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, 2018 by Delphix. All rights reserved. 25 */ 26 27 #include <sys/zfs_context.h> 28 #include <sys/spa_impl.h> 29 #include <sys/dmu.h> 30 #include <sys/dmu_tx.h> 31 #include <sys/zap.h> 32 #include <sys/vdev_impl.h> 33 #include <sys/metaslab.h> 34 #include <sys/metaslab_impl.h> 35 #include <sys/uberblock_impl.h> 36 #include <sys/txg.h> 37 #include <sys/avl.h> 38 #include <sys/bpobj.h> 39 #include <sys/dsl_pool.h> 40 #include <sys/dsl_synctask.h> 41 #include <sys/dsl_dir.h> 42 #include <sys/arc.h> 43 #include <sys/zfeature.h> 44 #include <sys/vdev_indirect_births.h> 45 #include <sys/vdev_indirect_mapping.h> 46 #include <sys/abd.h> 47 #include <sys/vdev_initialize.h> 48 49 /* 50 * This file contains the necessary logic to remove vdevs from a 51 * storage pool. Currently, the only devices that can be removed 52 * are log, cache, and spare devices; and top level vdevs from a pool 53 * w/o raidz. (Note that members of a mirror can also be removed 54 * by the detach operation.) 55 * 56 * Log vdevs are removed by evacuating them and then turning the vdev 57 * into a hole vdev while holding spa config locks. 58 * 59 * Top level vdevs are removed and converted into an indirect vdev via 60 * a multi-step process: 61 * 62 * - Disable allocations from this device (spa_vdev_remove_top). 63 * 64 * - From a new thread (spa_vdev_remove_thread), copy data from 65 * the removing vdev to a different vdev. The copy happens in open 66 * context (spa_vdev_copy_impl) and issues a sync task 67 * (vdev_mapping_sync) so the sync thread can update the partial 68 * indirect mappings in core and on disk. 69 * 70 * - If a free happens during a removal, it is freed from the 71 * removing vdev, and if it has already been copied, from the new 72 * location as well (free_from_removing_vdev). 73 * 74 * - After the removal is completed, the copy thread converts the vdev 75 * into an indirect vdev (vdev_remove_complete) before instructing 76 * the sync thread to destroy the space maps and finish the removal 77 * (spa_finish_removal). 78 */ 79 80 typedef struct vdev_copy_arg { 81 metaslab_t *vca_msp; 82 uint64_t vca_outstanding_bytes; 83 kcondvar_t vca_cv; 84 kmutex_t vca_lock; 85 } vdev_copy_arg_t; 86 87 /* 88 * The maximum amount of memory we can use for outstanding i/o while 89 * doing a device removal. This determines how much i/o we can have 90 * in flight concurrently. 91 */ 92 int zfs_remove_max_copy_bytes = 64 * 1024 * 1024; 93 94 /* 95 * The largest contiguous segment that we will attempt to allocate when 96 * removing a device. This can be no larger than SPA_MAXBLOCKSIZE. If 97 * there is a performance problem with attempting to allocate large blocks, 98 * consider decreasing this. 99 * 100 * Note: we will issue I/Os of up to this size. The mpt driver does not 101 * respond well to I/Os larger than 1MB, so we set this to 1MB. (When 102 * mpt processes an I/O larger than 1MB, it needs to do an allocation of 103 * 2 physically contiguous pages; if this allocation fails, mpt will drop 104 * the I/O and hang the device.) 105 */ 106 int zfs_remove_max_segment = 1024 * 1024; 107 108 /* 109 * Allow a remap segment to span free chunks of at most this size. The main 110 * impact of a larger span is that we will read and write larger, more 111 * contiguous chunks, with more "unnecessary" data -- trading off bandwidth 112 * for iops. The value here was chosen to align with 113 * zfs_vdev_read_gap_limit, which is a similar concept when doing regular 114 * reads (but there's no reason it has to be the same). 115 * 116 * Additionally, a higher span will have the following relatively minor 117 * effects: 118 * - the mapping will be smaller, since one entry can cover more allocated 119 * segments 120 * - more of the fragmentation in the removing device will be preserved 121 * - we'll do larger allocations, which may fail and fall back on smaller 122 * allocations 123 */ 124 int vdev_removal_max_span = 32 * 1024; 125 126 /* 127 * This is used by the test suite so that it can ensure that certain 128 * actions happen while in the middle of a removal. 129 */ 130 int zfs_removal_suspend_progress = 0; 131 132 #define VDEV_REMOVAL_ZAP_OBJS "lzap" 133 134 static void spa_vdev_remove_thread(void *arg); 135 136 static void 137 spa_sync_removing_state(spa_t *spa, dmu_tx_t *tx) 138 { 139 VERIFY0(zap_update(spa->spa_dsl_pool->dp_meta_objset, 140 DMU_POOL_DIRECTORY_OBJECT, 141 DMU_POOL_REMOVING, sizeof (uint64_t), 142 sizeof (spa->spa_removing_phys) / sizeof (uint64_t), 143 &spa->spa_removing_phys, tx)); 144 } 145 146 static nvlist_t * 147 spa_nvlist_lookup_by_guid(nvlist_t **nvpp, int count, uint64_t target_guid) 148 { 149 for (int i = 0; i < count; i++) { 150 uint64_t guid = 151 fnvlist_lookup_uint64(nvpp[i], ZPOOL_CONFIG_GUID); 152 153 if (guid == target_guid) 154 return (nvpp[i]); 155 } 156 157 return (NULL); 158 } 159 160 static void 161 spa_vdev_remove_aux(nvlist_t *config, char *name, nvlist_t **dev, int count, 162 nvlist_t *dev_to_remove) 163 { 164 nvlist_t **newdev = NULL; 165 166 if (count > 1) 167 newdev = kmem_alloc((count - 1) * sizeof (void *), KM_SLEEP); 168 169 for (int i = 0, j = 0; i < count; i++) { 170 if (dev[i] == dev_to_remove) 171 continue; 172 VERIFY(nvlist_dup(dev[i], &newdev[j++], KM_SLEEP) == 0); 173 } 174 175 VERIFY(nvlist_remove(config, name, DATA_TYPE_NVLIST_ARRAY) == 0); 176 VERIFY(nvlist_add_nvlist_array(config, name, newdev, count - 1) == 0); 177 178 for (int i = 0; i < count - 1; i++) 179 nvlist_free(newdev[i]); 180 181 if (count > 1) 182 kmem_free(newdev, (count - 1) * sizeof (void *)); 183 } 184 185 static spa_vdev_removal_t * 186 spa_vdev_removal_create(vdev_t *vd) 187 { 188 spa_vdev_removal_t *svr = kmem_zalloc(sizeof (*svr), KM_SLEEP); 189 mutex_init(&svr->svr_lock, NULL, MUTEX_DEFAULT, NULL); 190 cv_init(&svr->svr_cv, NULL, CV_DEFAULT, NULL); 191 svr->svr_allocd_segs = range_tree_create(NULL, NULL); 192 svr->svr_vdev_id = vd->vdev_id; 193 194 for (int i = 0; i < TXG_SIZE; i++) { 195 svr->svr_frees[i] = range_tree_create(NULL, NULL); 196 list_create(&svr->svr_new_segments[i], 197 sizeof (vdev_indirect_mapping_entry_t), 198 offsetof(vdev_indirect_mapping_entry_t, vime_node)); 199 } 200 201 return (svr); 202 } 203 204 void 205 spa_vdev_removal_destroy(spa_vdev_removal_t *svr) 206 { 207 for (int i = 0; i < TXG_SIZE; i++) { 208 ASSERT0(svr->svr_bytes_done[i]); 209 ASSERT0(svr->svr_max_offset_to_sync[i]); 210 range_tree_destroy(svr->svr_frees[i]); 211 list_destroy(&svr->svr_new_segments[i]); 212 } 213 214 range_tree_destroy(svr->svr_allocd_segs); 215 mutex_destroy(&svr->svr_lock); 216 cv_destroy(&svr->svr_cv); 217 kmem_free(svr, sizeof (*svr)); 218 } 219 220 /* 221 * This is called as a synctask in the txg in which we will mark this vdev 222 * as removing (in the config stored in the MOS). 223 * 224 * It begins the evacuation of a toplevel vdev by: 225 * - initializing the spa_removing_phys which tracks this removal 226 * - computing the amount of space to remove for accounting purposes 227 * - dirtying all dbufs in the spa_config_object 228 * - creating the spa_vdev_removal 229 * - starting the spa_vdev_remove_thread 230 */ 231 static void 232 vdev_remove_initiate_sync(void *arg, dmu_tx_t *tx) 233 { 234 int vdev_id = (uintptr_t)arg; 235 spa_t *spa = dmu_tx_pool(tx)->dp_spa; 236 vdev_t *vd = vdev_lookup_top(spa, vdev_id); 237 vdev_indirect_config_t *vic = &vd->vdev_indirect_config; 238 objset_t *mos = spa->spa_dsl_pool->dp_meta_objset; 239 spa_vdev_removal_t *svr = NULL; 240 uint64_t txg = dmu_tx_get_txg(tx); 241 242 ASSERT3P(vd->vdev_ops, !=, &vdev_raidz_ops); 243 svr = spa_vdev_removal_create(vd); 244 245 ASSERT(vd->vdev_removing); 246 ASSERT3P(vd->vdev_indirect_mapping, ==, NULL); 247 248 spa_feature_incr(spa, SPA_FEATURE_DEVICE_REMOVAL, tx); 249 if (spa_feature_is_enabled(spa, SPA_FEATURE_OBSOLETE_COUNTS)) { 250 /* 251 * By activating the OBSOLETE_COUNTS feature, we prevent 252 * the pool from being downgraded and ensure that the 253 * refcounts are precise. 254 */ 255 spa_feature_incr(spa, SPA_FEATURE_OBSOLETE_COUNTS, tx); 256 uint64_t one = 1; 257 VERIFY0(zap_add(spa->spa_meta_objset, vd->vdev_top_zap, 258 VDEV_TOP_ZAP_OBSOLETE_COUNTS_ARE_PRECISE, sizeof (one), 1, 259 &one, tx)); 260 ASSERT3U(vdev_obsolete_counts_are_precise(vd), !