             spa_config_held(spa, SCL_STATE_ALL, RW_WRITER) == SCL_STATE_ALL);
1168         ASSERT(vd->vdev_state == VDEV_STATE_CLOSED ||
1169             vd->vdev_state == VDEV_STATE_CANT_OPEN ||
1170             vd->vdev_state == VDEV_STATE_OFFLINE);
1171 
1172         vd->vdev_stat.vs_aux = VDEV_AUX_NONE;
1173         vd->vdev_cant_read = B_FALSE;
1174         vd->vdev_cant_write = B_FALSE;
1175         vd->vdev_min_asize = vdev_get_min_asize(vd);
1176 
1177         /*
1178          * If this vdev is not removed, check its fault status.  If it's
1179          * faulted, bail out of the open.
1180          */
1181         if (!vd->vdev_removed && vd->vdev_faulted) {
1182                 ASSERT(vd->vdev_children == 0);
1183                 ASSERT(vd->vdev_label_aux == VDEV_AUX_ERR_EXCEEDED ||
1184                     vd->vdev_label_aux == VDEV_AUX_EXTERNAL);
1185                 vdev_set_state(vd, B_TRUE, VDEV_STATE_FAULTED,
1186                     vd->vdev_label_aux);
1187                 return (SET_ERROR(ENXIO));
1188         } else if (vd->vdev_offline) {
1189                 ASSERT(vd->vdev_children == 0);
1190                 vdev_set_state(vd, B_TRUE, VDEV_STATE_OFFLINE, VDEV_AUX_NONE);
1191                 return (SET_ERROR(ENXIO));
1192         }
1193 
1194         error = vd->vdev_ops->vdev_op_open(vd, &osize, &max_osize, &ashift);
1195 
1196         /*
1197          * Reset the vdev_reopening flag so that we actually close
1198          * the vdev on error.
1199          */
1200         vd->vdev_reopening = B_FALSE;
1201         if (zio_injection_enabled && error == 0)
1202                 error = zio_handle_device_injection(vd, NULL, ENXIO);
1203 
1204         if (error) {
1205                 if (vd->vdev_removed &&
1206                     vd->vdev_stat.vs_aux != VDEV_AUX_OPEN_FAILED)
1207                         vd->vdev_removed = B_FALSE;
1208 
1209                 vdev_set_state(vd, B_TRUE, VDEV_STATE_CANT_OPEN,
1210                     vd->vdev_stat.vs_aux);
1211                 return (error);
1212         }
1213 
1214         vd->vdev_removed = B_FALSE;
1215 
1216         /*
1217          * Recheck the faulted flag now that we have confirmed that
1218          * the vdev is accessible.  If we're faulted, bail.
1219          */
1220         if (vd->vdev_faulted) {
1221                 ASSERT(vd->vdev_children == 0);
1222                 ASSERT(vd->vdev_label_aux == VDEV_AUX_ERR_EXCEEDED ||
1223                     vd->vdev_label_aux == VDEV_AUX_EXTERNAL);
1224                 vdev_set_state(vd, B_TRUE, VDEV_STATE_FAULTED,
1225                     vd->vdev_label_aux);
1226                 return (SET_ERROR(ENXIO));
1227         }
1228 
1229         if (vd->vdev_degraded) {
1230                 ASSERT(vd->vdev_children == 0);
1231                 vdev_set_state(vd, B_TRUE, VDEV_STATE_DEGRADED,
1232                     VDEV_AUX_ERR_EXCEEDED);
1233         } else {
1234                 vdev_set_state(vd, B_TRUE, VDEV_STATE_HEALTHY, 0);
1235         }
1236 
1237         /*
1238          * For hole or missing vdevs we just return success.
1239          */
1240         if (vd->vdev_ishole || vd->vdev_ops == &vdev_missing_ops)
1241                 return (0);
1242 
1243         for (int c = 0; c < vd->vdev_children; c++) {
1244                 if (vd->vdev_child[c]->vdev_state != VDEV_STATE_HEALTHY) {
1245                         vdev_set_state(vd, B_TRUE, VDEV_STATE_DEGRADED,
1246                             VDEV_AUX_NONE);
1247                         break;
1248                 }
1249         }
1250 
1251         osize = P2ALIGN(osize, (uint64_t)sizeof (vdev_label_t));
1252         max_osize = P2ALIGN(max_osize, (uint64_t)sizeof (vdev_label_t));
1253 
1254         if (vd->vdev_children == 0) {
1255                 if (osize < SPA_MINDEVSIZE) {
1256                         vdev_set_state(vd, B_TRUE, VDEV_STATE_CANT_OPEN,
1257                             VDEV_AUX_TOO_SMALL);
1258                         return (SET_ERROR(EOVERFLOW));
1259                 }
1260                 psize = osize;
1261                 asize = osize - (VDEV_LABEL_START_SIZE + VDEV_LABEL_END_SIZE);
1262                 max_asize = max_osize - (VDEV_LABEL_START_SIZE +
1263                     VDEV_LABEL_END_SIZE);
1264         } else {
1265                 if (vd->vdev_parent != NULL && osize < SPA_MINDEVSIZE -
1266                     (VDEV_LABEL_START_SIZE + VDEV_LABEL_END_SIZE)) {
1267                         vdev_set_state(vd, B_TRUE, VDEV_STATE_CANT_OPEN,
1268                             VDEV_AUX_TOO_SMALL);
1269                         return (SET_ERROR(EOVERFLOW));
1270                 }
1271                 psize = 0;
1272                 asize = osize;
1273                 max_asize = max_osize;
1274         }
1275 
1276         vd->vdev_psize = psize;
1277 
1278         /*
1279          * Make sure the allocatable size hasn't shrunk too much.
1280          */
1281         if (asize < vd->vdev_min_asize) {
1282                 vdev_set_state(vd, B_TRUE, VDEV_STATE_CANT_OPEN,
1283                     VDEV_AUX_BAD_LABEL);
1284                 return (SET_ERROR(EINVAL));
1285         }
1286 
1287         if (vd->vdev_asize == 0) {
1288                 /*
1289                  * This is the first-ever open, so use the computed values.
1290                  * For testing purposes, a higher ashift can be requested.
1291                  */
1292                 vd->vdev_asize = asize;
1293                 vd->vdev_max_asize = max_asize;
1294                 vd->vdev_ashift = MAX(ashift, vd->vdev_ashift);
1295         } else {
1296                 /*
1297                  * Detect if the alignment requirement has increased.
1298                  * We don't want to make the pool unavailable, just
1299                  * issue a warning instead.
1300                  */
1301                 if (ashift > vd->vdev_top->vdev_ashift &&
1302                     vd->vdev_ops->vdev_op_leaf) {
1303                         cmn_err(CE_WARN,
1304                             "Disk, '%s', has a block alignment that is "
1305                             "larger than the pool's alignment\n",
1306                             vd->vdev_path);
1307                 }
1308                 vd->vdev_max_asize = max_asize;
1309         }
1310 
1311         /*
1312          * If all children are healthy we update asize if either:
1313          * The asize has increased, due to a device expansion caused by dynamic
1314          * LUN growth or vdev replacement, and automatic expansion is enabled;
1315          * making the additional space available.
1316          *
1317          * The asize has decreased, due to a device shrink usually caused by a
1318          * vdev replace with a smaller device. This ensures that calculations
1319          * based of max_asize and asize e.g. esize are always valid. It's safe
1320          * to do this as we've already validated that asize is greater than
1321          * vdev_min_asize.
1322          */
1323         if (vd->vdev_state == VDEV_STATE_HEALTHY &&
1324             ((asize > vd->vdev_asize &&
1325             (vd->vdev_expanding || spa->spa_autoexpand)) ||
1326             (asize < vd->vdev_asize)))
1327                 vd->vdev_asize = asize;
1328 
1329         vdev_set_min_asize(vd);
1330 
1331         /*
1332          * Ensure we can issue some IO before declaring the
1333          * vdev open for business.
1334          */
1335         if (vd->vdev_ops->vdev_op_leaf &&
1336             (error = zio_wait(vdev_probe(vd, NULL))) != 0) {
1337                 vdev_set_state(vd, B_TRUE, VDEV_STATE_FAULTED,
1338                     VDEV_AUX_ERR_EXCEEDED);
1339                 return (error);
1340         }
1341 
1342         /*
1343          * Track the min and max ashift values for normal data devices.
1344          */
1345         if (vd->vdev_top == vd && vd->vdev_ashift != 0 &&
1346             !vd->vdev_islog && vd->vdev_aux == NULL) {
1347                 if (vd->vdev_ashift > spa->spa_max_ashift)
1348                         spa->spa_max_ashift = vd->vdev_ashift;
1349                 if (vd->vdev_ashift < spa->spa_min_ashift)
1350                         spa->spa_min_ashift = vd->vdev_ashift;
1351         }
1352 
1353         /*
1354          * If a leaf vdev has a DTL, and seems healthy, then kick off a
1355          * resilver.  But don't do this if we are doing a reopen for a scrub,
1356          * since this would just restart the scrub we are already doing.
1357          */
1358         if (vd->vdev_ops->vdev_op_leaf && !spa->spa_scrub_reopen &&
1359             vdev_resilver_needed(vd, NULL, NULL))
1360                 spa_async_request(spa, SPA_ASYNC_RESILVER);
1361 
1362         return (0);
1363 }
1364 
1365 /*
1366  * Called once the vdevs are all opened, this routine validates the label
1367  * contents.  This needs to be done before vdev_load() so that we don't
1368  * inadvertently do repair I/Os to the wrong device.
1369  *
1370  * If 'strict' is false ignore the spa guid check. This is necessary because
1371  * if the machine crashed during a re-guid the new guid might have been written
1372  * to all of the vdev labels, but not the cached config. The strict check
1373  * will be performed when the pool is opened again using the mos config.
1374  *
1375  * This function will only return failure if one of the vdevs indicates that it
1376  * has since been destroyed or exported.  This is only possible if
1377  * /etc/zfs/zpool.cache was readonly at the time.  Otherwise, the vdev state
1378  * will be updated but the function will return 0.
1379  */
1380 int
1381 vdev_validate(vdev_t *vd, boolean_t strict)
1382 {
1383         spa_t *spa = vd->vdev_spa;
1384         nvlist_t *label;
1385         uint64_t guid = 0, top_guid;
1386         uint64_t state;
1387 
1388         for (int c = 0; c < vd->vdev_children; c++)
1389                 if (vdev_validate(vd->vdev_child[c], strict) != 0)
1390                         return (SET_ERROR(EBADF));
1391 
1392         /*
1393          * If the device has already failed, or was marked offline, don't do
1394          * any further validation.  Otherwise, label I/O will fail and we will
1395          * overwrite the previous state.
1396          */
1397         if (vd->vdev_ops->vdev_op_leaf && vdev_readable(vd)) {
1398                 uint64_t aux_guid = 0;
1399                 nvlist_t *nvl;
1400                 uint64_t txg = spa_last_synced_txg(spa) != 0 ?
1401                     spa_last_synced_txg(spa) : -1ULL;
1402 
1403                 if ((label = vdev_label_read_config(vd, txg)) == NULL) {
1404                         vdev_set_state(vd, B_TRUE, VDEV_STATE_CANT_OPEN,
1405                             VDEV_AUX_BAD_LABEL);
1406                         return (0);
1407                 }
1408 
1409                 /*
1410                  * Determine if this vdev has been split off into another
1411                  * pool.  If so, then refuse to open it.
1412                  */
1413                 if (nvlist_lookup_uint64(label, ZPOOL_CONFIG_SPLIT_GUID,
1414                     &aux_guid) == 0 && aux_guid == spa_guid(spa)) {
1415                         vdev_set_state(vd, B_FALSE, VDEV_STATE_CANT_OPEN,
1416                             VDEV_AUX_SPLIT_POOL);
1417                         nvlist_free(label);
1418                         return (0);
1419                 }
1420 
1421                 if (strict && (nvlist_lookup_uint64(label,
1422                     ZPOOL_CONFIG_POOL_GUID, &guid) != 0 ||
1423                     guid != spa_guid(spa))) {
1424                         vdev_set_state(vd, B_FALSE, VDEV_STATE_CANT_OPEN,
1425                             VDEV_AUX_CORRUPT_DATA);
1426                         nvlist_free(label);
1427                         return (0);
1428                 }
1429 
1430                 if (nvlist_lookup_nvlist(label, ZPOOL_CONFIG_VDEV_TREE, &nvl)
1431                     != 0 || nvlist_lookup_uint64(nvl, ZPOOL_CONFIG_ORIG_GUID,
1432                     &aux_guid) != 0)
1433                         aux_guid = 0;
1434 
1435                 /*
1436                  * If this vdev just became a top-level vdev because its
1437                  * sibling was detached, it will have adopted the parent's
1438                  * vdev guid -- but the label may or may not be on disk yet.