=, 0); 261 } 262 263 vic->vic_mapping_object = vdev_indirect_mapping_alloc(mos, tx); 264 vd->vdev_indirect_mapping = 265 vdev_indirect_mapping_open(mos, vic->vic_mapping_object); 266 vic->vic_births_object = vdev_indirect_births_alloc(mos, tx); 267 vd->vdev_indirect_births = 268 vdev_indirect_births_open(mos, vic->vic_births_object); 269 spa->spa_removing_phys.sr_removing_vdev = vd->vdev_id; 270 spa->spa_removing_phys.sr_start_time = gethrestime_sec(); 271 spa->spa_removing_phys.sr_end_time = 0; 272 spa->spa_removing_phys.sr_state = DSS_SCANNING; 273 spa->spa_removing_phys.sr_to_copy = 0; 274 spa->spa_removing_phys.sr_copied = 0; 275 276 /* 277 * Note: We can't use vdev_stat's vs_alloc for sr_to_copy, because 278 * there may be space in the defer tree, which is free, but still 279 * counted in vs_alloc. 280 */ 281 for (uint64_t i = 0; i < vd->vdev_ms_count; i++) { 282 metaslab_t *ms = vd->vdev_ms[i]; 283 if (ms->ms_sm == NULL) 284 continue; 285 286 spa->spa_removing_phys.sr_to_copy += 287 metaslab_allocated_space(ms); 288 289 /* 290 * Space which we are freeing this txg does not need to 291 * be copied. 292 */ 293 spa->spa_removing_phys.sr_to_copy -= 294 range_tree_space(ms->ms_freeing); 295 296 ASSERT0(range_tree_space(ms->ms_freed)); 297 for (int t = 0; t < TXG_SIZE; t++) 298 ASSERT0(range_tree_space(ms->ms_allocating[t])); 299 } 300 301 /* 302 * Sync tasks are called before metaslab_sync(), so there should 303 * be no already-synced metaslabs in the TXG_CLEAN list. 304 */ 305 ASSERT3P(txg_list_head(&vd->vdev_ms_list, TXG_CLEAN(txg)), ==, NULL); 306 307 spa_sync_removing_state(spa, tx); 308 309 /* 310 * All blocks that we need to read the most recent mapping must be 311 * stored on concrete vdevs. Therefore, we must dirty anything that 312 * is read before spa_remove_init(). Specifically, the 313 * spa_config_object. (Note that although we already modified the 314 * spa_config_object in spa_sync_removing_state, that may not have 315 * modified all blocks of the object.) 316 */ 317 dmu_object_info_t doi; 318 VERIFY0(dmu_object_info(mos, DMU_POOL_DIRECTORY_OBJECT, &doi)); 319 for (uint64_t offset = 0; offset < doi.doi_max_offset; ) { 320 dmu_buf_t *dbuf; 321 VERIFY0(dmu_buf_hold(mos, DMU_POOL_DIRECTORY_OBJECT, 322 offset, FTAG, &dbuf, 0)); 323 dmu_buf_will_dirty(dbuf, tx); 324 offset += dbuf->db_size; 325 dmu_buf_rele(dbuf, FTAG); 326 } 327 328 /* 329 * Now that we've allocated the im_object, dirty the vdev to ensure 330 * that the object gets written to the config on disk. 331 */ 332 vdev_config_dirty(vd); 333 334 zfs_dbgmsg("starting removal thread for vdev %llu (%p) in txg %llu " 335 "im_obj=%llu", vd->vdev_id, vd, dmu_tx_get_txg(tx), 336 vic->vic_mapping_object); 337 338 spa_history_log_internal(spa, "vdev remove started", tx, 339 "%s vdev %llu %s", spa_name(spa), vd->vdev_id, 340 (vd->vdev_path != NULL) ? vd->vdev_path : "-"); 341 /* 342 * Setting spa_vdev_removal causes subsequent frees to call 343 * free_from_removing_vdev(). Note that we don't need any locking 344 * because we are the sync thread, and metaslab_free_impl() is only 345 * called from syncing context (potentially from a zio taskq thread, 346 * but in any case only when there are outstanding free i/os, which 347 * there are not). 348 */ 349 ASSERT3P(spa->spa_vdev_removal, ==, NULL); 350 spa->spa_vdev_removal = svr; 351 svr->svr_thread = thread_create(NULL, 0, 352 spa_vdev_remove_thread, spa, 0, &p0, TS_RUN, minclsyspri); 353 } 354 355 /* 356 * When we are opening a pool, we must read the mapping for each 357 * indirect vdev in order from most recently removed to least 358 * recently removed. We do this because the blocks for the mapping 359 * of older indirect vdevs may be stored on more recently removed vdevs. 360 * In order to read each indirect mapping object, we must have 361 * initialized all more recently removed vdevs. 362 */ 363 int 364 spa_remove_init(spa_t *spa) 365 { 366 int error; 367 368 error = zap_lookup(spa->spa_dsl_pool->dp_meta_objset, 369 DMU_POOL_DIRECTORY_OBJECT, 370 DMU_POOL_REMOVING, sizeof (uint64_t), 371 sizeof (spa->spa_removing_phys) / sizeof (uint64_t), 372 &spa->spa_removing_phys); 373 374 if (error == ENOENT) { 375 spa->spa_removing_phys.sr_state = DSS_NONE; 376 spa->spa_removing_phys.sr_removing_vdev = -1; 377 spa->spa_removing_phys.sr_prev_indirect_vdev = -1; 378 spa->spa_indirect_vdevs_loaded = B_TRUE; 379 return (0); 380 } else if (error != 0) { 381 return (error); 382 } 383 384 if (spa->spa_removing_phys.sr_state == DSS_SCANNING) { 385 /* 386 * We are currently removing a vdev. Create and 387 * initialize a spa_vdev_removal_t from the bonus 388 * buffer of the removing vdevs vdev_im_object, and 389 * initialize its partial mapping. 390 */ 391 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER); 392 vdev_t *vd = vdev_lookup_top(spa, 393 spa->spa_removing_phys.sr_removing_vdev); 394 395 if (vd == NULL) { 396 spa_config_exit(spa, SCL_STATE, FTAG); 397 return (EINVAL); 398 } 399 400 vdev_indirect_config_t *vic = &vd->vdev_indirect_config; 401 402 ASSERT(vdev_is_concrete(vd)); 403 spa_vdev_removal_t *svr = spa_vdev_removal_create(vd); 404 ASSERT3U(svr->svr_vdev_id, ==, vd->vdev_id); 405 ASSERT(vd->vdev_removing); 406 407 vd->vdev_indirect_mapping = vdev_indirect_mapping_open( 408 spa->spa_meta_objset, vic->vic_mapping_object); 409 vd->vdev_indirect_births = vdev_indirect_births_open( 410 spa->spa_meta_objset, vic->vic_births_object); 411 spa_config_exit(spa, SCL_STATE, FTAG); 412 413 spa->spa_vdev_removal = svr; 414 } 415 416 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER); 417 uint64_t indirect_vdev_id = 418 spa->spa_removing_phys.sr_prev_indirect_vdev; 419 while (indirect_vdev_id != UINT64_MAX) { 420 vdev_t *vd = vdev_lookup_top(spa, indirect_vdev_id); 421 vdev_indirect_config_t *vic = &vd->vdev_indirect_config; 422 423 ASSERT3P(vd->vdev_ops, ==, &vdev_indirect_ops); 424 vd->vdev_indirect_mapping = vdev_indirect_mapping_open( 425 spa->spa_meta_objset, vic->vic_mapping_object); 426 vd->vdev_indirect_births = vdev_indirect_births_open( 427 spa->spa_meta_objset, vic->vic_births_object); 428 429 indirect_vdev_id = vic->vic_prev_indirect_vdev; 430 } 431 spa_config_exit(spa, SCL_STATE, FTAG); 432 433 /* 434 * Now that we've loaded all the indirect mappings, we can allow 435 * reads from other blocks (e.g. via predictive prefetch). 436 */ 437 spa->spa_indirect_vdevs_loaded = B_TRUE; 438 return (0); 439 } 440 441 void 442 spa_restart_removal(spa_t *spa) 443 { 444 spa_vdev_removal_t *svr = spa->spa_vdev_removal; 445 446 if (svr == NULL) 447 return; 448 449 /* 450 * In general when this function is called there is no 451 * removal thread running. The only scenario where this 452 * is not true is during spa_import() where this function 453 * is called twice [once from spa_import_impl() and 454 * spa_async_resume()]. Thus, in the scenario where we 455 * import a pool that has an ongoing removal we don't 456 * want to spawn a second thread. 457 */ 458 if (svr->svr_thread != NULL) 459 return; 460 461 if (!spa_writeable(spa)) 462 return; 463 464 zfs_dbgmsg("restarting removal of %llu", svr->svr_vdev_id); 465 svr->svr_thread = thread_create(NULL, 0, spa_vdev_remove_thread, spa, 466 0, &p0, TS_RUN, minclsyspri); 467 } 468 469 /* 470 * Process freeing from a device which is in the middle of being removed. 471 * We must handle this carefully so that we attempt to copy freed data, 472 * and we correctly free already-copied data. 473 */ 474 void 475 free_from_removing_vdev(vdev_t *vd, uint64_t offset, uint64_t size) 476 { 477 spa_t *spa = vd->vdev_spa; 478 spa_vdev_removal_t *svr = spa->spa_vdev_removal; 479 vdev_indirect_mapping_t *vim = vd->vdev_indirect_mapping; 480 uint64_t txg = spa_syncing_txg(spa); 481 uint64_t max_offset_yet = 0; 482 483 ASSERT(vd->vdev_indirect_config.vic_mapping_object != 0); 484 ASSERT3U(vd->vdev_indirect_config.vic_mapping_object, ==, 485 vdev_indirect_mapping_object(vim)); 486 ASSERT3U(vd->vdev_id, ==, svr->svr_vdev_id); 487 488 mutex_enter(&svr->svr_lock); 489 490 /* 491 * Remove the segment from the removing vdev's spacemap. This 492 * ensures that we will not attempt to copy this space (if the 493 * removal thread has not yet visited it), and also ensures 494 * that we know what is actually allocated on the new vdevs 495 * (needed if we cancel the removal). 496 * 497 * Note: we must do the metaslab_free_concrete() with the svr_lock 498 * held, so that the remove_thread can not load this metaslab and then 499 * visit this offset between the time that we metaslab_free_concrete() 500 * and when we check to see if it has been visited. 501 * 502 * Note: The checkpoint flag is set to false as having/taking 503 * a checkpoint and removing a device can't happen at the same 504 * time. 505 */ 506 ASSERT(!spa_has_checkpoint(spa)); 507 metaslab_free_concrete(vd, offset, size, B_FALSE); 508 509 uint64_t synced_size = 0; 510 uint64_t synced_offset = 0; 511 uint64_t max_offset_synced = vdev_indirect_mapping_max_offset(vim); 512 if (offset < max_offset_synced) { 513 /* 514 * The mapping for this offset is already on disk. 515 * Free from the new location. 516 * 517 * Note that we use svr_max_synced_offset because it is 518 * updated atomically with respect to the in-core mapping. 519 * By contrast, vim_max_offset is not. 520 * 521 * This block may be split between a synced entry and an 522 * in-flight or unvisited entry. Only process the synced 523 * portion of it here. 524 */ 525 synced_size = MIN(size, max_offset_synced - offset); 526 synced_offset = offset; 527 528 ASSERT3U(max_offset_yet, <=, max_offset_synced); 529 max_offset_yet = max_offset_synced; 530 531 DTRACE_PROBE3(remove__free__synced, 532 spa_t *, spa, 533 uint64_t, offset, 534 uint64_t, synced_size); 535 536 size -= synced_size; 537 offset += synced_size; 538 } 539 540 /* 541 * Look at all in-flight txgs starting from the currently syncing one 542 * and see if a section of this free is being copied. By starting from 543 * this txg and iterating forward, we might find that this region 544 * was copied in two different txgs and handle it appropriately. 545 */ 546 for (int i = 0; i < TXG_CONCURRENT_STATES; i++) { 547 int txgoff = (txg + i) & TXG_MASK; 548 if (size > 0 && offset < svr->svr_max_offset_to_sync[txgoff]) { 549 /* 550 * The mapping for this offset is in flight, and 551 * will be synced in txg+i. 552 */ 553 uint64_t inflight_size = MIN(size, 554 svr->svr_max_offset_to_sync[txgoff] - offset); 555 556 DTRACE_PROBE4(remove__free__inflight, 557 spa_t *, spa, 558 uint64_t, offset, 559 uint64_t, inflight_size, 560 uint64_t, txg + i); 561 562 /* 563 * We copy data in order of increasing offset. 564 * Therefore the max_offset_to_sync[] must increase 565 * (or be zero, indicating that nothing is being 566 * copied in that txg). 567 */ 568 if (svr->svr_max_offset_to_sync[txgoff] != 0) { 569 ASSERT3U(svr->svr_max_offset_to_sync[txgoff], 570 >=, max_offset_yet); 571 max_offset_yet = 572 svr->svr_max_offset_to_sync[txgoff]; 573 } 574 575 /* 576 * We've already committed to copying this segment: 577 * we have allocated space elsewhere in the pool for 578 * it and have an IO outstanding to copy the data. We 579 * cannot free the space before the copy has 580 * completed, or else the copy IO might overwrite any 581 * new data. To free that space, we record the 582 * segment in the appropriate svr_frees tree and free 583 * the mapped space later, in the txg where we have 584 * completed the copy and synced the mapping (see 585 * vdev_mapping_sync). 586 */ 587 range_tree_add(svr->svr_frees[txgoff], 588 offset, inflight_size); 589 size -= inflight_size; 590 offset += inflight_size; 591 592 /* 593 * This space is already accounted for as being 594 * done, because it is being copied in txg+i. 595 * However, if i!=0, then it is being copied in 596 * a future txg. If we crash after this txg 597 * syncs but before txg+i syncs, then the space 598 * will be free. Therefore we must account 599 * for the space being done in *this* txg 600 * (when it is freed) rather than the future txg 601 * (when it will be copied). 602 */ 603 ASSERT3U(svr->svr_bytes_done[txgoff], >=, 604 inflight_size); 605 svr->svr_bytes_done[txgoff] -= inflight_size; 606 svr->svr_bytes_done[txg & TXG_MASK] += inflight_size; 607 } 608 } 609 ASSERT0(svr->svr_max_offset_to_sync[TXG_CLEAN(txg) & TXG_MASK]); 610 611 if (size > 0) { 612 /* 613 * The copy thread has not yet visited this offset. Ensure 614 * that it doesn't. 615 */ 616 617 DTRACE_PROBE3(remove__free__unvisited, 618 spa_t *, spa, 619 uint64_t, offset, 620 uint64_t, size); 621 622 if (svr->svr_allocd_segs != NULL) 623 range_tree_clear(svr->svr_allocd_segs, offset, size); 624 625 /* 626 * Since we now do not need to copy this data, for 627 * accounting purposes we have done our job and can count 628 * it as completed. 629 */ 630 svr->svr_bytes_done[txg & TXG_MASK] += size; 631 } 632 mutex_exit(&svr->svr_lock); 633 634 /* 635 * Now that we have dropped svr_lock, process the synced portion 636 * of this free. 637 */ 638 if (synced_size > 0) { 639 vdev_indirect_mark_obsolete(vd, synced_offset, synced_size); 640 641 /* 642 * Note: this can only be called from syncing context, 643 * and the vdev_indirect_mapping is only changed from the 644 * sync thread, so we don't need svr_lock while doing 645 * metaslab_free_impl_cb. 646 */ 647 boolean_t checkpoint = B_FALSE; 648 vdev_indirect_ops.vdev_op_remap(vd, synced_offset, synced_size, 649 metaslab_free_impl_cb, &checkpoint); 650 } 651 } 652 653 /* 654 * Stop an active removal and update the spa_removing phys. 655 */ 656 static void 657 spa_finish_removal(spa_t *spa, dsl_scan_state_t state, dmu_tx_t *tx) 658 { 659 spa_vdev_removal_t *svr = spa->spa_vdev_removal; 660 ASSERT3U(dmu_tx_get_txg(tx), ==, spa_syncing_txg(spa)); 661 662 /* Ensure the removal thread has completed before we free the svr. */ 663 spa_vdev_remove_suspend(spa); 664 665 ASSERT(state == DSS_FINISHED || state == DSS_CANCELED); 666 667 if (state == DSS_FINISHED) { 668 spa_removing_phys_t *srp = &spa->spa_removing_phys; 669 vdev_t *vd = vdev_lookup_top(spa, svr->svr_vdev_id); 670 vdev_indirect_config_t *vic = &vd->vdev_indirect_config; 671 672 if (srp->sr_prev_indirect_vdev != UINT64_MAX) { 673 vdev_t *pvd = vdev_lookup_top(spa, 674 srp->sr_prev_indirect_vdev); 675 ASSERT3P(pvd->vdev_ops, ==, &vdev_indirect_ops); 676 } 677 678 vic->vic_prev_indirect_vdev = srp->sr_prev_indirect_vdev; 679 srp->sr_prev_indirect_vdev = vd->vdev_id; 680 } 681 spa->spa_removing_phys.sr_state = state; 682 spa->spa_removing_phys.sr_end_time = gethrestime_sec(); 683 684 spa->spa_vdev_removal = NULL; 685 spa_vdev_removal_destroy(svr); 686 687 spa_sync_removing_state(spa, tx); 688 689 vdev_config_dirty(spa->spa_root_vdev); 690 } 691 692 static void 693 free_mapped_segment_cb(void *arg, uint64_t offset, uint64_t size) 694 { 695 vdev_t *vd = arg; 696 vdev_indirect_mark_obsolete(vd, offset, size); 697 boolean_t checkpoint = B_FALSE; 698 vdev_indirect_ops.vdev_op_remap(vd, offset, size, 699 metaslab_free_impl_cb, &checkpoint); 700 } 701 702 /* 703 * On behalf of the removal thread, syncs an incremental bit more of 704 * the indirect mapping to disk and updates the in-memory mapping. 705 * Called as a sync task in every txg that the removal thread makes progress. 706 */ 707 static void 708 vdev_mapping_sync(void *arg, dmu_tx_t *tx) 709 { 710 spa_vdev_removal_t *svr = arg; 711 spa_t *spa = dmu_tx_pool(tx)->dp_spa; 712 vdev_t *vd = vdev_lookup_top(spa, svr->svr_vdev_id); 713 vdev_indirect_config_t *vic = &vd->vdev_indirect_config; 714 uint64_t txg = dmu_tx_get_txg(tx); 715 vdev_indirect_mapping_t *vim = vd->vdev_indirect_mapping; 716 717 ASSERT(vic->vic_mapping_object != 0); 718 ASSERT3U(txg, ==, spa_syncing_txg(spa)); 719 720 vdev_indirect_mapping_add_entries(vim, 721 &svr->svr_new_segments[txg & TXG_MASK], tx); 722 vdev_indirect_births_add_entry(vd->vdev_indirect_births, 723 vdev_indirect_mapping_max_offset(vim), dmu_tx_get_txg(tx), tx); 724 725 /* 726 * Free the copied data for anything that was freed while the 727 * mapping entries were in flight. 