1439                  * Fortunately, either version of the label will have the
1440                  * same top guid, so if we're a top-level vdev, we can
1441                  * safely compare to that instead.
1442                  *
1443                  * If we split this vdev off instead, then we also check the
1444                  * original pool's guid.  We don't want to consider the vdev
1445                  * corrupt if it is partway through a split operation.
1446                  */
1447                 if (nvlist_lookup_uint64(label, ZPOOL_CONFIG_GUID,
1448                     &guid) != 0 ||
1449                     nvlist_lookup_uint64(label, ZPOOL_CONFIG_TOP_GUID,
1450                     &top_guid) != 0 ||
1451                     ((vd->vdev_guid != guid && vd->vdev_guid != aux_guid) &&
1452                     (vd->vdev_guid != top_guid || vd != vd->vdev_top))) {
1453                         vdev_set_state(vd, B_FALSE, VDEV_STATE_CANT_OPEN,
1454                             VDEV_AUX_CORRUPT_DATA);
1455                         nvlist_free(label);
1456                         return (0);
1457                 }
1458 
1459                 if (nvlist_lookup_uint64(label, ZPOOL_CONFIG_POOL_STATE,
1460                     &state) != 0) {
1461                         vdev_set_state(vd, B_FALSE, VDEV_STATE_CANT_OPEN,
1462                             VDEV_AUX_CORRUPT_DATA);
1463                         nvlist_free(label);
1464                         return (0);
1465                 }
1466 
1467                 nvlist_free(label);
1468 
1469                 /*
1470                  * If this is a verbatim import, no need to check the
1471                  * state of the pool.
1472                  */
1473                 if (!(spa->spa_import_flags & ZFS_IMPORT_VERBATIM) &&
1474                     spa_load_state(spa) == SPA_LOAD_OPEN &&
1475                     state != POOL_STATE_ACTIVE)
1476                         return (SET_ERROR(EBADF));
1477 
1478                 /*
1479                  * If we were able to open and validate a vdev that was
1480                  * previously marked permanently unavailable, clear that state
1481                  * now.
1482                  */
1483                 if (vd->vdev_not_present)
1484                         vd->vdev_not_present = 0;
1485         }
1486 
1487         return (0);
1488 }
1489 
1490 /*
1491  * Close a virtual device.
1492  */
1493 void
1494 vdev_close(vdev_t *vd)
1495 {
1496         spa_t *spa = vd->vdev_spa;
1497         vdev_t *pvd = vd->vdev_parent;
1498 
1499         ASSERT(spa_config_held(spa, SCL_STATE_ALL, RW_WRITER) == SCL_STATE_ALL);
1500 
1501         /*
1502          * If our parent is reopening, then we are as well, unless we are
1503          * going offline.
1504          */
1505         if (pvd != NULL && pvd->vdev_reopening)
1506                 vd->vdev_reopening = (pvd->vdev_reopening && !vd->vdev_offline);
1507 
1508         vd->vdev_ops->vdev_op_close(vd);
1509 
1510         vdev_cache_purge(vd);
1511 
1512         /*
1513          * We record the previous state before we close it, so that if we are
1514          * doing a reopen(), we don't generate FMA ereports if we notice that
1515          * it's still faulted.
1516          */
1517         vd->vdev_prevstate = vd->vdev_state;
1518 
1519         if (vd->vdev_offline)
1520                 vd->vdev_state = VDEV_STATE_OFFLINE;
1521         else
1522                 vd->vdev_state = VDEV_STATE_CLOSED;
1523         vd->vdev_stat.vs_aux = VDEV_AUX_NONE;
1524 }
1525 
1526 void
1527 vdev_hold(vdev_t *vd)
1528 {
1529         spa_t *spa = vd->vdev_spa;
1530 
1531         ASSERT(spa_is_root(spa));
1532         if (spa->spa_state == POOL_STATE_UNINITIALIZED)
1533                 return;
1534 
1535         for (int c = 0; c < vd->vdev_children; c++)
1536                 vdev_hold(vd->vdev_child[c]);
1537 
1538         if (vd->vdev_ops->vdev_op_leaf)
1539                 vd->vdev_ops->vdev_op_hold(vd);
1540 }
1541 
1542 void
1543 vdev_rele(vdev_t *vd)
1544 {
1545         spa_t *spa = vd->vdev_spa;
1546 
1547         ASSERT(spa_is_root(spa));
1548         for (int c = 0; c < vd->vdev_children; c++)
1549                 vdev_rele(vd->vdev_child[c]);
1550 
1551         if (vd->vdev_ops->vdev_op_leaf)
1552                 vd->vdev_ops->vdev_op_rele(vd);
1553 }
1554 
1555 /*
1556  * Reopen all interior vdevs and any unopened leaves.  We don't actually
1557  * reopen leaf vdevs which had previously been opened as they might deadlock
1558  * on the spa_config_lock.  Instead we only obtain the leaf's physical size.
1559  * If the leaf has never been opened then open it, as usual.
1560  */
1561 void
1562 vdev_reopen(vdev_t *vd)
1563 {
1564         spa_t *spa = vd->vdev_spa;
1565 
1566         ASSERT(spa_config_held(spa, SCL_STATE_ALL, RW_WRITER) == SCL_STATE_ALL);
1567 
1568         /* set the reopening flag unless we're taking the vdev offline */
1569         vd->vdev_reopening = !vd->vdev_offline;
1570         vdev_close(vd);
1571         (void) vdev_open(vd);
1572 
1573         /*
1574          * Call vdev_validate() here to make sure we have the same device.
1575          * Otherwise, a device with an invalid label could be successfully
1576          * opened in response to vdev_reopen().
1577          */
1578         if (vd->vdev_aux) {
1579                 (void) vdev_validate_aux(vd);
1580                 if (vdev_readable(vd) && vdev_writeable(vd) &&
1581                     vd->vdev_aux == &spa->spa_l2cache &&
1582                     !l2arc_vdev_present(vd))
1583                         l2arc_add_vdev(spa, vd);
1584         } else {
1585                 (void) vdev_validate(vd, B_TRUE);
1586         }
1587 
1588         /*
1589          * Reassess parent vdev's health.
1590          */
1591         vdev_propagate_state(vd);
1592 }
1593 
1594 int
1595 vdev_create(vdev_t *vd, uint64_t txg, boolean_t isreplacing)
1596 {
1597         int error;
1598 
1599         /*
1600          * Normally, partial opens (e.g. of a mirror) are allowed.
1601          * For a create, however, we want to fail the request if
1602          * there are any components we can't open.
1603          */
1604         error = vdev_open(vd);
1605 
1606         if (error || vd->vdev_state != VDEV_STATE_HEALTHY) {
1607                 vdev_close(vd);
1608                 return (error ? error : ENXIO);
1609         }
1610 
1611         /*
1612          * Recursively load DTLs and initialize all labels.
1613          */
1614         if ((error = vdev_dtl_load(vd)) != 0 ||
1615             (error = vdev_label_init(vd, txg, isreplacing ?
1616             VDEV_LABEL_REPLACE : VDEV_LABEL_CREATE)) != 0) {
1617                 vdev_close(vd);
1618                 return (error);
1619         }
1620 
1621         return (0);
1622 }
1623 
1624 void
1625 vdev_metaslab_set_size(vdev_t *vd)
1626 {
1627         /*
1628          * Aim for roughly metaslabs_per_vdev (default 200) metaslabs per vdev.
1629          */
1630         vd->vdev_ms_shift = highbit64(vd->vdev_asize / metaslabs_per_vdev);
1631         vd->vdev_ms_shift = MAX(vd->vdev_ms_shift, SPA_MAXBLOCKSHIFT);
1632 }
1633 
1634 void
1635 vdev_dirty(vdev_t *vd, int flags, void *arg, uint64_t txg)
1636 {
1637         ASSERT(vd == vd->vdev_top);
1638         ASSERT(!vd->vdev_ishole);
1639         ASSERT(ISP2(flags));
1640         ASSERT(spa_writeable(vd->vdev_spa));
1641 
1642         if (flags & VDD_METASLAB)
1643                 (void) txg_list_add(&vd->vdev_ms_list, arg, txg);
1644 
1645         if (flags & VDD_DTL)
1646                 (void) txg_list_add(&vd->vdev_dtl_list, arg, txg);
1647 
1648         (void) txg_list_add(&vd->vdev_spa->spa_vdev_txg_list, vd, txg);
1649 }
1650 
1651 void
1652 vdev_dirty_leaves(vdev_t *vd, int flags, uint64_t txg)
1653 {
1654         for (int c = 0; c < vd->vdev_children; c++)
1655                 vdev_dirty_leaves(vd->vdev_child[c], flags, txg);
1656 
1657         if (vd->vdev_ops->vdev_op_leaf)
1658                 vdev_dirty(vd->vdev_top, flags, vd, txg);
1659 }
1660 
1661 /*
1662  * DTLs.
1663  *
1664  * A vdev's DTL (dirty time log) is the set of transaction groups for which
1665  * the vdev has less than perfect replication.  There are four kinds of DTL:
1666  *
1667  * DTL_MISSING: txgs for which the vdev has no valid copies of the data
1668  *
1669  * DTL_PARTIAL: txgs for which data is available, but not fully replicated
1670  *
1671  * DTL_SCRUB: the txgs that could not be repaired by the last scrub; upon
1672  *      scrub completion, DTL_SCRUB replaces DTL_MISSING in the range of
1673  *      txgs that was scrubbed.
1674  *
1675  * DTL_OUTAGE: txgs which cannot currently be read, whether due to
1676  *      persistent errors or just some device being offline.
1677  *      Unlike the other three, the DTL_OUTAGE map is not generally
1678  *      maintained; it's only computed when needed, typically to
1679  *      determine whether a device can be detached.
1680  *
1681  * For leaf vdevs, DTL_MISSING and DTL_PARTIAL are identical: the device
1682  * either has the data or it doesn't.
1683  *
1684  * For interior vdevs such as mirror and RAID-Z the picture is more complex.
1685  * A vdev's DTL_PARTIAL is the union of its children's DTL_PARTIALs, because
1686  * if any child is less than fully replicated, then so is its parent.
1687  * A vdev's DTL_MISSING is a modified union of its children's DTL_MISSINGs,
1688  * comprising only those txgs which appear in 'maxfaults' or more children;
1689  * those are the txgs we don't have enough replication to read.  For example,
1690  * double-parity RAID-Z can tolerate up to two missing devices (maxfaults == 2);
1691  * thus, its DTL_MISSING consists of the set of txgs that appear in more than
1692  * two child DTL_MISSING maps.
1693  *
1694  * It should be clear from the above that to compute the DTLs and outage maps
1695  * for all vdevs, it suffices to know just the leaf vdevs' DTL_MISSING maps.
1696  * Therefore, that is all we keep on disk.  When loading the pool, or after
1697  * a configuration change, we generate all other DTLs from first principles.
1698  */
1699 void
1700 vdev_dtl_dirty(vdev_t *vd, vdev_dtl_type_t t, uint64_t txg, uint64_t size)
1701 {
1702         range_tree_t *rt = vd->vdev_dtl[t];
1703 
1704         ASSERT(t < DTL_TYPES);
1705         ASSERT(vd != vd->vdev_spa->spa_root_vdev);
1706         ASSERT(spa_writeable(vd->vdev_spa));
1707 
1708         mutex_enter(rt->rt_lock);
1709         if (!range_tree_contains(rt, txg, size))
1710                 range_tree_add(rt, txg, size);
1711         mutex_exit(rt->rt_lock);
1712 }
1713 
1714 boolean_t
1715 vdev_dtl_contains(vdev_t *vd, vdev_dtl_type_t t, uint64_t txg, uint64_t size)
1716 {
1717         range_tree_t *rt = vd->vdev_dtl[t];
1718         boolean_t dirty = B_FALSE;
1719 
1720         ASSERT(t < DTL_TYPES);
1721         ASSERT(vd != vd->vdev_spa->spa_root_vdev);
1722 
1723         mutex_enter(rt->rt_lock);
1724         if (range_tree_space(rt) != 0)
1725                 dirty = range_tree_contains(rt, txg, size);
1726         mutex_exit(rt->rt_lock);
1727 
1728         return (dirty);
1729 }
1730 
1731 boolean_t
1732 vdev_dtl_empty(vdev_t *vd, vdev_dtl_type_t t)
1733 {
1734         range_tree_t *rt = vd->vdev_dtl[t];
1735         boolean_t empty;
1736 
1737         mutex_enter(rt->rt_lock);
1738         empty = (range_tree_space(rt) == 0);
1739         mutex_exit(rt->rt_lock);
1740 
1741         return (empty);
1742 }
1743 
1744 /*
1745  * Returns the lowest txg in the DTL range.