728 */ 729 mutex_enter(&svr->svr_lock); 730 range_tree_vacate(svr->svr_frees[txg & TXG_MASK], 731 free_mapped_segment_cb, vd); 732 ASSERT3U(svr->svr_max_offset_to_sync[txg & TXG_MASK], >=, 733 vdev_indirect_mapping_max_offset(vim)); 734 svr->svr_max_offset_to_sync[txg & TXG_MASK] = 0; 735 mutex_exit(&svr->svr_lock); 736 737 spa_sync_removing_state(spa, tx); 738 } 739 740 typedef struct vdev_copy_segment_arg { 741 spa_t *vcsa_spa; 742 dva_t *vcsa_dest_dva; 743 uint64_t vcsa_txg; 744 range_tree_t *vcsa_obsolete_segs; 745 } vdev_copy_segment_arg_t; 746 747 static void 748 unalloc_seg(void *arg, uint64_t start, uint64_t size) 749 { 750 vdev_copy_segment_arg_t *vcsa = arg; 751 spa_t *spa = vcsa->vcsa_spa; 752 blkptr_t bp = { 0 }; 753 754 BP_SET_BIRTH(&bp, TXG_INITIAL, TXG_INITIAL); 755 BP_SET_LSIZE(&bp, size); 756 BP_SET_PSIZE(&bp, size); 757 BP_SET_COMPRESS(&bp, ZIO_COMPRESS_OFF); 758 BP_SET_CHECKSUM(&bp, ZIO_CHECKSUM_OFF); 759 BP_SET_TYPE(&bp, DMU_OT_NONE); 760 BP_SET_LEVEL(&bp, 0); 761 BP_SET_DEDUP(&bp, 0); 762 BP_SET_BYTEORDER(&bp, ZFS_HOST_BYTEORDER); 763 764 DVA_SET_VDEV(&bp.blk_dva[0], DVA_GET_VDEV(vcsa->vcsa_dest_dva)); 765 DVA_SET_OFFSET(&bp.blk_dva[0], 766 DVA_GET_OFFSET(vcsa->vcsa_dest_dva) + start); 767 DVA_SET_ASIZE(&bp.blk_dva[0], size); 768 769 zio_free(spa, vcsa->vcsa_txg, &bp); 770 } 771 772 /* 773 * All reads and writes associated with a call to spa_vdev_copy_segment() 774 * are done. 775 */ 776 static void 777 spa_vdev_copy_segment_done(zio_t *zio) 778 { 779 vdev_copy_segment_arg_t *vcsa = zio->io_private; 780 781 range_tree_vacate(vcsa->vcsa_obsolete_segs, 782 unalloc_seg, vcsa); 783 range_tree_destroy(vcsa->vcsa_obsolete_segs); 784 kmem_free(vcsa, sizeof (*vcsa)); 785 786 spa_config_exit(zio->io_spa, SCL_STATE, zio->io_spa); 787 } 788 789 /* 790 * The write of the new location is done. 791 */ 792 static void 793 spa_vdev_copy_segment_write_done(zio_t *zio) 794 { 795 vdev_copy_arg_t *vca = zio->io_private; 796 797 abd_free(zio->io_abd); 798 799 mutex_enter(&vca->vca_lock); 800 vca->vca_outstanding_bytes -= zio->io_size; 801 cv_signal(&vca->vca_cv); 802 mutex_exit(&vca->vca_lock); 803 } 804 805 /* 806 * The read of the old location is done. The parent zio is the write to 807 * the new location. Allow it to start. 808 */ 809 static void 810 spa_vdev_copy_segment_read_done(zio_t *zio) 811 { 812 zio_nowait(zio_unique_parent(zio)); 813 } 814 815 /* 816 * If the old and new vdevs are mirrors, we will read both sides of the old 817 * mirror, and write each copy to the corresponding side of the new mirror. 818 * If the old and new vdevs have a different number of children, we will do 819 * this as best as possible. Since we aren't verifying checksums, this 820 * ensures that as long as there's a good copy of the data, we'll have a 821 * good copy after the removal, even if there's silent damage to one side 822 * of the mirror. If we're removing a mirror that has some silent damage, 823 * we'll have exactly the same damage in the new location (assuming that 824 * the new location is also a mirror). 825 * 826 * We accomplish this by creating a tree of zio_t's, with as many writes as 827 * there are "children" of the new vdev (a non-redundant vdev counts as one 828 * child, a 2-way mirror has 2 children, etc). Each write has an associated 829 * read from a child of the old vdev. Typically there will be the same 830 * number of children of the old and new vdevs. However, if there are more 831 * children of the new vdev, some child(ren) of the old vdev will be issued 832 * multiple reads. If there are more children of the old vdev, some copies 833 * will be dropped. 834 * 835 * For example, the tree of zio_t's for a 2-way mirror is: 836 * 837 * null 838 * / \ 839 * write(new vdev, child 0) write(new vdev, child 1) 840 * | | 841 * read(old vdev, child 0) read(old vdev, child 1) 842 * 843 * Child zio's complete before their parents complete. However, zio's 844 * created with zio_vdev_child_io() may be issued before their children 845 * complete. In this case we need to make sure that the children (reads) 846 * complete before the parents (writes) are *issued*. We do this by not 847 * calling zio_nowait() on each write until its corresponding read has 848 * completed. 849 * 850 * The spa_config_lock must be held while zio's created by 851 * zio_vdev_child_io() are in progress, to ensure that the vdev tree does 852 * not change (e.g. due to a concurrent "zpool attach/detach"). The "null" 853 * zio is needed to release the spa_config_lock after all the reads and 854 * writes complete. (Note that we can't grab the config lock for each read, 855 * because it is not reentrant - we could deadlock with a thread waiting 856 * for a write lock.) 857 */ 858 static void 859 spa_vdev_copy_one_child(vdev_copy_arg_t *vca, zio_t *nzio, 860 vdev_t *source_vd, uint64_t source_offset, 861 vdev_t *dest_child_vd, uint64_t dest_offset, int dest_id, uint64_t size) 862 { 863 ASSERT3U(spa_config_held(nzio->io_spa, SCL_ALL, RW_READER), !=, 0); 864 865 mutex_enter(&vca->vca_lock); 866 vca->vca_outstanding_bytes += size; 867 mutex_exit(&vca->vca_lock); 868 869 abd_t *abd = abd_alloc_for_io(size, B_FALSE); 870 871 vdev_t *source_child_vd; 872 if (source_vd->vdev_ops == &vdev_mirror_ops && dest_id != -1) { 873 /* 874 * Source and dest are both mirrors. Copy from the same 875 * child id as we are copying to (wrapping around if there 876 * are more dest children than source children). 877 */ 878 source_child_vd = 879 source_vd->vdev_child[dest_id % source_vd->vdev_children]; 880 } else { 881 source_child_vd = source_vd; 882 } 883 884 zio_t *write_zio = zio_vdev_child_io(nzio, NULL, 885 dest_child_vd, dest_offset, abd, size, 886 ZIO_TYPE_WRITE, ZIO_PRIORITY_REMOVAL, 887 ZIO_FLAG_CANFAIL, 888 spa_vdev_copy_segment_write_done, vca); 889 890 zio_nowait(zio_vdev_child_io(write_zio, NULL, 891 source_child_vd, source_offset, abd, size, 892 ZIO_TYPE_READ, ZIO_PRIORITY_REMOVAL, 893 ZIO_FLAG_CANFAIL, 894 spa_vdev_copy_segment_read_done, vca)); 895 } 896 897 /* 898 * Allocate a new location for this segment, and create the zio_t's to 899 * read from the old location and write to the new location. 900 */ 901 static int 902 spa_vdev_copy_segment(vdev_t *vd, range_tree_t *segs, 903 uint64_t maxalloc, uint64_t txg, 904 vdev_copy_arg_t *vca, zio_alloc_list_t *zal) 905 { 906 metaslab_group_t *mg = vd->vdev_mg; 907 spa_t *spa = vd->vdev_spa; 908 spa_vdev_removal_t *svr = spa->spa_vdev_removal; 909 vdev_indirect_mapping_entry_t *entry; 910 dva_t dst = { 0 }; 911 uint64_t start = range_tree_min(segs); 912 913 ASSERT3U(maxalloc, <=, SPA_MAXBLOCKSIZE); 914 915 uint64_t size = range_tree_span(segs); 916 if (range_tree_span(segs) > maxalloc) { 917 /* 918 * We can't allocate all the segments. Prefer to end 919 * the allocation at the end of a segment, thus avoiding 920 * additional split blocks. 921 */ 922 range_seg_t search; 923 avl_index_t where; 924 search.rs_start = start + maxalloc; 925 search.rs_end = search.rs_start; 926 range_seg_t *rs = avl_find(&segs->rt_root, &search, &where); 927 if (rs == NULL) { 928 rs = avl_nearest(&segs->rt_root, where, AVL_BEFORE); 929 } else { 930 rs = AVL_PREV(&segs->rt_root, rs); 931 } 932 if (rs != NULL) { 933 size = rs->rs_end - start; 934 } else { 935 /* 936 * There are no segments that end before maxalloc. 937 * I.e. the first segment is larger than maxalloc, 938 * so we must split it. 939 */ 940 size = maxalloc; 941 } 942 } 943 ASSERT3U(size, <=, maxalloc); 944 945 /* 946 * An allocation class might not have any remaining vdevs or space 947 */ 948 metaslab_class_t *mc = mg->mg_class; 949 if (mc != spa_normal_class(spa) && mc->mc_groups <= 1) 950 mc = spa_normal_class(spa); 951 int error = metaslab_alloc_dva(spa, mc, size, &dst, 0, NULL, txg, 0, 952 zal, 0); 953 if (error == ENOSPC && mc != spa_normal_class(spa)) { 954 error = metaslab_alloc_dva(spa, spa_normal_class(spa), size, 955 &dst, 0, NULL, txg, 0, zal, 0); 956 } 957 if (error != 0) 958 return (error); 959 960 /* 961 * Determine the ranges that are not actually needed. Offsets are 962 * relative to the start of the range to be copied (i.e. relative to the 963 * local variable "start"). 964 */ 965 range_tree_t *obsolete_segs = range_tree_create(NULL, NULL); 966 967 range_seg_t *rs = avl_first(&segs->rt_root); 968 ASSERT3U(rs->rs_start, ==, start); 969 uint64_t prev_seg_end = rs->rs_end; 970 while ((rs = AVL_NEXT(&segs->rt_root, rs)) != NULL) { 971 if (rs->rs_start >= start + size) { 972 break; 973 } else { 974 range_tree_add(obsolete_segs, 975 prev_seg_end - start, 976 rs->rs_start - prev_seg_end); 977 } 978 prev_seg_end = rs->rs_end; 979 } 980 /* We don't end in the middle of an obsolete range */ 981 ASSERT3U(start + size, <=, prev_seg_end); 982 983 range_tree_clear(segs, start, size); 984 985 /* 986 * We can't have any padding of the allocated size, otherwise we will 987 * misunderstand what's allocated, and the size of the mapping. 988 * The caller ensures this will be true by passing in a size that is 989 * aligned to the worst (highest) ashift in the pool. 990 */ 991 ASSERT3U(DVA_GET_ASIZE(&dst), ==, size); 992 993 entry = kmem_zalloc(sizeof (vdev_indirect_mapping_entry_t), KM_SLEEP); 994 DVA_MAPPING_SET_SRC_OFFSET(&entry->vime_mapping, start); 995 entry->vime_mapping.vimep_dst = dst; 996 if (spa_feature_is_enabled(spa, SPA_FEATURE_OBSOLETE_COUNTS)) { 997 entry->vime_obsolete_count = range_tree_space(obsolete_segs); 998 } 999 1000 vdev_copy_segment_arg_t *vcsa = kmem_zalloc(sizeof (*vcsa), KM_SLEEP); 1001 vcsa->vcsa_dest_dva = &entry->vime_mapping.vimep_dst; 1002 vcsa->vcsa_obsolete_segs = obsolete_segs; 1003 vcsa->vcsa_spa = spa; 1004 vcsa->vcsa_txg = txg; 1005 1006 /* 1007 * See comment before spa_vdev_copy_one_child(). 1008 */ 1009 spa_config_enter(spa, SCL_STATE, spa, RW_READER); 1010 zio_t *nzio = zio_null(spa->spa_txg_zio[txg & TXG_MASK], spa, NULL, 1011 spa_vdev_copy_segment_done, vcsa, 0); 1012 vdev_t *dest_vd = vdev_lookup_top(spa, DVA_GET_VDEV(&dst)); 1013 if (dest_vd->vdev_ops == &vdev_mirror_ops) { 1014 for (int i = 0; i < dest_vd->vdev_children; i++) { 1015 vdev_t *child = dest_vd->vdev_child[i]; 1016 spa_vdev_copy_one_child(vca, nzio, vd, start, 1017 child, DVA_GET_OFFSET(&dst), i, size); 1018 } 1019 } else { 1020 spa_vdev_copy_one_child(vca, nzio, vd, start, 1021 dest_vd, DVA_GET_OFFSET(&dst), -1, size); 1022 } 1023 zio_nowait(nzio); 1024 1025 list_insert_tail(&svr->svr_new_segments[txg & TXG_MASK], entry); 1026 ASSERT3U(start + size, <=, vd->vdev_ms_count << vd->vdev_ms_shift); 1027 vdev_dirty(vd, 0, NULL, txg); 1028 1029 return (0); 1030 } 1031 1032 /* 1033 * Complete the removal of a toplevel vdev. This is called as a 1034 * synctask in the same txg that we will sync out the new config (to the 1035 * MOS object) which indicates that this vdev is indirect. 1036 */ 1037 static void 1038 vdev_remove_complete_sync(void *arg, dmu_tx_t *tx) 1039 { 1040 spa_vdev_removal_t *svr = arg; 1041 spa_t *spa = dmu_tx_pool(tx)->dp_spa; 1042 vdev_t *vd = vdev_lookup_top(spa, svr->svr_vdev_id); 1043 1044 ASSERT3P(vd->vdev_ops, ==, &vdev_indirect_ops); 1045 1046 for (int i = 0; i < TXG_SIZE; i++) { 1047 ASSERT0(svr->svr_bytes_done[i]); 1048 } 1049 1050 ASSERT3U(spa->spa_removing_phys.sr_copied, ==, 1051 spa->spa_removing_phys.sr_to_copy); 1052 1053 vdev_destroy_spacemaps(vd, tx); 1054 1055 /* destroy leaf zaps, if any */ 1056 ASSERT3P(svr->svr_zaplist, !=, NULL); 1057 for (nvpair_t *pair = nvlist_next_nvpair(svr->svr_zaplist, NULL); 1058 pair != NULL; 1059 pair = nvlist_next_nvpair(svr->svr_zaplist, pair)) { 1060 vdev_destroy_unlink_zap(vd, fnvpair_value_uint64(pair), tx); 1061 } 1062 fnvlist_free(svr->svr_zaplist); 1063 1064 spa_finish_removal(dmu_tx_pool(tx)->dp_spa, DSS_FINISHED, tx); 1065 /* vd->vdev_path is not available here */ 1066 spa_history_log_internal(spa, "vdev remove completed", tx, 1067 "%s vdev %llu", spa_name(spa), vd->vdev_id); 1068 } 1069 1070 static void 1071 vdev_remove_enlist_zaps(vdev_t *vd, nvlist_t *zlist) 1072 { 1073 ASSERT3P(zlist, !=, NULL); 1074 ASSERT3P(vd->vdev_ops, !=, &vdev_raidz_ops); 1075 1076 if (vd->vdev_leaf_zap != 0) { 1077 char zkey[32]; 1078 (void) snprintf(zkey, sizeof (zkey), "%s-%"PRIu64, 1079 VDEV_REMOVAL_ZAP_OBJS, vd->vdev_leaf_zap); 1080 fnvlist_add_uint64(zlist, zkey, vd->vdev_leaf_zap); 1081 } 1082 1083 for (uint64_t id = 0; id < vd->vdev_children; id++) { 1084 vdev_remove_enlist_zaps(vd->vdev_child[id], zlist); 1085 } 1086 } 1087 1088 static void 1089 vdev_remove_replace_with_indirect(vdev_t *vd, uint64_t txg) 1090 { 1091 vdev_t *ivd; 1092 dmu_tx_t *tx; 1093 spa_t *spa = vd->vdev_spa; 1094 spa_vdev_removal_t *svr = spa->spa_vdev_removal; 1095 1096 /* 1097 * First, build a list of leaf zaps to be destroyed. 1098 * This is passed to the sync context thread, 1099 * which does the actual unlinking. 1100 */ 1101 svr->svr_zaplist = fnvlist_alloc(); 1102 vdev_remove_enlist_zaps(vd, svr->svr_zaplist); 1103 1104 ivd = vdev_add_parent(vd, &vdev_indirect_ops); 1105 ivd->vdev_removing = 0; 1106 1107 vd->vdev_leaf_zap = 0; 1108 1109 vdev_remove_child(ivd, vd); 1110 vdev_compact_children(ivd); 1111 1112 ASSERT(!list_link_active(&vd->vdev_state_dirty_node)); 1113 1114 tx = dmu_tx_create_assigned(spa->spa_dsl_pool, txg); 1115 dsl_sync_task_nowait(spa->spa_dsl_pool, vdev_remove_complete_sync, svr, 1116 0, ZFS_SPACE_CHECK_NONE, tx); 1117 dmu_tx_commit(tx); 1118 1119 /* 1120 * Indicate that this thread has exited. 1121 * After this, we can not use svr. 1122 */ 1123 mutex_enter(&svr->svr_lock); 1124 svr->svr_thread = NULL; 1125 cv_broadcast(&svr->svr_cv); 1126 mutex_exit(&svr->svr_lock); 1127 } 1128 1129 /* 1130 * Complete the removal of a toplevel vdev. This is called in open 1131 * context by the removal thread after we have copied all vdev's data. 1132 */ 1133 static void 1134 vdev_remove_complete(spa_t *spa) 1135 { 1136 uint64_t txg; 1137 1138 /* 1139 * Wait for any deferred frees to be synced before we call 1140 * vdev_metaslab_fini() 1141 */ 1142 txg_wait_synced(spa->spa_dsl_pool, 0); 1143 txg = spa_vdev_enter(spa); 1144 vdev_t *vd = vdev_lookup_top(spa, spa->spa_vdev_removal->svr_vdev_id); 1145 ASSERT3P(vd->vdev_initialize_thread, ==, NULL); 1146 1147 sysevent_t *ev = spa_event_create(spa, vd, NULL, 1148 ESC_ZFS_VDEV_REMOVE_DEV); 1149 1150 zfs_dbgmsg("finishing device removal for vdev %llu in txg %llu", 1151 vd->vdev_id, txg); 1152 1153 /* 1154 * Discard allocation state. 1155 */ 1156 if (vd->vdev_mg != NULL) { 1157 vdev_metaslab_fini(vd); 1158 metaslab_group_destroy(vd->vdev_mg); 1159 vd->vdev_mg = NULL; 1160 } 1161 ASSERT0(vd->vdev_stat.vs_space); 1162 ASSERT0(vd->vdev_stat.vs_dspace); 1163 1164 vdev_remove_replace_with_indirect(vd, txg); 1165 1166 /* 1167 * We now release the locks, allowing spa_sync to run and finish the 1168 * removal via vdev_remove_complete_sync in syncing context. 1169 * 1170 * Note that we hold on to the vdev_t that has been replaced. Since 1171 * it isn't part of the vdev tree any longer, it can't be concurrently 1172 * manipulated, even while we don't have the config lock. 1173 */ 1174 (void) spa_vdev_exit(spa, NULL, txg, 0); 1175 1176 /* 1177 * Top ZAP should have been transferred to the indirect vdev in 1178 * vdev_remove_replace_with_indirect. 1179 */ 1180 ASSERT0(vd->vdev_top_zap); 1181 1182 /* 1183 * Leaf ZAP should have been moved in vdev_remove_replace_with_indirect. 1184 */ 1185 ASSERT0(vd->vdev_leaf_zap); 1186 1187 txg = spa_vdev_enter(spa); 1188 (void) vdev_label_init(vd, 0, VDEV_LABEL_REMOVE); 1189 /* 1190 * Request to update the config and the config cachefile. 1191 */ 1192 vdev_config_dirty(spa->spa_root_vdev); 1193 (void) spa_vdev_exit(spa, vd, txg, 0); 1194 1195 spa_event_post(ev); 1196 } 1197 1198 /* 1199 * Evacuates a segment of size at most max_alloc from the vdev 1200 * via repeated calls to spa_vdev_copy_segment. If an allocation 1201 * fails, the pool is probably too fragmented to handle such a 1202 * large size, so decrease max_alloc so that the caller will not try 1203 * this size again this txg. 1204 */ 1205 static void 1206 spa_vdev_copy_impl(vdev_t *vd, spa_vdev_removal_t *svr, vdev_copy_arg_t *vca, 1207 uint64_t *max_alloc, dmu_tx_t *tx) 1208 { 1209 uint64_t txg = dmu_tx_get_txg(tx); 1210 spa_t *spa = dmu_tx_pool(tx)->dp_spa; 1211 1212 mutex_enter(&svr->svr_lock); 1213 1214 /* 1215 * Determine how big of a chunk to copy. We can allocate up 1216 * to max_alloc bytes, and we can span up to vdev_removal_max_span 1217 * bytes of unallocated space at a time. "segs" will track the 1218 * allocated segments that we are copying. We may also be copying 1219 * free segments (of up to vdev_removal_max_span bytes). 