1746  */
1747 static uint64_t
1748 vdev_dtl_min(vdev_t *vd)
1749 {
1750         range_seg_t *rs;
1751 
1752         ASSERT(MUTEX_HELD(&vd->vdev_dtl_lock));
1753         ASSERT3U(range_tree_space(vd->vdev_dtl[DTL_MISSING]), !=, 0);
1754         ASSERT0(vd->vdev_children);
1755 
1756         rs = avl_first(&vd->vdev_dtl[DTL_MISSING]->rt_root);
1757         return (rs->rs_start - 1);
1758 }
1759 
1760 /*
1761  * Returns the highest txg in the DTL.
1762  */
1763 static uint64_t
1764 vdev_dtl_max(vdev_t *vd)
1765 {
1766         range_seg_t *rs;
1767 
1768         ASSERT(MUTEX_HELD(&vd->vdev_dtl_lock));
1769         ASSERT3U(range_tree_space(vd->vdev_dtl[DTL_MISSING]), !=, 0);
1770         ASSERT0(vd->vdev_children);
1771 
1772         rs = avl_last(&vd->vdev_dtl[DTL_MISSING]->rt_root);
1773         return (rs->rs_end);
1774 }
1775 
1776 /*
1777  * Determine if a resilvering vdev should remove any DTL entries from
1778  * its range. If the vdev was resilvering for the entire duration of the
1779  * scan then it should excise that range from its DTLs. Otherwise, this
1780  * vdev is considered partially resilvered and should leave its DTL
1781  * entries intact. The comment in vdev_dtl_reassess() describes how we
1782  * excise the DTLs.
1783  */
1784 static boolean_t
1785 vdev_dtl_should_excise(vdev_t *vd)
1786 {
1787         spa_t *spa = vd->vdev_spa;
1788         dsl_scan_t *scn = spa->spa_dsl_pool->dp_scan;
1789 
1790         ASSERT0(scn->scn_phys.scn_errors);
1791         ASSERT0(vd->vdev_children);
1792 
1793         if (vd->vdev_state < VDEV_STATE_DEGRADED)
1794                 return (B_FALSE);
1795 
1796         if (vd->vdev_resilver_txg == 0 ||
1797             range_tree_space(vd->vdev_dtl[DTL_MISSING]) == 0)
1798                 return (B_TRUE);
1799 
1800         /*
1801          * When a resilver is initiated the scan will assign the scn_max_txg
1802          * value to the highest txg value that exists in all DTLs. If this
1803          * device's max DTL is not part of this scan (i.e. it is not in
1804          * the range (scn_min_txg, scn_max_txg] then it is not eligible
1805          * for excision.
1806          */
1807         if (vdev_dtl_max(vd) <= scn->scn_phys.scn_max_txg) {
1808                 ASSERT3U(scn->scn_phys.scn_min_txg, <=, vdev_dtl_min(vd));
1809                 ASSERT3U(scn->scn_phys.scn_min_txg, <, vd->vdev_resilver_txg);
1810                 ASSERT3U(vd->vdev_resilver_txg, <=, scn->scn_phys.scn_max_txg);
1811                 return (B_TRUE);
1812         }
1813         return (B_FALSE);
1814 }
1815 
1816 /*
1817  * Reassess DTLs after a config change or scrub completion.
1818  */
1819 void
1820 vdev_dtl_reassess(vdev_t *vd, uint64_t txg, uint64_t scrub_txg, int scrub_done)
1821 {
1822         spa_t *spa = vd->vdev_spa;
1823         avl_tree_t reftree;
1824         int minref;
1825 
1826         ASSERT(spa_config_held(spa, SCL_ALL, RW_READER) != 0);
1827 
1828         for (int c = 0; c < vd->vdev_children; c++)
1829                 vdev_dtl_reassess(vd->vdev_child[c], txg,
1830                     scrub_txg, scrub_done);
1831 
1832         if (vd == spa->spa_root_vdev || vd->vdev_ishole || vd->vdev_aux)
1833                 return;
1834 
1835         if (vd->vdev_ops->vdev_op_leaf) {
1836                 dsl_scan_t *scn = spa->spa_dsl_pool->dp_scan;
1837 
1838                 mutex_enter(&vd->vdev_dtl_lock);
1839 
1840                 /*
1841                  * If we've completed a scan cleanly then determine
1842                  * if this vdev should remove any DTLs. We only want to
1843                  * excise regions on vdevs that were available during
1844                  * the entire duration of this scan.
1845                  */
1846                 if (scrub_txg != 0 &&
1847                     (spa->spa_scrub_started ||
1848                     (scn != NULL && scn->scn_phys.scn_errors == 0)) &&
1849                     vdev_dtl_should_excise(vd)) {
1850                         /*
1851                          * We completed a scrub up to scrub_txg.  If we
1852                          * did it without rebooting, then the scrub dtl
1853                          * will be valid, so excise the old region and
1854                          * fold in the scrub dtl.  Otherwise, leave the
1855                          * dtl as-is if there was an error.
1856                          *
1857                          * There's little trick here: to excise the beginning
1858                          * of the DTL_MISSING map, we put it into a reference
1859                          * tree and then add a segment with refcnt -1 that
1860                          * covers the range [0, scrub_txg).  This means
1861                          * that each txg in that range has refcnt -1 or 0.
1862                          * We then add DTL_SCRUB with a refcnt of 2, so that
1863                          * entries in the range [0, scrub_txg) will have a
1864                          * positive refcnt -- either 1 or 2.  We then convert
1865                          * the reference tree into the new DTL_MISSING map.
1866                          */
1867                         space_reftree_create(&reftree);
1868                         space_reftree_add_map(&reftree,
1869                             vd->vdev_dtl[DTL_MISSING], 1);
1870                         space_reftree_add_seg(&reftree, 0, scrub_txg, -1);
1871                         space_reftree_add_map(&reftree,
1872                             vd->vdev_dtl[DTL_SCRUB], 2);
1873                         space_reftree_generate_map(&reftree,
1874                             vd->vdev_dtl[DTL_MISSING], 1);
1875                         space_reftree_destroy(&reftree);
1876                 }
1877                 range_tree_vacate(vd->vdev_dtl[DTL_PARTIAL], NULL, NULL);
1878                 range_tree_walk(vd->vdev_dtl[DTL_MISSING],
1879                     range_tree_add, vd->vdev_dtl[DTL_PARTIAL]);
1880                 if (scrub_done)
1881                         range_tree_vacate(vd->vdev_dtl[DTL_SCRUB], NULL, NULL);
1882                 range_tree_vacate(vd->vdev_dtl[DTL_OUTAGE], NULL, NULL);
1883                 if (!vdev_readable(vd))
1884                         range_tree_add(vd->vdev_dtl[DTL_OUTAGE], 0, -1ULL);
1885                 else
1886                         range_tree_walk(vd->vdev_dtl[DTL_MISSING],
1887                             range_tree_add, vd->vdev_dtl[DTL_OUTAGE]);
1888 
1889                 /*
1890                  * If the vdev was resilvering and no longer has any
1891                  * DTLs then reset its resilvering flag.
1892                  */
1893                 if (vd->vdev_resilver_txg != 0 &&
1894                     range_tree_space(vd->vdev_dtl[DTL_MISSING]) == 0 &&
1895                     range_tree_space(vd->vdev_dtl[DTL_OUTAGE]) == 0)
1896                         vd->vdev_resilver_txg = 0;
1897 
1898                 mutex_exit(&vd->vdev_dtl_lock);
1899 
1900                 if (txg != 0)
1901                         vdev_dirty(vd->vdev_top, VDD_DTL, vd, txg);
1902                 return;
1903         }
1904 
1905         mutex_enter(&vd->vdev_dtl_lock);
1906         for (int t = 0; t < DTL_TYPES; t++) {
1907                 /* account for child's outage in parent's missing map */
1908                 int s = (t == DTL_MISSING) ? DTL_OUTAGE: t;
1909                 if (t == DTL_SCRUB)
1910                         continue;                       /* leaf vdevs only */
1911                 if (t == DTL_PARTIAL)
1912                         minref = 1;                     /* i.e. non-zero */
1913                 else if (vd->vdev_nparity != 0)
1914                         minref = vd->vdev_nparity + 1;       /* RAID-Z */
1915                 else
1916                         minref = vd->vdev_children;  /* any kind of mirror */
1917                 space_reftree_create(&reftree);
1918                 for (int c = 0; c < vd->vdev_children; c++) {
1919                         vdev_t *cvd = vd->vdev_child[c];
1920                         mutex_enter(&cvd->vdev_dtl_lock);
1921                         space_reftree_add_map(&reftree, cvd->vdev_dtl[s], 1);
1922                         mutex_exit(&cvd->vdev_dtl_lock);
1923                 }
1924                 space_reftree_generate_map(&reftree, vd->vdev_dtl[t], minref);
1925                 space_reftree_destroy(&reftree);
1926         }
1927         mutex_exit(&vd->vdev_dtl_lock);
1928 }
1929 
1930 int
1931 vdev_dtl_load(vdev_t *vd)
1932 {
1933         spa_t *spa = vd->vdev_spa;
1934         objset_t *mos = spa->spa_meta_objset;
1935         int error = 0;
1936 
1937         if (vd->vdev_ops->vdev_op_leaf && vd->vdev_dtl_object != 0) {
1938                 ASSERT(!vd->vdev_ishole);
1939 
1940                 error = space_map_open(&vd->vdev_dtl_sm, mos,
1941                     vd->vdev_dtl_object, 0, -1ULL, 0, &vd->vdev_dtl_lock);
1942                 if (error)
1943                         return (error);
1944                 ASSERT(vd->vdev_dtl_sm != NULL);
1945 
1946                 mutex_enter(&vd->vdev_dtl_lock);
1947 
1948                 /*
1949                  * Now that we've opened the space_map we need to update
1950                  * the in-core DTL.
1951                  */
1952                 space_map_update(vd->vdev_dtl_sm);
1953 
1954                 error = space_map_load(vd->vdev_dtl_sm,
1955                     vd->vdev_dtl[DTL_MISSING], SM_ALLOC);
1956                 mutex_exit(&vd->vdev_dtl_lock);
1957 
1958                 return (error);
1959         }
1960 
1961         for (int c = 0; c < vd->vdev_children; c++) {
1962                 error = vdev_dtl_load(vd->vdev_child[c]);
1963                 if (error != 0)
1964                         break;
1965         }
1966 
1967         return (error);
1968 }
1969 
1970 void
1971 vdev_destroy_unlink_zap(vdev_t *vd, uint64_t zapobj, dmu_tx_t *tx)
1972 {
1973         spa_t *spa = vd->vdev_spa;
1974 
1975         VERIFY0(zap_destroy(spa->spa_meta_objset, zapobj, tx));
1976         VERIFY0(zap_remove_int(spa->spa_meta_objset, spa->spa_all_vdev_zaps,
1977             zapobj, tx));
1978 }
1979 
1980 uint64_t
1981 vdev_create_link_zap(vdev_t *vd, dmu_tx_t *tx)
1982 {
1983         spa_t *spa = vd->vdev_spa;
1984         uint64_t zap = zap_create(spa->spa_meta_objset, DMU_OTN_ZAP_METADATA,
1985             DMU_OT_NONE, 0, tx);
1986 
1987         ASSERT(zap != 0);
1988         VERIFY0(zap_add_int(spa->spa_meta_objset, spa->spa_all_vdev_zaps,
1989             zap, tx));
1990 
1991         return (zap);
1992 }
1993 
1994 void
1995 vdev_construct_zaps(vdev_t *vd, dmu_tx_t *tx)
1996 {
1997         if (vd->vdev_ops != &vdev_hole_ops &&
1998             vd->vdev_ops != &vdev_missing_ops &&
1999             vd->vdev_ops != &vdev_root_ops &&
2000             !vd->vdev_top->vdev_removing) {
2001                 if (vd->vdev_ops->vdev_op_leaf && vd->vdev_leaf_zap == 0) {
2002                         vd->vdev_leaf_zap = vdev_create_link_zap(vd, tx);
2003                 }
2004                 if (vd == vd->vdev_top && vd->vdev_top_zap == 0) {
2005                         vd->vdev_top_zap = vdev_create_link_zap(vd, tx);
2006                 }
2007         }
2008         for (uint64_t i = 0; i < vd->vdev_children; i++) {
2009                 vdev_construct_zaps(vd->vdev_child[i], tx);
2010         }
2011 }
2012 
2013 void
2014 vdev_dtl_sync(vdev_t *vd, uint64_t txg)
2015 {
2016         spa_t *spa = vd->vdev_spa;
2017         range_tree_t *rt = vd->vdev_dtl[DTL_MISSING];
2018         objset_t *mos = spa->spa_meta_objset;
2019         range_tree_t *rtsync;
2020         kmutex_t rtlock;
2021         dmu_tx_t *tx;
2022         uint64_t object = space_map_object(vd->vdev_dtl_sm);
2023 
2024         ASSERT(!vd->vdev_ishole);
2025         ASSERT(vd->vdev_ops->vdev_op_leaf);
2026 
2027         tx = dmu_tx_create_assigned(spa->spa_dsl_pool, txg);
2028 
2029         if (vd->vdev_detached || vd->vdev_top->vdev_removing) {
2030                 mutex_enter(&vd->vdev_dtl_lock);
2031                 space_map_free(vd->vdev_dtl_sm, tx);
2032                 space_map_close(vd->vdev_dtl_sm);
2033                 vd->vdev_dtl_sm = NULL;
2034                 mutex_exit(&vd->vdev_dtl_lock);
2035 
2036                 /*
2037                  * We only destroy the leaf ZAP for detached leaves or for
2038                  * removed log devices. Removed data devices handle leaf ZAP
2039                  * cleanup later, once cancellation is no longer possible.
2040                  */
2041                 if (vd->vdev_leaf_zap != 0 && (vd->vdev_detached ||
2042                     vd->vdev_top->vdev_islog)) {
2043                         vdev_destroy_unlink_zap(vd, vd->vdev_leaf_zap, tx);
2044                         vd->vdev_leaf_zap = 0;
2045                 }
2046 
2047                 dmu_tx_commit(tx);
2048                 return;
2049         }
2050 
2051         if (vd->vdev_dtl_sm == NULL) {
2052                 uint64_t new_object;
2053 
2054                 new_object = space_map_alloc(mos, tx);
2055                 VERIFY3U(new_object, !=, 0);
2056 
2057                 VERIFY0(space_map_open(&vd->vdev_dtl_sm, mos, new_object,
2058                     0, -1ULL, 0, &vd->vdev_dtl_lock));
2059                 ASSERT(vd->vdev_dtl_sm != NULL);
2060         }
2061 
2062         mutex_init(&rtlock, NULL, MUTEX_DEFAULT, NULL);
2063 
2064         rtsync = range_tree_create(NULL, NULL, &rtlock);
2065 
2066         mutex_enter(&rtlock);
2067 
2068         mutex_enter(&vd->vdev_dtl_lock);
2069         range_tree_walk(rt, range_tree_add, rtsync);
2070         mutex_exit(&vd->vdev_dtl_lock);
2071 
2072         space_map_truncate(vd->vdev_dtl_sm, tx);
2073         space_map_write(vd->vdev_dtl_sm, rtsync, SM_ALLOC, tx);
2074         range_tree_vacate(rtsync, NULL, NULL);
2075 
2076         range_tree_destroy(rtsync);
2077 
2078         mutex_exit(&rtlock);
2079         mutex_destroy(&rtlock);
2080 
2081         /*
2082          * If the object for the space map has changed then dirty
2083          * the top level so that we update the config.
2084          */
2085         if (object != space_map_object(vd->vdev_dtl_sm)) {
2086                 zfs_dbgmsg("txg %llu, spa %s, DTL old object %llu, "
2087                     "new object %llu", txg, spa_name(spa), object,
2088                     space_map_object(vd->vdev_dtl_sm));
2089                 vdev_config_dirty(vd->vdev_top);
2090         }
2091 
2092         dmu_tx_commit(tx);
2093 
2094         mutex_enter(&vd->vdev_dtl_lock);
2095         space_map_update(vd->vdev_dtl_sm);
2096         mutex_exit(&vd->vdev_dtl_lock);
2097 }
2098 
2099 /*
2100  * Determine whether the specified vdev can be offlined/detached/removed
2101  * without losing data.
2102  */
2103 boolean_t
2104 vdev_dtl_required(vdev_t *vd)
2105 {
2106         spa_t *spa = vd->vdev_spa;
2107         vdev_t *tvd = vd->vdev_top;
2108         uint8_t cant_read = vd->vdev_cant_read;
2109         boolean_t required;
2110 
2111         ASSERT(spa_config_held(spa, SCL_STATE_ALL, RW_WRITER) == SCL_STATE_ALL);
2112 
2113         if (vd == spa->spa_root_vdev || vd == tvd)
2114                 return (B_TRUE);
2115 
2116         /*
2117          * Temporarily mark the device as unreadable, and then determine
2118          * whether this results in any DTL outages in the top-level vdev.
2119          * If not, we can safely offline/detach/remove the device.
2120          */
2121         vd->vdev_cant_read = B_TRUE;
2122         vdev_dtl_reassess(tvd, 0, 0, B_FALSE);
2123         required = !vdev_dtl_empty(tvd, DTL_OUTAGE);
2124         vd->vdev_cant_read = cant_read;
2125         vdev_dtl_reassess(tvd, 0, 0, B_FALSE);
2126 
2127         if (!required && zio_injection_enabled)
2128                 required = !!zio_handle_device_injection(vd, NULL, ECHILD);
2129 
2130         return (required);
2131 }
2132 
2133 /*
2134  * Determine if resilver is needed, and if so the txg range.
2135  */
2136 boolean_t
2137 vdev_resilver_needed(vdev_t *vd, uint64_t *minp, uint64_t *maxp)
2138 {
2139         boolean_t needed = B_FALSE;
2140         uint64_t thismin = UINT64_MAX;
2141         uint64_t thismax = 0;
2142 
2143         if (vd->vdev_children == 0) {
2144                 mutex_enter(&vd->vdev_dtl_lock);
2145                 if (range_tree_space(vd->vdev_dtl[DTL_MISSING]) != 0 &&
2146                     vdev_writeable(vd)) {
2147 
2148                         thismin = vdev_dtl_min(vd);
2149                         thismax = vdev_dtl_max(vd);
2150                         needed = B_TRUE;
2151                 }
2152                 mutex_exit(&vd->vdev_dtl_lock);
2153         } else {
2154                 for (int c = 0; c < vd->vdev_children; c++) {
2155                         vdev_t *cvd = vd->vdev_child[c];
2156                         uint64_t cmin, cmax;
2157 
2158                         if (vdev_resilver_needed(cvd, &cmin, &cmax)) {
2159                                 thismin = MIN(thismin, cmin);
2160                                 thismax = MAX(thismax, cmax);
2161                                 needed = B_TRUE;
2162                         }
2163                 }
2164         }
2165 
2166         if (needed && minp) {
2167                 *minp = thismin;
2168                 *maxp = thismax;
2169         }
2170         return (needed);
2171 }
2172 
2173 void
2174 vdev_load(vdev_t *vd)
2175 {
2176         /*
2177          * Recursively load all children.
2178          */
2179         for (int c = 0; c < vd->vdev_children; c++)
2180                 vdev_load(vd->vdev_child[c]);
2181 
2182         /*
2183          * If this is a top-level vdev, initialize its metaslabs.
2184          */
2185         if (vd == vd->vdev_top && !vd->vdev_ishole &&
2186             (vd->vdev_ashift == 0 || vd->vdev_asize == 0 ||
2187             vdev_metaslab_init(vd, 0) != 0))
2188                 vdev_set_state(vd, B_FALSE, VDEV_STATE_CANT_OPEN,
2189                     VDEV_AUX_CORRUPT_DATA);
2190 
2191         /*
2192          * If this is a leaf vdev, load its DTL.
2193          */
2194         if (vd->vdev_ops->vdev_op_leaf && vdev_dtl_load(vd) != 0)
2195                 vdev_set_state(vd, B_FALSE, VDEV_STATE_CANT_OPEN,
2196                     VDEV_AUX_CORRUPT_DATA);
2197 }
2198 
2199 /*
2200  * The special vdev case is used for hot spares and l2cache devices.  Its
2201  * sole purpose it to set the vdev state for the associated vdev.  To do this,
2202  * we make sure that we can open the underlying device, then try to read the
2203  * label, and make sure that the label is sane and that it hasn't been
2204  * repurposed to another pool.
2205  */
2206 int
2207 vdev_validate_aux(vdev_t *vd)
2208 {
2209         nvlist_t *label;
2210         uint64_t guid, version;
2211         uint64_t state;
2212 
2213         if (!vdev_readable(vd))
2214                 return (0);
2215 
2216         if ((label = vdev_label_read_config(vd, -1ULL)) == NULL) {
2217                 vdev_set_state(vd, B_TRUE, VDEV_STATE_CANT_OPEN,
2218                     VDEV_AUX_CORRUPT_DATA);
2219                 return (-1);
2220         }
2221 
2222         if (nvlist_lookup_uint64(label, ZPOOL_CONFIG_VERSION, &version) != 0 ||
2223             !SPA_VERSION_IS_SUPPORTED(version) ||
2224             nvlist_lookup_uint64(label, ZPOOL_CONFIG_GUID, &guid) != 0 ||
2225             guid != vd->vdev_guid ||
2226             nvlist_lookup_uint64(label, ZPOOL_CONFIG_POOL_STATE, &state) != 0) {
2227                 vdev_set_state(vd, B_TRUE, VDEV_STATE_CANT_OPEN,
2228                     VDEV_AUX_CORRUPT_DATA);
2229                 nvlist_free(label);
2230                 return (-1);
2231         }
2232 
2233         /*
2234          * We don't actually check the pool state here.  If it's in fact in
2235          * use by another pool, we update this fact on the fly when requested.
2236          */
2237         nvlist_free(label);
2238         return (0);
2239 }
2240 
2241 void
2242 vdev_remove(vdev_t *vd, uint64_t txg)
2243 {
2244         spa_t *spa = vd->vdev_spa;
2245         objset_t *mos = spa->spa_meta_objset;
2246         dmu_tx_t *tx;
2247 
2248         tx = dmu_tx_create_assigned(spa_get_dsl(spa), txg);
2249         ASSERT(vd == vd->vdev_top);
2250         ASSERT3U(txg, ==, spa_syncing_txg(spa));
2251 
2252         if (vd->vdev_ms != NULL) {
2253                 metaslab_group_t *mg = vd->vdev_mg;
2254 
2255                 metaslab_group_histogram_verify(mg);
2256                 metaslab_class_histogram_verify(mg->mg_class);
2257 
2258                 for (int m = 0; m < vd->vdev_ms_count; m++) {
2259                         metaslab_t *msp = vd->vdev_ms[m];
2260 
2261                         if (msp == NULL || msp->ms_sm == NULL)
2262                                 continue;
2263 
2264                         mutex_enter(&msp->ms_lock);
2265                         /*
2266                          * If the metaslab was not loaded when the vdev
2267                          * was removed then the histogram accounting may
2268                          * not be accurate. Update the histogram information
2269                          * here so that we ensure that the metaslab group
2270                          * and metaslab class are up-to-date.
2271                          */
2272                         metaslab_group_histogram_remove(mg, msp);
2273 
2274                         VERIFY0(space_map_allocated(msp->ms_sm));
2275                         space_map_free(msp->ms_sm, tx);
2276                         space_map_close(msp->ms_sm);
2277                         msp->ms_sm = NULL;
2278                         mutex_exit(&msp->ms_lock);
2279                 }
2280 
2281                 metaslab_group_histogram_verify(mg);
2282                 metaslab_class_histogram_verify(mg->mg_class);
2283                 for (int i = 0; i < RANGE_TREE_HISTOGRAM_SIZE; i++)
2284                         ASSERT0(mg->mg_histogram[i]);
2285 
2286         }
2287 
2288         if (vd->vdev_ms_array) {
2289                 (void) dmu_object_free(mos, vd->vdev_ms_array, tx);
2290                 vd->vdev_ms_array = 0;
2291         }
2292 
2293         if (vd->vdev_islog && vd->vdev_top_zap != 0) {
2294                 vdev_destroy_unlink_zap(vd, vd->vdev_top_zap, tx);
2295                 vd->vdev_top_zap = 0;
2296         }
2297         dmu_tx_commit(tx);
2298 }
2299 
2300 void
2301 vdev_sync_done(vdev_t *vd, uint64_t txg)
2302 {
2303         metaslab_t *msp;
2304         boolean_t reassess = !txg_list_empty(&vd->vdev_ms_list, TXG_CLEAN(txg));
2305 
2306         ASSERT(!vd->vdev_ishole);
2307 
2308         while (msp = txg_list_remove(&vd->vdev_ms_list, TXG_CLEAN(txg)))
2309                 metaslab_sync_done(msp, txg);
2310 
2311         if (reassess)
2312                 metaslab_sync_reassess(vd->vdev_mg);
2313 }
2314 
2315 void
2316 vdev_sync(vdev_t *vd, uint64_t txg)
2317 {
2318         spa_t *spa = vd->vdev_spa;
2319         vdev_t *lvd;
2320         metaslab_t *msp;
2321         dmu_tx_t *tx;
2322 
2323         ASSERT(!vd->vdev_ishole);
2324 
2325         if (vd->vdev_ms_array == 0 && vd->vdev_ms_shift != 0) {
2326                 ASSERT(vd == vd->vdev_top);
2327                 tx = dmu_tx_create_assigned(spa->spa_dsl_pool, txg);
2328                 vd->vdev_ms_array = dmu_object_alloc(spa->spa_meta_objset,
2329                     DMU_OT_OBJECT_ARRAY, 0, DMU_OT_NONE, 0, tx);
2330                 ASSERT(vd->vdev_ms_array != 0);
2331                 vdev_config_dirty(vd);
2332                 dmu_tx_commit(tx);
2333         }
2334 
2335         /*
2336          * Remove the metadata associated with this vdev once it's empty.