1220 */ 1221 range_tree_t *segs = range_tree_create(NULL, NULL); 1222 for (;;) { 1223 range_seg_t *rs = avl_first(&svr->svr_allocd_segs->rt_root); 1224 if (rs == NULL) 1225 break; 1226 1227 uint64_t seg_length; 1228 1229 if (range_tree_is_empty(segs)) { 1230 /* need to truncate the first seg based on max_alloc */ 1231 seg_length = 1232 MIN(rs->rs_end - rs->rs_start, *max_alloc); 1233 } else { 1234 if (rs->rs_start - range_tree_max(segs) > 1235 vdev_removal_max_span) { 1236 /* 1237 * Including this segment would cause us to 1238 * copy a larger unneeded chunk than is allowed. 1239 */ 1240 break; 1241 } else if (rs->rs_end - range_tree_min(segs) > 1242 *max_alloc) { 1243 /* 1244 * This additional segment would extend past 1245 * max_alloc. Rather than splitting this 1246 * segment, leave it for the next mapping. 1247 */ 1248 break; 1249 } else { 1250 seg_length = rs->rs_end - rs->rs_start; 1251 } 1252 } 1253 1254 range_tree_add(segs, rs->rs_start, seg_length); 1255 range_tree_remove(svr->svr_allocd_segs, 1256 rs->rs_start, seg_length); 1257 } 1258 1259 if (range_tree_is_empty(segs)) { 1260 mutex_exit(&svr->svr_lock); 1261 range_tree_destroy(segs); 1262 return; 1263 } 1264 1265 if (svr->svr_max_offset_to_sync[txg & TXG_MASK] == 0) { 1266 dsl_sync_task_nowait(dmu_tx_pool(tx), vdev_mapping_sync, 1267 svr, 0, ZFS_SPACE_CHECK_NONE, tx); 1268 } 1269 1270 svr->svr_max_offset_to_sync[txg & TXG_MASK] = range_tree_max(segs); 1271 1272 /* 1273 * Note: this is the amount of *allocated* space 1274 * that we are taking care of each txg. 1275 */ 1276 svr->svr_bytes_done[txg & TXG_MASK] += range_tree_space(segs); 1277 1278 mutex_exit(&svr->svr_lock); 1279 1280 zio_alloc_list_t zal; 1281 metaslab_trace_init(&zal); 1282 uint64_t thismax = SPA_MAXBLOCKSIZE; 1283 while (!range_tree_is_empty(segs)) { 1284 int error = spa_vdev_copy_segment(vd, 1285 segs, thismax, txg, vca, &zal); 1286 1287 if (error == ENOSPC) { 1288 /* 1289 * Cut our segment in half, and don't try this 1290 * segment size again this txg. Note that the 1291 * allocation size must be aligned to the highest 1292 * ashift in the pool, so that the allocation will 1293 * not be padded out to a multiple of the ashift, 1294 * which could cause us to think that this mapping 1295 * is larger than we intended. 1296 */ 1297 ASSERT3U(spa->spa_max_ashift, >=, SPA_MINBLOCKSHIFT); 1298 ASSERT3U(spa->spa_max_ashift, ==, spa->spa_min_ashift); 1299 uint64_t attempted = 1300 MIN(range_tree_span(segs), thismax); 1301 thismax = P2ROUNDUP(attempted / 2, 1302 1 << spa->spa_max_ashift); 1303 /* 1304 * The minimum-size allocation can not fail. 1305 */ 1306 ASSERT3U(attempted, >, 1 << spa->spa_max_ashift); 1307 *max_alloc = attempted - (1 << spa->spa_max_ashift); 1308 } else { 1309 ASSERT0(error); 1310 1311 /* 1312 * We've performed an allocation, so reset the 1313 * alloc trace list. 1314 */ 1315 metaslab_trace_fini(&zal); 1316 metaslab_trace_init(&zal); 1317 } 1318 } 1319 metaslab_trace_fini(&zal); 1320 range_tree_destroy(segs); 1321 } 1322 1323 /* 1324 * The removal thread operates in open context. It iterates over all 1325 * allocated space in the vdev, by loading each metaslab's spacemap. 1326 * For each contiguous segment of allocated space (capping the segment 1327 * size at SPA_MAXBLOCKSIZE), we: 1328 * - Allocate space for it on another vdev. 1329 * - Create a new mapping from the old location to the new location 1330 * (as a record in svr_new_segments). 1331 * - Initiate a logical read zio to get the data off the removing disk. 1332 * - In the read zio's done callback, initiate a logical write zio to 1333 * write it to the new vdev. 1334 * Note that all of this will take effect when a particular TXG syncs. 1335 * The sync thread ensures that all the phys reads and writes for the syncing 1336 * TXG have completed (see spa_txg_zio) and writes the new mappings to disk 1337 * (see vdev_mapping_sync()). 1338 */ 1339 static void 1340 spa_vdev_remove_thread(void *arg) 1341 { 1342 spa_t *spa = arg; 1343 spa_vdev_removal_t *svr = spa->spa_vdev_removal; 1344 vdev_copy_arg_t vca; 1345 uint64_t max_alloc = zfs_remove_max_segment; 1346 uint64_t last_txg = 0; 1347 1348 spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER); 1349 vdev_t *vd = vdev_lookup_top(spa, svr->svr_vdev_id); 1350 vdev_indirect_mapping_t *vim = vd->vdev_indirect_mapping; 1351 uint64_t start_offset = vdev_indirect_mapping_max_offset(vim); 1352 1353 ASSERT3P(vd->vdev_ops, !=, &vdev_indirect_ops); 1354 ASSERT(vdev_is_concrete(vd)); 1355 ASSERT(vd->vdev_removing); 1356 ASSERT(vd->vdev_indirect_config.vic_mapping_object != 0); 1357 ASSERT(vim != NULL); 1358 1359 mutex_init(&vca.vca_lock, NULL, MUTEX_DEFAULT, NULL); 1360 cv_init(&vca.vca_cv, NULL, CV_DEFAULT, NULL); 1361 vca.vca_outstanding_bytes = 0; 1362 1363 mutex_enter(&svr->svr_lock); 1364 1365 /* 1366 * Start from vim_max_offset so we pick up where we left off 1367 * if we are restarting the removal after opening the pool. 1368 */ 1369 uint64_t msi; 1370 for (msi = start_offset >> vd->vdev_ms_shift; 1371 msi < vd->vdev_ms_count && !svr->svr_thread_exit; msi++) { 1372 metaslab_t *msp = vd->vdev_ms[msi]; 1373 ASSERT3U(msi, <=, vd->vdev_ms_count); 1374 1375 ASSERT0(range_tree_space(svr->svr_allocd_segs)); 1376 1377 mutex_enter(&msp->ms_sync_lock); 1378 mutex_enter(&msp->ms_lock); 1379 1380 /* 1381 * Assert nothing in flight -- ms_*tree is empty. 1382 */ 1383 for (int i = 0; i < TXG_SIZE; i++) { 1384 ASSERT0(range_tree_space(msp->ms_allocating[i])); 1385 } 1386 1387 /* 1388 * If the metaslab has ever been allocated from (ms_sm!=NULL), 1389 * read the allocated segments from the space map object 1390 * into svr_allocd_segs. Since we do this while holding 1391 * svr_lock and ms_sync_lock, concurrent frees (which 1392 * would have modified the space map) will wait for us 1393 * to finish loading the spacemap, and then take the 1394 * appropriate action (see free_from_removing_vdev()). 1395 */ 1396 if (msp->ms_sm != NULL) { 1397 VERIFY0(space_map_load(msp->ms_sm, 1398 svr->svr_allocd_segs, SM_ALLOC)); 1399 1400 range_tree_walk(msp->ms_freeing, 1401 range_tree_remove, svr->svr_allocd_segs); 1402 1403 /* 1404 * When we are resuming from a paused removal (i.e. 1405 * when importing a pool with a removal in progress), 1406 * discard any state that we have already processed. 1407 */ 1408 range_tree_clear(svr->svr_allocd_segs, 0, start_offset); 1409 } 1410 mutex_exit(&msp->ms_lock); 1411 mutex_exit(&msp->ms_sync_lock); 1412 1413 vca.vca_msp = msp; 1414 zfs_dbgmsg("copying %llu segments for metaslab %llu", 1415 avl_numnodes(&svr->svr_allocd_segs->rt_root), 1416 msp->ms_id); 1417 1418 while (!svr->svr_thread_exit && 1419 !range_tree_is_empty(svr->svr_allocd_segs)) { 1420 1421 mutex_exit(&svr->svr_lock); 1422 1423 /* 1424 * We need to periodically drop the config lock so that 1425 * writers can get in. Additionally, we can't wait 1426 * for a txg to sync while holding a config lock 1427 * (since a waiting writer could cause a 3-way deadlock 1428 * with the sync thread, which also gets a config 1429 * lock for reader). So we can't hold the config lock 1430 * while calling dmu_tx_assign(). 1431 */ 1432 spa_config_exit(spa, SCL_CONFIG, FTAG); 1433 1434 /* 1435 * This delay will pause the removal around the point 1436 * specified by zfs_removal_suspend_progress. We do this 1437 * solely from the test suite or during debugging. 1438 */ 1439 uint64_t bytes_copied = 1440 spa->spa_removing_phys.sr_copied; 1441 for (int i = 0; i < TXG_SIZE; i++) 1442 bytes_copied += svr->svr_bytes_done[i]; 1443 while (zfs_removal_suspend_progress && 1444 !svr->svr_thread_exit) 1445 delay(hz); 1446 1447 mutex_enter(&vca.vca_lock); 1448 while (vca.vca_outstanding_bytes > 1449 zfs_remove_max_copy_bytes) { 1450 cv_wait(&vca.vca_cv, &vca.vca_lock); 1451 } 1452 mutex_exit(&vca.vca_lock); 1453 1454 dmu_tx_t *tx = 1455 dmu_tx_create_dd(spa_get_dsl(spa)->dp_mos_dir); 1456 1457 VERIFY0(dmu_tx_assign(tx, TXG_WAIT)); 1458 uint64_t txg = dmu_tx_get_txg(tx); 1459 1460 /* 1461 * Reacquire the vdev_config lock. The vdev_t 1462 * that we're removing may have changed, e.g. due 1463 * to a vdev_attach or vdev_detach. 