2337          */
2338         if (vd->vdev_stat.vs_alloc == 0 && vd->vdev_removing)
2339                 vdev_remove(vd, txg);
2340 
2341         while ((msp = txg_list_remove(&vd->vdev_ms_list, txg)) != NULL) {
2342                 metaslab_sync(msp, txg);
2343                 (void) txg_list_add(&vd->vdev_ms_list, msp, TXG_CLEAN(txg));
2344         }
2345 
2346         while ((lvd = txg_list_remove(&vd->vdev_dtl_list, txg)) != NULL)
2347                 vdev_dtl_sync(lvd, txg);
2348 
2349         (void) txg_list_add(&spa->spa_vdev_txg_list, vd, TXG_CLEAN(txg));
2350 }
2351 
2352 uint64_t
2353 vdev_psize_to_asize(vdev_t *vd, uint64_t psize)
2354 {
2355         return (vd->vdev_ops->vdev_op_asize(vd, psize));
2356 }
2357 
2358 /*
2359  * Mark the given vdev faulted.  A faulted vdev behaves as if the device could
2360  * not be opened, and no I/O is attempted.
2361  */
2362 int
2363 vdev_fault(spa_t *spa, uint64_t guid, vdev_aux_t aux)
2364 {
2365         vdev_t *vd, *tvd;
2366 
2367         spa_vdev_state_enter(spa, SCL_NONE);
2368 
2369         if ((vd = spa_lookup_by_guid(spa, guid, B_TRUE)) == NULL)
2370                 return (spa_vdev_state_exit(spa, NULL, ENODEV));
2371 
2372         if (!vd->vdev_ops->vdev_op_leaf)
2373                 return (spa_vdev_state_exit(spa, NULL, ENOTSUP));
2374 
2375         tvd = vd->vdev_top;
2376 
2377         /*
2378          * We don't directly use the aux state here, but if we do a
2379          * vdev_reopen(), we need this value to be present to remember why we
2380          * were faulted.
2381          */
2382         vd->vdev_label_aux = aux;
2383 
2384         /*
2385          * Faulted state takes precedence over degraded.
2386          */
2387         vd->vdev_delayed_close = B_FALSE;
2388         vd->vdev_faulted = 1ULL;
2389         vd->vdev_degraded = 0ULL;
2390         vdev_set_state(vd, B_FALSE, VDEV_STATE_FAULTED, aux);
2391 
2392         /*
2393          * If this device has the only valid copy of the data, then
2394          * back off and simply mark the vdev as degraded instead.
2395          */
2396         if (!tvd->vdev_islog && vd->vdev_aux == NULL && vdev_dtl_required(vd)) {
2397                 vd->vdev_degraded = 1ULL;
2398                 vd->vdev_faulted = 0ULL;
2399 
2400                 /*
2401                  * If we reopen the device and it's not dead, only then do we
2402                  * mark it degraded.
2403                  */
2404                 vdev_reopen(tvd);
2405 
2406                 if (vdev_readable(vd))
2407                         vdev_set_state(vd, B_FALSE, VDEV_STATE_DEGRADED, aux);
2408         }
2409 
2410         return (spa_vdev_state_exit(spa, vd, 0));
2411 }
2412 
2413 /*
2414  * Mark the given vdev degraded.  A degraded vdev is purely an indication to the
2415  * user that something is wrong.  The vdev continues to operate as normal as far
2416  * as I/O is concerned.
2417  */
2418 int
2419 vdev_degrade(spa_t *spa, uint64_t guid, vdev_aux_t aux)
2420 {
2421         vdev_t *vd;
2422 
2423         spa_vdev_state_enter(spa, SCL_NONE);
2424 
2425         if ((vd = spa_lookup_by_guid(spa, guid, B_TRUE)) == NULL)
2426                 return (spa_vdev_state_exit(spa, NULL, ENODEV));
2427 
2428         if (!vd->vdev_ops->vdev_op_leaf)
2429                 return (spa_vdev_state_exit(spa, NULL, ENOTSUP));
2430 
2431         /*
2432          * If the vdev is already faulted, then don't do anything.
2433          */
2434         if (vd->vdev_faulted || vd->vdev_degraded)
2435                 return (spa_vdev_state_exit(spa, NULL, 0));
2436 
2437         vd->vdev_degraded = 1ULL;
2438         if (!vdev_is_dead(vd))
2439                 vdev_set_state(vd, B_FALSE, VDEV_STATE_DEGRADED,
2440                     aux);
2441 
2442         return (spa_vdev_state_exit(spa, vd, 0));
2443 }
2444 
2445 /*
2446  * Online the given vdev.
2447  *
2448  * If 'ZFS_ONLINE_UNSPARE' is set, it implies two things.  First, any attached
2449  * spare device should be detached when the device finishes resilvering.
2450  * Second, the online should be treated like a 'test' online case, so no FMA
2451  * events are generated if the device fails to open.
2452  */
2453 int
2454 vdev_online(spa_t *spa, uint64_t guid, uint64_t flags, vdev_state_t *newstate)
2455 {
2456         vdev_t *vd, *tvd, *pvd, *rvd = spa->spa_root_vdev;
2457         boolean_t wasoffline;
2458         vdev_state_t oldstate;
2459 
2460         spa_vdev_state_enter(spa, SCL_NONE);
2461 
2462         if ((vd = spa_lookup_by_guid(spa, guid, B_TRUE)) == NULL)
2463                 return (spa_vdev_state_exit(spa, NULL, ENODEV));
2464 
2465         if (!vd->vdev_ops->vdev_op_leaf)
2466                 return (spa_vdev_state_exit(spa, NULL, ENOTSUP));
2467 
2468         wasoffline = (vd->vdev_offline || vd->vdev_tmpoffline);
2469         oldstate = vd->vdev_state;
2470 
2471         tvd = vd->vdev_top;
2472         vd->vdev_offline = B_FALSE;
2473         vd->vdev_tmpoffline = B_FALSE;
2474         vd->vdev_checkremove = !!(flags & ZFS_ONLINE_CHECKREMOVE);
2475         vd->vdev_forcefault = !!(flags & ZFS_ONLINE_FORCEFAULT);
2476 
2477         /* XXX - L2ARC 1.0 does not support expansion */
2478         if (!vd->vdev_aux) {
2479                 for (pvd = vd; pvd != rvd; pvd = pvd->vdev_parent)
2480                         pvd->vdev_expanding = !!(flags & ZFS_ONLINE_EXPAND);
2481         }
2482 
2483         vdev_reopen(tvd);
2484         vd->vdev_checkremove = vd->vdev_forcefault = B_FALSE;
2485 
2486         if (!vd->vdev_aux) {
2487                 for (pvd = vd; pvd != rvd; pvd = pvd->vdev_parent)
2488                         pvd->vdev_expanding = B_FALSE;
2489         }
2490 
2491         if (newstate)
2492                 *newstate = vd->vdev_state;
2493         if ((flags & ZFS_ONLINE_UNSPARE) &&
2494             !vdev_is_dead(vd) && vd->vdev_parent &&
2495             vd->vdev_parent->vdev_ops == &vdev_spare_ops &&
2496             vd->vdev_parent->vdev_child[0] == vd)
2497                 vd->vdev_unspare = B_TRUE;
2498 
2499         if ((flags & ZFS_ONLINE_EXPAND) || spa->spa_autoexpand) {
2500 
2501                 /* XXX - L2ARC 1.0 does not support expansion */
2502                 if (vd->vdev_aux)
2503                         return (spa_vdev_state_exit(spa, vd, ENOTSUP));
2504                 spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
2505         }
2506 
2507         if (wasoffline ||
2508             (oldstate < VDEV_STATE_DEGRADED &&
2509             vd->vdev_state >= VDEV_STATE_DEGRADED))
2510                 spa_event_notify(spa, vd, NULL, ESC_ZFS_VDEV_ONLINE);
2511 
2512         return (spa_vdev_state_exit(spa, vd, 0));
2513 }
2514 
2515 static int
2516 vdev_offline_locked(spa_t *spa, uint64_t guid, uint64_t flags)
2517 {
2518         vdev_t *vd, *tvd;
2519         int error = 0;
2520         uint64_t generation;
2521         metaslab_group_t *mg;
2522 
2523 top:
2524         spa_vdev_state_enter(spa, SCL_ALLOC);
2525 
2526         if ((vd = spa_lookup_by_guid(spa, guid, B_TRUE)) == NULL)
2527                 return (spa_vdev_state_exit(spa, NULL, ENODEV));
2528 
2529         if (!vd->vdev_ops->vdev_op_leaf)
2530                 return (spa_vdev_state_exit(spa, NULL, ENOTSUP));
2531 
2532         tvd = vd->vdev_top;
2533         mg = tvd->vdev_mg;
2534         generation = spa->spa_config_generation + 1;
2535 
2536         /*
2537          * If the device isn't already offline, try to offline it.
2538          */
2539         if (!vd->vdev_offline) {
2540                 /*
2541                  * If this device has the only valid copy of some data,
2542                  * don't allow it to be offlined. Log devices are always
2543                  * expendable.
2544                  */
2545                 if (!tvd->vdev_islog && vd->vdev_aux == NULL &&
2546                     vdev_dtl_required(vd))
2547                         return (spa_vdev_state_exit(spa, NULL, EBUSY));
2548 
2549                 /*
2550                  * If the top-level is a slog and it has had allocations
2551                  * then proceed.  We check that the vdev's metaslab group
2552                  * is not NULL since it's possible that we may have just
2553                  * added this vdev but not yet initialized its metaslabs.
2554                  */
2555                 if (tvd->vdev_islog && mg != NULL) {
2556                         /*
2557                          * Prevent any future allocations.
2558                          */
2559                         metaslab_group_passivate(mg);
2560                         (void) spa_vdev_state_exit(spa, vd, 0);
2561 
2562                         error = spa_offline_log(spa);
2563 
2564                         spa_vdev_state_enter(spa, SCL_ALLOC);
2565 
2566                         /*
2567                          * Check to see if the config has changed.
2568                          */
2569                         if (error || generation != spa->spa_config_generation) {
2570                                 metaslab_group_activate(mg);
2571                                 if (error)
2572                                         return (spa_vdev_state_exit(spa,
2573                                             vd, error));
2574                                 (void) spa_vdev_state_exit(spa, vd, 0);
2575                                 goto top;
2576                         }
2577                         ASSERT0(tvd->vdev_stat.vs_alloc);
2578                 }
2579 
2580                 /*
2581                  * Offline this device and reopen its top-level vdev.
2582                  * If the top-level vdev is a log device then just offline
2583                  * it. Otherwise, if this action results in the top-level
2584                  * vdev becoming unusable, undo it and fail the request.
2585                  */
2586                 vd->vdev_offline = B_TRUE;
2587                 vdev_reopen(tvd);
2588 
2589                 if (!tvd->vdev_islog && vd->vdev_aux == NULL &&
2590                     vdev_is_dead(tvd)) {
2591                         vd->vdev_offline = B_FALSE;
2592                         vdev_reopen(tvd);
2593                         return (spa_vdev_state_exit(spa, NULL, EBUSY));
2594                 }
2595 
2596                 /*
2597                  * Add the device back into the metaslab rotor so that
2598                  * once we online the device it's open for business.
2599                  */
2600                 if (tvd->vdev_islog && mg != NULL)
2601                         metaslab_group_activate(mg);
2602         }
2603 
2604         vd->vdev_tmpoffline = !!(flags & ZFS_OFFLINE_TEMPORARY);
2605 
2606         return (spa_vdev_state_exit(spa, vd, 0));
2607 }
2608 
2609 int
2610 vdev_offline(spa_t *spa, uint64_t guid, uint64_t flags)
2611 {
2612         int error;
2613 
2614         mutex_enter(&spa->spa_vdev_top_lock);
2615         error = vdev_offline_locked(spa, guid, flags);
2616         mutex_exit(&spa->spa_vdev_top_lock);
2617 
2618         return (error);
2619 }
2620 
2621 /*
2622  * Clear the error counts associated with this vdev.  Unlike vdev_online() and
2623  * vdev_offline(), we assume the spa config is locked.  We also clear all
2624  * children.  If 'vd' is NULL, then the user wants to clear all vdevs.
2625  */
2626 void
2627 vdev_clear(spa_t *spa, vdev_t *vd)
2628 {
2629         vdev_t *rvd = spa->spa_root_vdev;
2630 
2631         ASSERT(spa_config_held(spa, SCL_STATE_ALL, RW_WRITER) == SCL_STATE_ALL);
2632 
2633         if (vd == NULL)
2634                 vd = rvd;
2635 
2636         vd->vdev_stat.vs_read_errors = 0;
2637         vd->vdev_stat.vs_write_errors = 0;
2638         vd->vdev_stat.vs_checksum_errors = 0;
2639 
2640         for (int c = 0; c < vd->vdev_children; c++)
2641                 vdev_clear(spa, vd->vdev_child[c]);
2642 
2643         /*
2644          * If we're in the FAULTED state or have experienced failed I/O, then
2645          * clear the persistent state and attempt to reopen the device.  We
2646          * also mark the vdev config dirty, so that the new faulted state is
2647          * written out to disk.
2648          */
2649         if (vd->vdev_faulted || vd->vdev_degraded ||
2650             !vdev_readable(vd) || !vdev_writeable(vd)) {
2651 
2652                 /*
2653                  * When reopening in reponse to a clear event, it may be due to
2654                  * a fmadm repair request.  In this case, if the device is
2655                  * still broken, we want to still post the ereport again.
2656                  */
2657                 vd->vdev_forcefault = B_TRUE;
2658 
2659                 vd->vdev_faulted = vd->vdev_degraded = 0ULL;
2660                 vd->vdev_cant_read = B_FALSE;
2661                 vd->vdev_cant_write = B_FALSE;
2662 
2663                 vdev_reopen(vd == rvd ? rvd : vd->vdev_top);
2664 
2665                 vd->vdev_forcefault = B_FALSE;
2666 
2667                 if (vd != rvd && vdev_writeable(vd->vdev_top))
2668                         vdev_state_dirty(vd->vdev_top);
2669 
2670                 if (vd->vdev_aux == NULL && !vdev_is_dead(vd))
2671                         spa_async_request(spa, SPA_ASYNC_RESILVER);
2672 
2673                 spa_event_notify(spa, vd, NULL, ESC_ZFS_VDEV_CLEAR);
2674         }
2675 
2676         /*
2677          * When clearing a FMA-diagnosed fault, we always want to
2678          * unspare the device, as we assume that the original spare was
2679          * done in response to the FMA fault.
2680          */
2681         if (!vdev_is_dead(vd) && vd->vdev_parent != NULL &&
2682             vd->vdev_parent->vdev_ops == &vdev_spare_ops &&
2683             vd->vdev_parent->vdev_child[0] == vd)
2684                 vd->vdev_unspare = B_TRUE;
2685 }
2686 
2687 boolean_t
2688 vdev_is_dead(vdev_t *vd)
2689 {
2690         /*
2691          * Holes and missing devices are always considered "dead".
2692          * This simplifies the code since we don't have to check for
2693          * these types of devices in the various code paths.
2694          * Instead we rely on the fact that we skip over dead devices
2695          * before issuing I/O to them.
2696          */
2697         return (vd->vdev_state < VDEV_STATE_DEGRADED || vd->vdev_ishole ||
2698             vd->vdev_ops == &vdev_missing_ops);
2699 }
2700 
2701 boolean_t
2702 vdev_readable(vdev_t *vd)
2703 {
2704         return (!vdev_is_dead(vd) && !vd->vdev_cant_read);
2705 }
2706 
2707 boolean_t
2708 vdev_writeable(vdev_t *vd)
2709 {
2710         return (!vdev_is_dead(vd) && !vd->vdev_cant_write);
2711 }
2712 
2713 boolean_t
2714 vdev_allocatable(vdev_t *vd)
2715 {
2716         uint64_t state = vd->vdev_state;
2717 
2718         /*
2719          * We currently allow allocations from vdevs which may be in the
2720          * process of reopening (i.e. VDEV_STATE_CLOSED). If the device
2721          * fails to reopen then we'll catch it later when we're holding
2722          * the proper locks.  Note that we have to get the vdev state
2723          * in a local variable because although it changes atomically,
2724          * we're asking two separate questions about it.
2725          */
2726         return (!(state < VDEV_STATE_DEGRADED && state != VDEV_STATE_CLOSED) &&
2727             !vd->vdev_cant_write && !vd->vdev_ishole &&
2728             vd->vdev_mg->mg_initialized);
2729 }
2730 
2731 boolean_t
2732 vdev_accessible(vdev_t *vd, zio_t *zio)
2733 {
2734         ASSERT(zio->io_vd == vd);
2735 
2736         if (vdev_is_dead(vd) || vd->vdev_remove_wanted)
2737                 return (B_FALSE);
2738 
2739         if (zio->io_type == ZIO_TYPE_READ)
2740                 return (!vd->vdev_cant_read);
2741 
2742         if (zio->io_type == ZIO_TYPE_WRITE)
2743                 return (!vd->vdev_cant_write);
2744 
2745         return (B_TRUE);
2746 }
2747 
2748 /*
2749  * Get statistics for the given vdev.
2750  */
2751 void
2752 vdev_get_stats(vdev_t *vd, vdev_stat_t *vs)
2753 {
2754         spa_t *spa = vd->vdev_spa;
2755         vdev_t *rvd = spa->spa_root_vdev;
2756         vdev_t *tvd = vd->vdev_top;
2757 
2758         ASSERT(spa_config_held(spa, SCL_ALL, RW_READER) != 0);
2759 
2760         mutex_enter(&vd->vdev_stat_lock);
2761         bcopy(&vd->vdev_stat, vs, sizeof (*vs));
2762         vs->vs_timestamp = gethrtime() - vs->vs_timestamp;
2763         vs->vs_state = vd->vdev_state;
2764         vs->vs_rsize = vdev_get_min_asize(vd);
2765         if (vd->vdev_ops->vdev_op_leaf)
2766                 vs->vs_rsize += VDEV_LABEL_START_SIZE + VDEV_LABEL_END_SIZE;
2767         /*
2768          * Report expandable space on top-level, non-auxillary devices only.
2769          * The expandable space is reported in terms of metaslab sized units
2770          * since that determines how much space the pool can expand.
2771          */
2772         if (vd->vdev_aux == NULL && tvd != NULL) {
2773                 vs->vs_esize = P2ALIGN(vd->vdev_max_asize - vd->vdev_asize -
2774                     spa->spa_bootsize, 1ULL << tvd->vdev_ms_shift);
2775         }
2776         if (vd->vdev_aux == NULL && vd == vd->vdev_top && !vd->vdev_ishole) {
2777                 vs->vs_fragmentation = vd->vdev_mg->mg_fragmentation;
2778         }
2779 
2780         /*
2781          * If we're getting stats on the root vdev, aggregate the I/O counts
2782          * over all top-level vdevs (i.e. the direct children of the root).
2783          */
2784         if (vd == rvd) {
2785                 for (int c = 0; c < rvd->vdev_children; c++) {
2786                         vdev_t *cvd = rvd->vdev_child[c];
2787                         vdev_stat_t *cvs = &cvd->vdev_stat;
2788 
2789                         for (int t = 0; t < ZIO_TYPES; t++) {
2790                                 vs->vs_ops[t] += cvs->vs_ops[t];
2791                                 vs->vs_bytes[t] += cvs->vs_bytes[t];
2792                         }
2793                         cvs->vs_scan_removing = cvd->vdev_removing;
2794                 }
2795         }
2796         mutex_exit(&vd->vdev_stat_lock);
2797 }
2798 
2799 void
2800 vdev_clear_stats(vdev_t *vd)
2801 {
2802         mutex_enter(&vd->vdev_stat_lock);
2803         vd->vdev_stat.vs_space = 0;
2804         vd->vdev_stat.vs_dspace = 0;
2805         vd->vdev_stat.vs_alloc = 0;
2806         mutex_exit(&vd->vdev_stat_lock);
2807 }
2808 
2809 void
2810 vdev_scan_stat_init(vdev_t *vd)
2811 {
2812         vdev_stat_t *vs = &vd->vdev_stat;
2813 
2814         for (int c = 0; c < vd->vdev_children; c++)
2815                 vdev_scan_stat_init(vd->vdev_child[c]);
2816 
2817         mutex_enter(&vd->vdev_stat_lock);
2818         vs->vs_scan_processed = 0;
2819         mutex_exit(&vd->vdev_stat_lock);
2820 }
2821 
2822 void
2823 vdev_stat_update(zio_t *zio, uint64_t psize)
2824 {
2825         spa_t *spa = zio->io_spa;
2826         vdev_t *rvd = spa->spa_root_vdev;
2827         vdev_t *vd = zio->io_vd ? zio->io_vd : rvd;
2828         vdev_t *pvd;
2829         uint64_t txg = zio->io_txg;
2830         vdev_stat_t *vs = &vd->vdev_stat;
2831         zio_type_t type = zio->io_type;
2832         int flags = zio->io_flags;
2833 
2834         /*
2835          * If this i/o is a gang leader, it didn't do any actual work.
2836          */
2837         if (zio->io_gang_tree)
2838                 return;
2839 
2840         if (zio->io_error == 0) {
2841                 /*
2842                  * If this is a root i/o, don't count it -- we've already
2843                  * counted the top-level vdevs, and vdev_get_stats() will
2844                  * aggregate them when asked.  This reduces contention on
2845                  * the root vdev_stat_lock and implicitly handles blocks
2846                  * that compress away to holes, for which there is no i/o.
2847                  * (Holes never create vdev children, so all the counters
2848                  * remain zero, which is what we want.)
2849                  *
2850                  * Note: this only applies to successful i/o (io_error == 0)
2851                  * because unlike i/o counts, errors are not additive.
2852                  * When reading a ditto block, for example, failure of
2853                  * one top-level vdev does not imply a root-level error.
2854                  */
2855                 if (vd == rvd)
2856                         return;
2857 
2858                 ASSERT(vd == zio->io_vd);
2859 
2860                 if (flags & ZIO_FLAG_IO_BYPASS)
2861                         return;
2862 
2863                 mutex_enter(&vd->vdev_stat_lock);
2864 
2865                 if (flags & ZIO_FLAG_IO_REPAIR) {
2866                         if (flags & ZIO_FLAG_SCAN_THREAD) {
2867                                 dsl_scan_phys_t *scn_phys =
2868                                     &spa->spa_dsl_pool->dp_scan->scn_phys;
2869                                 uint64_t *processed = &scn_phys->scn_processed;
2870 
2871                                 /* XXX cleanup? */
2872                                 if (vd->vdev_ops->vdev_op_leaf)
2873                                         atomic_add_64(processed, psize);
2874                                 vs->vs_scan_processed += psize;
2875                         }
2876 
2877                         if (flags & ZIO_FLAG_SELF_HEAL)
2878                                 vs->vs_self_healed += psize;
2879                 }
2880 
2881                 vs->vs_ops[type]++;
2882                 vs->vs_bytes[type] += psize;
2883 
2884                 mutex_exit(&vd->vdev_stat_lock);
2885                 return;
2886         }
2887 
2888         if (flags & ZIO_FLAG_SPECULATIVE)
2889                 return;
2890 
2891         /*
2892          * If this is an I/O error that is going to be retried, then ignore the
2893          * error.  Otherwise, the user may interpret B_FAILFAST I/O errors as
2894          * hard errors, when in reality they can happen for any number of
2895          * innocuous reasons (bus resets, MPxIO link failure, etc).
2896          */
2897         if (zio->io_error == EIO &&
2898             !(zio->io_flags & ZIO_FLAG_IO_RETRY))
2899                 return;
2900 
2901         /*
2902          * Intent logs writes won't propagate their error to the root
2903          * I/O so don't mark these types of failures as pool-level
2904          * errors.