1464 */ 1465 spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER); 1466 vd = vdev_lookup_top(spa, svr->svr_vdev_id); 1467 1468 if (txg != last_txg) 1469 max_alloc = zfs_remove_max_segment; 1470 last_txg = txg; 1471 1472 spa_vdev_copy_impl(vd, svr, &vca, &max_alloc, tx); 1473 1474 dmu_tx_commit(tx); 1475 mutex_enter(&svr->svr_lock); 1476 } 1477 } 1478 1479 mutex_exit(&svr->svr_lock); 1480 1481 spa_config_exit(spa, SCL_CONFIG, FTAG); 1482 1483 /* 1484 * Wait for all copies to finish before cleaning up the vca. 1485 */ 1486 txg_wait_synced(spa->spa_dsl_pool, 0); 1487 ASSERT0(vca.vca_outstanding_bytes); 1488 1489 mutex_destroy(&vca.vca_lock); 1490 cv_destroy(&vca.vca_cv); 1491 1492 if (svr->svr_thread_exit) { 1493 mutex_enter(&svr->svr_lock); 1494 range_tree_vacate(svr->svr_allocd_segs, NULL, NULL); 1495 svr->svr_thread = NULL; 1496 cv_broadcast(&svr->svr_cv); 1497 mutex_exit(&svr->svr_lock); 1498 } else { 1499 ASSERT0(range_tree_space(svr->svr_allocd_segs)); 1500 vdev_remove_complete(spa); 1501 } 1502 } 1503 1504 void 1505 spa_vdev_remove_suspend(spa_t *spa) 1506 { 1507 spa_vdev_removal_t *svr = spa->spa_vdev_removal; 1508 1509 if (svr == NULL) 1510 return; 1511 1512 mutex_enter(&svr->svr_lock); 1513 svr->svr_thread_exit = B_TRUE; 1514 while (svr->svr_thread != NULL) 1515 cv_wait(&svr->svr_cv, &svr->svr_lock); 1516 svr->svr_thread_exit = B_FALSE; 1517 mutex_exit(&svr->svr_lock); 1518 } 1519 1520 /* ARGSUSED */ 1521 static int 1522 spa_vdev_remove_cancel_check(void *arg, dmu_tx_t *tx) 1523 { 1524 spa_t *spa = dmu_tx_pool(tx)->dp_spa; 1525 1526 if (spa->spa_vdev_removal == NULL) 1527 return (ENOTACTIVE); 1528 return (0); 1529 } 1530 1531 /* 1532 * Cancel a removal by freeing all entries from the partial mapping 1533 * and marking the vdev as no longer being removing. 1534 */ 1535 /* ARGSUSED */ 1536 static void 1537 spa_vdev_remove_cancel_sync(void *arg, dmu_tx_t *tx) 1538 { 1539 spa_t *spa = dmu_tx_pool(tx)->dp_spa; 1540 spa_vdev_removal_t *svr = spa->spa_vdev_removal; 1541 vdev_t *vd = vdev_lookup_top(spa, svr->svr_vdev_id); 1542 vdev_indirect_config_t *vic = &vd->vdev_indirect_config; 1543 vdev_indirect_mapping_t *vim = vd->vdev_indirect_mapping; 1544 objset_t *mos = spa->spa_meta_objset; 1545 1546 ASSERT3P(svr->svr_thread, ==, NULL); 1547 1548 spa_feature_decr(spa, SPA_FEATURE_DEVICE_REMOVAL, tx); 1549 if (vdev_obsolete_counts_are_precise(vd)) { 1550 spa_feature_decr(spa, SPA_FEATURE_OBSOLETE_COUNTS, tx); 1551 VERIFY0(zap_remove(spa->spa_meta_objset, vd->vdev_top_zap, 1552 VDEV_TOP_ZAP_OBSOLETE_COUNTS_ARE_PRECISE, tx)); 1553 } 1554 1555 if (vdev_obsolete_sm_object(vd) != 0) { 1556 ASSERT(vd->vdev_obsolete_sm != NULL); 1557 ASSERT3U(vdev_obsolete_sm_object(vd), ==, 1558 space_map_object(vd->vdev_obsolete_sm)); 1559 1560 space_map_free(vd->vdev_obsolete_sm, tx); 1561 VERIFY0(zap_remove(spa->spa_meta_objset, vd->vdev_top_zap, 1562 VDEV_TOP_ZAP_INDIRECT_OBSOLETE_SM, tx)); 1563 space_map_close(vd->vdev_obsolete_sm); 1564 vd->vdev_obsolete_sm = NULL; 1565 spa_feature_decr(spa, SPA_FEATURE_OBSOLETE_COUNTS, tx); 1566 } 1567 for (int i = 0; i < TXG_SIZE; i++) { 1568 ASSERT(list_is_empty(&svr->svr_new_segments[i])); 1569 ASSERT3U(svr->svr_max_offset_to_sync[i], <=, 1570 vdev_indirect_mapping_max_offset(vim)); 1571 } 1572 1573 for (uint64_t msi = 0; msi < vd->vdev_ms_count; msi++) { 1574 metaslab_t *msp = vd->vdev_ms[msi]; 1575 1576 if (msp->ms_start >= vdev_indirect_mapping_max_offset(vim)) 1577 break; 1578 1579 ASSERT0(range_tree_space(svr->svr_allocd_segs)); 1580 1581 mutex_enter(&msp->ms_lock); 1582 1583 /* 1584 * Assert nothing in flight -- ms_*tree is empty. 1585 */ 1586 for (int i = 0; i < TXG_SIZE; i++) 1587 ASSERT0(range_tree_space(msp->ms_allocating[i])); 1588 for (int i = 0; i < TXG_DEFER_SIZE; i++) 1589 ASSERT0(range_tree_space(msp->ms_defer[i])); 1590 ASSERT0(range_tree_space(msp->ms_freed)); 1591 1592 if (msp->ms_sm != NULL) { 1593 mutex_enter(&svr->svr_lock); 1594 VERIFY0(space_map_load(msp->ms_sm, 1595 svr->svr_allocd_segs, SM_ALLOC)); 1596 range_tree_walk(msp->ms_freeing, 1597 range_tree_remove, svr->svr_allocd_segs); 1598 1599 /* 1600 * Clear everything past what has been synced, 1601 * because we have not allocated mappings for it yet. 1602 */ 1603 uint64_t syncd = vdev_indirect_mapping_max_offset(vim); 1604 uint64_t sm_end = msp->ms_sm->sm_start + 1605 msp->ms_sm->sm_size; 1606 if (sm_end > syncd) 1607 range_tree_clear(svr->svr_allocd_segs, 1608 syncd, sm_end - syncd); 1609 1610 mutex_exit(&svr->svr_lock); 1611 } 1612 mutex_exit(&msp->ms_lock); 1613 1614 mutex_enter(&svr->svr_lock); 1615 range_tree_vacate(svr->svr_allocd_segs, 1616 free_mapped_segment_cb, vd); 1617 mutex_exit(&svr->svr_lock); 1618 } 1619 1620 /* 1621 * Note: this must happen after we invoke free_mapped_segment_cb, 1622 * because it adds to the obsolete_segments. 1623 */ 1624 range_tree_vacate(vd->vdev_obsolete_segments, NULL, NULL); 1625 1626 ASSERT3U(vic->vic_mapping_object, ==, 1627 vdev_indirect_mapping_object(vd->vdev_indirect_mapping)); 1628 vdev_indirect_mapping_close(vd->vdev_indirect_mapping); 1629 vd->vdev_indirect_mapping = NULL; 1630 vdev_indirect_mapping_free(mos, vic->vic_mapping_object, tx); 1631 vic->vic_mapping_object = 0; 1632 1633 ASSERT3U(vic->vic_births_object, ==, 1634 vdev_indirect_births_object(vd->vdev_indirect_births)); 1635 vdev_indirect_births_close(vd->vdev_indirect_births); 1636 vd->vdev_indirect_births = NULL; 1637 vdev_indirect_births_free(mos, vic->vic_births_object, tx); 1638 vic->vic_births_object = 0; 1639 1640 /* 1641 * We may have processed some frees from the removing vdev in this 1642 * txg, thus increasing svr_bytes_done; discard that here to 1643 * satisfy the assertions in spa_vdev_removal_destroy(). 1644 * Note that future txg's can not have any bytes_done, because 1645 * future TXG's are only modified from open context, and we have 1646 * already shut down the copying thread. 1647 */ 1648 svr->svr_bytes_done[dmu_tx_get_txg(tx) & TXG_MASK] = 0; 1649 spa_finish_removal(spa, DSS_CANCELED, tx); 1650 1651 vd->vdev_removing = B_FALSE; 1652 vdev_config_dirty(vd); 1653 1654 zfs_dbgmsg("canceled device removal for vdev %llu in %llu", 1655 vd->vdev_id, dmu_tx_get_txg(tx)); 1656 spa_history_log_internal(spa, "vdev remove canceled", tx, 1657 "%s vdev %llu %s", spa_name(spa), 1658 vd->vdev_id, (vd->vdev_path != NULL) ? vd->vdev_path : "-"); 1659 } 1660 1661 int 1662 spa_vdev_remove_cancel(spa_t *spa) 1663 { 1664 spa_vdev_remove_suspend(spa); 1665 1666 if (spa->spa_vdev_removal == NULL) 1667 return (ENOTACTIVE); 1668 1669 uint64_t vdid = spa->spa_vdev_removal->svr_vdev_id; 1670 1671 int error = dsl_sync_task(spa->spa_name, spa_vdev_remove_cancel_check, 1672 spa_vdev_remove_cancel_sync, NULL, 0, 1673 ZFS_SPACE_CHECK_EXTRA_RESERVED); 1674 1675 if (error == 0) { 1676 spa_config_enter(spa, SCL_ALLOC | SCL_VDEV, FTAG, RW_WRITER); 1677 vdev_t *vd = vdev_lookup_top(spa, vdid); 1678 metaslab_group_activate(vd->vdev_mg); 1679 spa_config_exit(spa, SCL_ALLOC | SCL_VDEV, FTAG); 1680 } 1681 1682 return (error); 1683 } 1684 1685 void 1686 svr_sync(spa_t *spa, dmu_tx_t *tx) 1687 { 1688 spa_vdev_removal_t *svr = spa->spa_vdev_removal; 1689 int txgoff = dmu_tx_get_txg(tx) & TXG_MASK; 1690 1691 if (svr == NULL) 1692 return; 1693 1694 /* 1695 * This check is necessary so that we do not dirty the 1696 * DIRECTORY_OBJECT via spa_sync_removing_state() when there 1697 * is nothing to do. Dirtying it every time would prevent us 1698 * from syncing-to-convergence. 1699 */ 1700 if (svr->svr_bytes_done[txgoff] == 0) 1701 return; 1702 1703 /* 1704 * Update progress accounting. 1705 */ 1706 spa->spa_removing_phys.sr_copied += svr->svr_bytes_done[txgoff]; 1707 svr->svr_bytes_done[txgoff] = 0; 1708 1709 spa_sync_removing_state(spa, tx); 1710 } 1711 1712 static void 1713 vdev_remove_make_hole_and_free(vdev_t *vd) 1714 { 1715 uint64_t id = vd->vdev_id; 1716 spa_t *spa = vd->vdev_spa; 1717 vdev_t *rvd = spa->spa_root_vdev; 1718 boolean_t last_vdev = (id == (rvd->vdev_children - 1)); 1719 1720 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 1721 ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL); 1722 1723 vdev_free(vd); 1724 1725 if (last_vdev) { 1726 vdev_compact_children(rvd); 1727 } else { 1728 vd = vdev_alloc_common(spa, id, 0, &vdev_hole_ops); 1729 vdev_add_child(rvd, vd); 1730 } 1731 vdev_config_dirty(rvd); 1732 1733 /* 1734 * Reassess the health of our root vdev. 1735 */ 1736 vdev_reopen(rvd); 1737 } 1738 1739 /* 1740 * Remove a log device. The config lock is held for the specified TXG. 1741 */ 1742 static int 1743 spa_vdev_remove_log(vdev_t *vd, uint64_t *txg) 1744 { 1745 metaslab_group_t *mg = vd->vdev_mg; 1746 spa_t *spa = vd->vdev_spa; 1747 int error = 0; 1748 1749 ASSERT(vd->vdev_islog); 1750 ASSERT(vd == vd->vdev_top); 1751 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 1752 1753 /* 1754 * Stop allocating from this vdev. 1755 */ 1756 metaslab_group_passivate(mg); 1757 1758 /* 1759 * Wait for the youngest allocations and frees to sync, 1760 * and then wait for the deferral of those frees to finish. 