2905          */
2906         if (zio->io_vd == NULL && (zio->io_flags & ZIO_FLAG_DONT_PROPAGATE))
2907                 return;
2908 
2909         mutex_enter(&vd->vdev_stat_lock);
2910         if (type == ZIO_TYPE_READ && !vdev_is_dead(vd)) {
2911                 if (zio->io_error == ECKSUM)
2912                         vs->vs_checksum_errors++;
2913                 else
2914                         vs->vs_read_errors++;
2915         }
2916         if (type == ZIO_TYPE_WRITE && !vdev_is_dead(vd))
2917                 vs->vs_write_errors++;
2918         mutex_exit(&vd->vdev_stat_lock);
2919 
2920         if (type == ZIO_TYPE_WRITE && txg != 0 &&
2921             (!(flags & ZIO_FLAG_IO_REPAIR) ||
2922             (flags & ZIO_FLAG_SCAN_THREAD) ||
2923             spa->spa_claiming)) {
2924                 /*
2925                  * This is either a normal write (not a repair), or it's
2926                  * a repair induced by the scrub thread, or it's a repair
2927                  * made by zil_claim() during spa_load() in the first txg.
2928                  * In the normal case, we commit the DTL change in the same
2929                  * txg as the block was born.  In the scrub-induced repair
2930                  * case, we know that scrubs run in first-pass syncing context,
2931                  * so we commit the DTL change in spa_syncing_txg(spa).
2932                  * In the zil_claim() case, we commit in spa_first_txg(spa).
2933                  *
2934                  * We currently do not make DTL entries for failed spontaneous
2935                  * self-healing writes triggered by normal (non-scrubbing)
2936                  * reads, because we have no transactional context in which to
2937                  * do so -- and it's not clear that it'd be desirable anyway.
2938                  */
2939                 if (vd->vdev_ops->vdev_op_leaf) {
2940                         uint64_t commit_txg = txg;
2941                         if (flags & ZIO_FLAG_SCAN_THREAD) {
2942                                 ASSERT(flags & ZIO_FLAG_IO_REPAIR);
2943                                 ASSERT(spa_sync_pass(spa) == 1);
2944                                 vdev_dtl_dirty(vd, DTL_SCRUB, txg, 1);
2945                                 commit_txg = spa_syncing_txg(spa);
2946                         } else if (spa->spa_claiming) {
2947                                 ASSERT(flags & ZIO_FLAG_IO_REPAIR);
2948                                 commit_txg = spa_first_txg(spa);
2949                         }
2950                         ASSERT(commit_txg >= spa_syncing_txg(spa));
2951                         if (vdev_dtl_contains(vd, DTL_MISSING, txg, 1))
2952                                 return;
2953                         for (pvd = vd; pvd != rvd; pvd = pvd->vdev_parent)
2954                                 vdev_dtl_dirty(pvd, DTL_PARTIAL, txg, 1);
2955                         vdev_dirty(vd->vdev_top, VDD_DTL, vd, commit_txg);
2956                 }
2957                 if (vd != rvd)
2958                         vdev_dtl_dirty(vd, DTL_MISSING, txg, 1);
2959         }
2960 }
2961 
2962 /*
2963  * Update the in-core space usage stats for this vdev, its metaslab class,
2964  * and the root vdev.
2965  */
2966 void
2967 vdev_space_update(vdev_t *vd, int64_t alloc_delta, int64_t defer_delta,
2968     int64_t space_delta)
2969 {
2970         int64_t dspace_delta = space_delta;
2971         spa_t *spa = vd->vdev_spa;
2972         vdev_t *rvd = spa->spa_root_vdev;
2973         metaslab_group_t *mg = vd->vdev_mg;
2974         metaslab_class_t *mc = mg ? mg->mg_class : NULL;
2975 
2976         ASSERT(vd == vd->vdev_top);
2977 
2978         /*
2979          * Apply the inverse of the psize-to-asize (ie. RAID-Z) space-expansion
2980          * factor.  We must calculate this here and not at the root vdev
2981          * because the root vdev's psize-to-asize is simply the max of its
2982          * childrens', thus not accurate enough for us.
2983          */
2984         ASSERT((dspace_delta & (SPA_MINBLOCKSIZE-1)) == 0);
2985         ASSERT(vd->vdev_deflate_ratio != 0 || vd->vdev_isl2cache);
2986         dspace_delta = (dspace_delta >> SPA_MINBLOCKSHIFT) *
2987             vd->vdev_deflate_ratio;
2988 
2989         mutex_enter(&vd->vdev_stat_lock);
2990         vd->vdev_stat.vs_alloc += alloc_delta;
2991         vd->vdev_stat.vs_space += space_delta;
2992         vd->vdev_stat.vs_dspace += dspace_delta;
2993         mutex_exit(&vd->vdev_stat_lock);
2994 
2995         if (mc == spa_normal_class(spa)) {
2996                 mutex_enter(&rvd->vdev_stat_lock);
2997                 rvd->vdev_stat.vs_alloc += alloc_delta;
2998                 rvd->vdev_stat.vs_space += space_delta;
2999                 rvd->vdev_stat.vs_dspace += dspace_delta;
3000                 mutex_exit(&rvd->vdev_stat_lock);
3001         }
3002 
3003         if (mc != NULL) {
3004                 ASSERT(rvd == vd->vdev_parent);
3005                 ASSERT(vd->vdev_ms_count != 0);
3006 
3007                 metaslab_class_space_update(mc,
3008                     alloc_delta, defer_delta, space_delta, dspace_delta);
3009         }
3010 }
3011 
3012 /*
3013  * Mark a top-level vdev's config as dirty, placing it on the dirty list
3014  * so that it will be written out next time the vdev configuration is synced.
3015  * If the root vdev is specified (vdev_top == NULL), dirty all top-level vdevs.
3016  */
3017 void
3018 vdev_config_dirty(vdev_t *vd)
3019 {
3020         spa_t *spa = vd->vdev_spa;
3021         vdev_t *rvd = spa->spa_root_vdev;
3022         int c;
3023 
3024         ASSERT(spa_writeable(spa));
3025 
3026         /*
3027          * If this is an aux vdev (as with l2cache and spare devices), then we
3028          * update the vdev config manually and set the sync flag.
3029          */
3030         if (vd->vdev_aux != NULL) {
3031                 spa_aux_vdev_t *sav = vd->vdev_aux;
3032                 nvlist_t **aux;
3033                 uint_t naux;
3034 
3035                 for (c = 0; c < sav->sav_count; c++) {
3036                         if (sav->sav_vdevs[c] == vd)
3037                                 break;
3038                 }
3039 
3040                 if (c == sav->sav_count) {
3041                         /*
3042                          * We're being removed.  There's nothing more to do.
3043                          */
3044                         ASSERT(sav->sav_sync == B_TRUE);
3045                         return;
3046                 }
3047 
3048                 sav->sav_sync = B_TRUE;
3049 
3050                 if (nvlist_lookup_nvlist_array(sav->sav_config,
3051                     ZPOOL_CONFIG_L2CACHE, &aux, &naux) != 0) {
3052                         VERIFY(nvlist_lookup_nvlist_array(sav->sav_config,
3053                             ZPOOL_CONFIG_SPARES, &aux, &naux) == 0);
3054                 }
3055 
3056                 ASSERT(c < naux);
3057 
3058                 /*
3059                  * Setting the nvlist in the middle if the array is a little
3060                  * sketchy, but it will work.
3061                  */
3062                 nvlist_free(aux[c]);
3063                 aux[c] = vdev_config_generate(spa, vd, B_TRUE, 0);
3064 
3065                 return;
3066         }
3067 
3068         /*
3069          * The dirty list is protected by the SCL_CONFIG lock.  The caller
3070          * must either hold SCL_CONFIG as writer, or must be the sync thread
3071          * (which holds SCL_CONFIG as reader).  There's only one sync thread,
3072          * so this is sufficient to ensure mutual exclusion.
3073          */
3074         ASSERT(spa_config_held(spa, SCL_CONFIG, RW_WRITER) ||
3075             (dsl_pool_sync_context(spa_get_dsl(spa)) &&
3076             spa_config_held(spa, SCL_CONFIG, RW_READER)));
3077 
3078         if (vd == rvd) {
3079                 for (c = 0; c < rvd->vdev_children; c++)
3080                         vdev_config_dirty(rvd->vdev_child[c]);
3081         } else {
3082                 ASSERT(vd == vd->vdev_top);
3083 
3084                 if (!list_link_active(&vd->vdev_config_dirty_node) &&
3085                     !vd->vdev_ishole)
3086                         list_insert_head(&spa->spa_config_dirty_list, vd);
3087         }
3088 }
3089 
3090 void
3091 vdev_config_clean(vdev_t *vd)
3092 {
3093         spa_t *spa = vd->vdev_spa;
3094 
3095         ASSERT(spa_config_held(spa, SCL_CONFIG, RW_WRITER) ||
3096             (dsl_pool_sync_context(spa_get_dsl(spa)) &&
3097             spa_config_held(spa, SCL_CONFIG, RW_READER)));
3098 
3099         ASSERT(list_link_active(&vd->vdev_config_dirty_node));
3100         list_remove(&spa->spa_config_dirty_list, vd);
3101 }
3102 
3103 /*
3104  * Mark a top-level vdev's state as dirty, so that the next pass of
3105  * spa_sync() can convert this into vdev_config_dirty().  We distinguish
3106  * the state changes from larger config changes because they require
3107  * much less locking, and are often needed for administrative actions.
3108  */
3109 void
3110 vdev_state_dirty(vdev_t *vd)
3111 {
3112         spa_t *spa = vd->vdev_spa;
3113 
3114         ASSERT(spa_writeable(spa));
3115         ASSERT(vd == vd->vdev_top);
3116 
3117         /*
3118          * The state list is protected by the SCL_STATE lock.  The caller
3119          * must either hold SCL_STATE as writer, or must be the sync thread
3120          * (which holds SCL_STATE as reader).  There's only one sync thread,
3121          * so this is sufficient to ensure mutual exclusion.
3122          */
3123         ASSERT(spa_config_held(spa, SCL_STATE, RW_WRITER) ||
3124             (dsl_pool_sync_context(spa_get_dsl(spa)) &&
3125             spa_config_held(spa, SCL_STATE, RW_READER)));
3126 
3127         if (!list_link_active(&vd->vdev_state_dirty_node) && !vd->vdev_ishole)
3128                 list_insert_head(&spa->spa_state_dirty_list, vd);
3129 }
3130 
3131 void
3132 vdev_state_clean(vdev_t *vd)
3133 {
3134         spa_t *spa = vd->vdev_spa;
3135 
3136         ASSERT(spa_config_held(spa, SCL_STATE, RW_WRITER) ||
3137             (dsl_pool_sync_context(spa_get_dsl(spa)) &&
3138             spa_config_held(spa, SCL_STATE, RW_READER)));
3139 
3140         ASSERT(list_link_active(&vd->vdev_state_dirty_node));
3141         list_remove(&spa->spa_state_dirty_list, vd);
3142 }
3143 
3144 /*
3145  * Propagate vdev state up from children to parent.
3146  */
3147 void
3148 vdev_propagate_state(vdev_t *vd)
3149 {
3150         spa_t *spa = vd->vdev_spa;
3151         vdev_t *rvd = spa->spa_root_vdev;
3152         int degraded = 0, faulted = 0;
3153         int corrupted = 0;
3154         vdev_t *child;
3155 
3156         if (vd->vdev_children > 0) {
3157                 for (int c = 0; c < vd->vdev_children; c++) {
3158                         child = vd->vdev_child[c];
3159 
3160                         /*
3161                          * Don't factor holes into the decision.
3162                          */
3163                         if (child->vdev_ishole)
3164                                 continue;
3165 
3166                         if (!vdev_readable(child) ||
3167                             (!vdev_writeable(child) && spa_writeable(spa))) {
3168                                 /*
3169                                  * Root special: if there is a top-level log
3170                                  * device, treat the root vdev as if it were
3171                                  * degraded.
3172                                  */
3173                                 if (child->vdev_islog && vd == rvd)
3174                                         degraded++;
3175                                 else
3176                                         faulted++;
3177                         } else if (child->vdev_state <= VDEV_STATE_DEGRADED) {
3178                                 degraded++;
3179                         }
3180 
3181                         if (child->vdev_stat.vs_aux == VDEV_AUX_CORRUPT_DATA)
3182                                 corrupted++;
3183                 }
3184 
3185                 vd->vdev_ops->vdev_op_state_change(vd, faulted, degraded);
3186 
3187                 /*
3188                  * Root special: if there is a top-level vdev that cannot be
3189                  * opened due to corrupted metadata, then propagate the root
3190                  * vdev's aux state as 'corrupt' rather than 'insufficient
3191                  * replicas'.
3192                  */
3193                 if (corrupted && vd == rvd &&
3194                     rvd->vdev_state == VDEV_STATE_CANT_OPEN)
3195                         vdev_set_state(rvd, B_FALSE, VDEV_STATE_CANT_OPEN,
3196                             VDEV_AUX_CORRUPT_DATA);
3197         }
3198 
3199         if (vd->vdev_parent)
3200                 vdev_propagate_state(vd->vdev_parent);
3201 }
3202 
3203 /*
3204  * Set a vdev's state.  If this is during an open, we don't update the parent
3205  * state, because we're in the process of opening children depth-first.
3206  * Otherwise, we propagate the change to the parent.
3207  *
3208  * If this routine places a device in a faulted state, an appropriate ereport is
3209  * generated.
3210  */
3211 void
3212 vdev_set_state(vdev_t *vd, boolean_t isopen, vdev_state_t state, vdev_aux_t aux)
3213 {
3214         uint64_t save_state;
3215         spa_t *spa = vd->vdev_spa;
3216 
3217         if (state == vd->vdev_state) {
3218                 vd->vdev_stat.vs_aux = aux;
3219                 return;
3220         }
3221 
3222         save_state = vd->vdev_state;
3223 
3224         vd->vdev_state = state;
3225         vd->vdev_stat.vs_aux = aux;
3226 
3227         /*
3228          * If we are setting the vdev state to anything but an open state, then
3229          * always close the underlying device unless the device has requested
3230          * a delayed close (i.e. we're about to remove or fault the device).
3231          * Otherwise, we keep accessible but invalid devices open forever.
3232          * We don't call vdev_close() itself, because that implies some extra
3233          * checks (offline, etc) that we don't want here.  This is limited to
3234          * leaf devices, because otherwise closing the device will affect other
3235          * children.
3236          */
3237         if (!vd->vdev_delayed_close && vdev_is_dead(vd) &&
3238             vd->vdev_ops->vdev_op_leaf)
3239                 vd->vdev_ops->vdev_op_close(vd);
3240 
3241         /*
3242          * If we have brought this vdev back into service, we need
3243          * to notify fmd so that it can gracefully repair any outstanding
3244          * cases due to a missing device.  We do this in all cases, even those
3245          * that probably don't correlate to a repaired fault.  This is sure to
3246          * catch all cases, and we let the zfs-retire agent sort it out.  If
3247          * this is a transient state it's OK, as the retire agent will
3248          * double-check the state of the vdev before repairing it.
3249          */
3250         if (state == VDEV_STATE_HEALTHY && vd->vdev_ops->vdev_op_leaf &&
3251             vd->vdev_prevstate != state)
3252                 zfs_post_state_change(spa, vd);
3253 
3254         if (vd->vdev_removed &&
3255             state == VDEV_STATE_CANT_OPEN &&
3256             (aux == VDEV_AUX_OPEN_FAILED || vd->vdev_checkremove)) {
3257                 /*
3258                  * If the previous state is set to VDEV_STATE_REMOVED, then this
3259                  * device was previously marked removed and someone attempted to
3260                  * reopen it.  If this failed due to a nonexistent device, then
3261                  * keep the device in the REMOVED state.  We also let this be if
3262                  * it is one of our special test online cases, which is only
3263                  * attempting to online the device and shouldn't generate an FMA
3264                  * fault.
3265                  */
3266                 vd->vdev_state = VDEV_STATE_REMOVED;
3267                 vd->vdev_stat.vs_aux = VDEV_AUX_NONE;
3268         } else if (state == VDEV_STATE_REMOVED) {
3269                 vd->vdev_removed = B_TRUE;
3270         } else if (state == VDEV_STATE_CANT_OPEN) {
3271                 /*
3272                  * If we fail to open a vdev during an import or recovery, we
3273                  * mark it as "not available", which signifies that it was
3274                  * never there to begin with.  Failure to open such a device
3275                  * is not considered an error.
3276                  */
3277                 if ((spa_load_state(spa) == SPA_LOAD_IMPORT ||
3278                     spa_load_state(spa) == SPA_LOAD_RECOVER) &&
3279                     vd->vdev_ops->vdev_op_leaf)
3280                         vd->vdev_not_present = 1;
3281 
3282                 /*
3283                  * Post the appropriate ereport.  If the 'prevstate' field is
3284                  * set to something other than VDEV_STATE_UNKNOWN, it indicates
3285                  * that this is part of a vdev_reopen().  In this case, we don't
3286                  * want to post the ereport if the device was already in the
3287                  * CANT_OPEN state beforehand.
3288                  *
3289                  * If the 'checkremove' flag is set, then this is an attempt to
3290                  * online the device in response to an insertion event.  If we
3291                  * hit this case, then we have detected an insertion event for a
3292                  * faulted or offline device that wasn't in the removed state.
3293                  * In this scenario, we don't post an ereport because we are
3294                  * about to replace the device, or attempt an online with
3295                  * vdev_forcefault, which will generate the fault for us.
3296                  */
3297                 if ((vd->vdev_prevstate != state || vd->vdev_forcefault) &&
3298                     !vd->vdev_not_present && !vd->vdev_checkremove &&
3299                     vd != spa->spa_root_vdev) {
3300                         const char *class;
3301 
3302                         switch (aux) {
3303                         case VDEV_AUX_OPEN_FAILED:
3304                                 class = FM_EREPORT_ZFS_DEVICE_OPEN_FAILED;
3305                                 break;
3306                         case VDEV_AUX_CORRUPT_DATA:
3307                                 class = FM_EREPORT_ZFS_DEVICE_CORRUPT_DATA;
3308                                 break;
3309                         case VDEV_AUX_NO_REPLICAS:
3310                                 class = FM_EREPORT_ZFS_DEVICE_NO_REPLICAS;
3311                                 break;
3312                         case VDEV_AUX_BAD_GUID_SUM:
3313                                 class = FM_EREPORT_ZFS_DEVICE_BAD_GUID_SUM;
3314                                 break;
3315                         case VDEV_AUX_TOO_SMALL:
3316                                 class = FM_EREPORT_ZFS_DEVICE_TOO_SMALL;
3317                                 break;
3318                         case VDEV_AUX_BAD_LABEL:
3319                                 class = FM_EREPORT_ZFS_DEVICE_BAD_LABEL;
3320                                 break;
3321                         default:
3322                                 class = FM_EREPORT_ZFS_DEVICE_UNKNOWN;
3323                         }
3324 
3325                         zfs_ereport_post(class, spa, vd, NULL, save_state, 0);
3326                 }
3327 
3328                 /* Erase any notion of persistent removed state */
3329                 vd->vdev_removed = B_FALSE;
3330         } else {
3331                 vd->vdev_removed = B_FALSE;
3332         }
3333 
3334         if (!isopen && vd->vdev_parent)
3335                 vdev_propagate_state(vd->vdev_parent);
3336 }
3337 
3338 /*
3339  * Check the vdev configuration to ensure that it's capable of supporting
3340  * a root pool. We do not support partial configuration.
3341  * In addition, only a single top-level vdev is allowed.
3342  */
3343 boolean_t
3344 vdev_is_bootable(vdev_t *vd)
3345 {
3346         if (!vd->vdev_ops->vdev_op_leaf) {
3347                 char *vdev_type = vd->vdev_ops->vdev_op_type;
3348 
3349                 if (strcmp(vdev_type, VDEV_TYPE_ROOT) == 0 &&
3350                     vd->vdev_children > 1) {
3351                         return (B_FALSE);
3352                 } else if (strcmp(vdev_type, VDEV_TYPE_MISSING) == 0) {
3353                         return (B_FALSE);
3354                 }
3355         }
3356 
3357         for (int c = 0; c < vd->vdev_children; c++) {
3358                 if (!vdev_is_bootable(vd->vdev_child[c]))
3359                         return (B_FALSE);
3360         }
3361         return (B_TRUE);
3362 }
3363 
3364 /*
3365  * Load the state from the original vdev tree (ovd) which
3366  * we've retrieved from the MOS config object. If the original
3367  * vdev was offline or faulted then we transfer that state to the
3368  * device in the current vdev tree (nvd).
3369  */
3370 void
3371 vdev_load_log_state(vdev_t *nvd, vdev_t *ovd)
3372 {
3373         spa_t *spa = nvd->vdev_spa;
3374 
3375         ASSERT(nvd->vdev_top->vdev_islog);
3376         ASSERT(spa_config_held(spa, SCL_STATE_ALL, RW_WRITER) == SCL_STATE_ALL);
3377         ASSERT3U(nvd->vdev_guid, ==, ovd->vdev_guid);
3378 
3379         for (int c = 0; c < nvd->vdev_children; c++)
3380                 vdev_load_log_state(nvd->vdev_child[c], ovd->vdev_child[c]);
3381 
3382         if (nvd->vdev_ops->vdev_op_leaf) {
3383                 /*
3384                  * Restore the persistent vdev state
3385                  */
3386                 nvd->vdev_offline = ovd->vdev_offline;
3387                 nvd->vdev_faulted = ovd->vdev_faulted;
3388                 nvd->vdev_degraded = ovd->vdev_degraded;
3389                 nvd->vdev_removed = ovd->vdev_removed;
3390         }
3391 }
3392 
3393 /*
3394  * Determine if a log device has valid content.  If the vdev was
3395  * removed or faulted in the MOS config then we know that
3396  * the content on the log device has already been written to the pool.
3397  */
3398 boolean_t
3399 vdev_log_state_valid(vdev_t *vd)
3400 {
3401         if (vd->vdev_ops->vdev_op_leaf && !vd->vdev_faulted &&
3402             !vd->vdev_removed)
3403                 return (B_TRUE);
3404 
3405         for (int c = 0; c < vd->vdev_children; c++)
3406                 if (vdev_log_state_valid(vd->vdev_child[c]))
3407                         return (B_TRUE);
3408 
3409         return (B_FALSE);
3410 }
3411 
3412 /*
3413  * Expand a vdev if possible.
3414  */
3415 void
3416 vdev_expand(vdev_t *vd, uint64_t txg)
3417 {
3418         ASSERT(vd->vdev_top == vd);
3419         ASSERT(spa_config_held(vd->vdev_spa, SCL_ALL, RW_WRITER) == SCL_ALL);
3420 
3421         if ((vd->vdev_asize >> vd->vdev_ms_shift) > vd->vdev_ms_count) {
3422                 VERIFY(vdev_metaslab_init(vd, txg) == 0);
3423                 vdev_config_dirty(vd);
3424         }
3425 }
3426 
3427 /*
3428  * Split a vdev.
3429  */
3430 void
3431 vdev_split(vdev_t *vd)
3432 {
3433         vdev_t *cvd, *pvd = vd->vdev_parent;
3434 
3435         vdev_remove_child(pvd, vd);
3436         vdev_compact_children(pvd);
3437 
3438         cvd = pvd->vdev_child[0];
3439         if (pvd->vdev_children == 1) {
3440                 vdev_remove_parent(cvd);
3441                 cvd->vdev_splitting = B_TRUE;
3442         }
3443         vdev_propagate_state(cvd);
3444 }
3445 
3446 void
3447 vdev_deadman(vdev_t *vd)
3448 {
3449         for (int c = 0; c < vd->vdev_children; c++) {
3450                 vdev_t *cvd = vd->vdev_child[c];
3451 
3452                 vdev_deadman(cvd);
3453         }
3454 
3455         if (vd->vdev_ops->vdev_op_leaf) {
3456                 vdev_queue_t *vq = &vd->vdev_queue;
3457 
3458                 mutex_enter(&vq->vq_lock);
3459                 if (avl_numnodes(&vq->vq_active_tree) > 0) {
3460                         spa_t *spa = vd->vdev_spa;
3461                         zio_t *fio;
3462                         uint64_t delta;
3463 
3464                         /*
3465                          * Look at the head of all the pending queues,
3466                          * if any I/O has been outstanding for longer than
3467                          * the spa_deadman_synctime we panic the system.
3468                          */
3469                         fio = avl_first(&vq->vq_active_tree);
3470                         delta = gethrtime() - fio->io_timestamp;
3471                         if (delta > spa_deadman_synctime(spa)) {
3472                                 zfs_dbgmsg("SLOW IO: zio timestamp %lluns, "
3473                                     "delta %lluns, last io %lluns",
3474                                     fio->io_timestamp, delta,
3475                                     vq->vq_io_complete_ts);
3476                                 fm_panic("I/O to pool '%s' appears to be "
3477                                     "hung.", spa_name(spa));
3478                         }
3479                 }
3480                 mutex_exit(&vq->vq_lock);
3481         }
3482 }