1761 */ 1762 spa_vdev_config_exit(spa, NULL, 1763 *txg + TXG_CONCURRENT_STATES + TXG_DEFER_SIZE, 0, FTAG); 1764 1765 /* 1766 * Evacuate the device. We don't hold the config lock as 1767 * writer since we need to do I/O but we do keep the 1768 * spa_namespace_lock held. Once this completes the device 1769 * should no longer have any blocks allocated on it. 1770 */ 1771 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 1772 if (vd->vdev_stat.vs_alloc != 0) 1773 error = spa_reset_logs(spa); 1774 1775 *txg = spa_vdev_config_enter(spa); 1776 1777 if (error != 0) { 1778 metaslab_group_activate(mg); 1779 return (error); 1780 } 1781 ASSERT0(vd->vdev_stat.vs_alloc); 1782 1783 /* 1784 * The evacuation succeeded. Remove any remaining MOS metadata 1785 * associated with this vdev, and wait for these changes to sync. 1786 */ 1787 vd->vdev_removing = B_TRUE; 1788 1789 vdev_dirty_leaves(vd, VDD_DTL, *txg); 1790 vdev_config_dirty(vd); 1791 1792 vdev_metaslab_fini(vd); 1793 1794 spa_history_log_internal(spa, "vdev remove", NULL, 1795 "%s vdev %llu (log) %s", spa_name(spa), vd->vdev_id, 1796 (vd->vdev_path != NULL) ? vd->vdev_path : "-"); 1797 1798 /* Make sure these changes are sync'ed */ 1799 spa_vdev_config_exit(spa, NULL, *txg, 0, FTAG); 1800 1801 /* Stop initializing */ 1802 (void) vdev_initialize_stop_all(vd, VDEV_INITIALIZE_CANCELED); 1803 1804 *txg = spa_vdev_config_enter(spa); 1805 1806 sysevent_t *ev = spa_event_create(spa, vd, NULL, 1807 ESC_ZFS_VDEV_REMOVE_DEV); 1808 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 1809 ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL); 1810 1811 /* The top ZAP should have been destroyed by vdev_remove_empty. */ 1812 ASSERT0(vd->vdev_top_zap); 1813 /* The leaf ZAP should have been destroyed by vdev_dtl_sync. */ 1814 ASSERT0(vd->vdev_leaf_zap); 1815 1816 (void) vdev_label_init(vd, 0, VDEV_LABEL_REMOVE); 1817 1818 if (list_link_active(&vd->vdev_state_dirty_node)) 1819 vdev_state_clean(vd); 1820 if (list_link_active(&vd->vdev_config_dirty_node)) 1821 vdev_config_clean(vd); 1822 1823 ASSERT0(vd->vdev_stat.vs_alloc); 1824 1825 /* 1826 * Clean up the vdev namespace. 1827 */ 1828 vdev_remove_make_hole_and_free(vd); 1829 1830 if (ev != NULL) 1831 spa_event_post(ev); 1832 1833 return (0); 1834 } 1835 1836 static int 1837 spa_vdev_remove_top_check(vdev_t *vd) 1838 { 1839 spa_t *spa = vd->vdev_spa; 1840 1841 if (vd != vd->vdev_top) 1842 return (SET_ERROR(ENOTSUP)); 1843 1844 if (!spa_feature_is_enabled(spa, SPA_FEATURE_DEVICE_REMOVAL)) 1845 return (SET_ERROR(ENOTSUP)); 1846 1847 /* available space in the pool's normal class */ 1848 uint64_t available = dsl_dir_space_available( 1849 spa->spa_dsl_pool->dp_root_dir, NULL, 0, B_TRUE); 1850 1851 metaslab_class_t *mc = vd->vdev_mg->mg_class; 1852 1853 /* 1854 * When removing a vdev from an allocation class that has 1855 * remaining vdevs, include available space from the class. 1856 */ 1857 if (mc != spa_normal_class(spa) && mc->mc_groups > 1) { 1858 uint64_t class_avail = metaslab_class_get_space(mc) - 1859 metaslab_class_get_alloc(mc); 1860 1861 /* add class space, adjusted for overhead */ 1862 available += (class_avail * 94) / 100; 1863 } 1864 1865 /* 1866 * There has to be enough free space to remove the 1867 * device and leave double the "slop" space (i.e. we 1868 * must leave at least 3% of the pool free, in addition to 1869 * the normal slop space). 1870 */ 1871 if (available < vd->vdev_stat.vs_dspace + spa_get_slop_space(spa)) { 1872 return (SET_ERROR(ENOSPC)); 1873 } 1874 1875 /* 1876 * There can not be a removal in progress. 1877 */ 1878 if (spa->spa_removing_phys.sr_state == DSS_SCANNING) 1879 return (SET_ERROR(EBUSY)); 1880 1881 /* 1882 * The device must have all its data. 1883 */ 1884 if (!vdev_dtl_empty(vd, DTL_MISSING) || 1885 !vdev_dtl_empty(vd, DTL_OUTAGE)) 1886 return (SET_ERROR(EBUSY)); 1887 1888 /* 1889 * The device must be healthy. 1890 */ 1891 if (!vdev_readable(vd)) 1892 return (SET_ERROR(EIO)); 1893 1894 /* 1895 * All vdevs in normal class must have the same ashift. 1896 */ 1897 if (spa->spa_max_ashift != spa->spa_min_ashift) { 1898 return (SET_ERROR(EINVAL)); 1899 } 1900 1901 /* 1902 * All vdevs in normal class must have the same ashift 1903 * and not be raidz. 1904 */ 1905 vdev_t *rvd = spa->spa_root_vdev; 1906 int num_indirect = 0; 1907 for (uint64_t id = 0; id < rvd->vdev_children; id++) { 1908 vdev_t *cvd = rvd->vdev_child[id]; 1909 if (cvd->vdev_ashift != 0 && !cvd->vdev_islog) 1910 ASSERT3U(cvd->vdev_ashift, ==, spa->spa_max_ashift); 1911 if (cvd->vdev_ops == &vdev_indirect_ops) 1912 num_indirect++; 1913 if (!vdev_is_concrete(cvd)) 1914 continue; 1915 if (cvd->vdev_ops == &vdev_raidz_ops) 1916 return (SET_ERROR(EINVAL)); 1917 /* 1918 * Need the mirror to be mirror of leaf vdevs only 1919 */ 1920 if (cvd->vdev_ops == &vdev_mirror_ops) { 1921 for (uint64_t cid = 0; 1922 cid < cvd->vdev_children; cid++) { 1923 vdev_t *tmp = cvd->vdev_child[cid]; 1924 if (!tmp->vdev_ops->vdev_op_leaf) 1925 return (SET_ERROR(EINVAL)); 1926 } 1927 } 1928 } 1929 1930 return (0); 1931 } 1932 1933 /* 1934 * Initiate removal of a top-level vdev, reducing the total space in the pool. 1935 * The config lock is held for the specified TXG. Once initiated, 1936 * evacuation of all allocated space (copying it to other vdevs) happens 1937 * in the background (see spa_vdev_remove_thread()), and can be canceled 1938 * (see spa_vdev_remove_cancel()). If successful, the vdev will 1939 * be transformed to an indirect vdev (see spa_vdev_remove_complete()). 1940 */ 1941 static int 1942 spa_vdev_remove_top(vdev_t *vd, uint64_t *txg) 1943 { 1944 spa_t *spa = vd->vdev_spa; 1945 int error; 1946 1947 /* 1948 * Check for errors up-front, so that we don't waste time 1949 * passivating the metaslab group and clearing the ZIL if there 1950 * are errors. 1951 */ 1952 error = spa_vdev_remove_top_check(vd); 1953 if (error != 0) 1954 return (error); 1955 1956 /* 1957 * Stop allocating from this vdev. Note that we must check 1958 * that this is not the only device in the pool before 1959 * passivating, otherwise we will not be able to make 1960 * progress because we can't allocate from any vdevs. 1961 * The above check for sufficient free space serves this 1962 * purpose. 1963 */ 1964 metaslab_group_t *mg = vd->vdev_mg; 1965 metaslab_group_passivate(mg); 1966 1967 /* 1968 * Wait for the youngest allocations and frees to sync, 1969 * and then wait for the deferral of those frees to finish. 1970 */ 1971 spa_vdev_config_exit(spa, NULL, 1972 *txg + TXG_CONCURRENT_STATES + TXG_DEFER_SIZE, 0, FTAG); 1973 1974 /* 1975 * We must ensure that no "stubby" log blocks are allocated 1976 * on the device to be removed. These blocks could be 1977 * written at any time, including while we are in the middle 1978 * of copying them. 1979 */ 1980 error = spa_reset_logs(spa); 1981 1982 /* 1983 * We stop any initializing that is currently in progress but leave 1984 * the state as "active". This will allow the initializing to resume 1985 * if the removal is canceled sometime later. 1986 */ 1987 vdev_initialize_stop_all(vd, VDEV_INITIALIZE_ACTIVE); 1988 1989 *txg = spa_vdev_config_enter(spa); 1990 1991 /* 1992 * Things might have changed while the config lock was dropped 1993 * (e.g. space usage). Check for errors again. 1994 */ 1995 if (error == 0) 1996 error = spa_vdev_remove_top_check(vd); 1997 1998 if (error != 0) { 1999 metaslab_group_activate(mg); 2000 spa_async_request(spa, SPA_ASYNC_INITIALIZE_RESTART); 2001 return (error); 2002 } 2003 2004 vd->vdev_removing = B_TRUE; 2005 2006 vdev_dirty_leaves(vd, VDD_DTL, *txg); 2007 vdev_config_dirty(vd); 2008 dmu_tx_t *tx = dmu_tx_create_assigned(spa->spa_dsl_pool, *txg); 2009 dsl_sync_task_nowait(spa->spa_dsl_pool, 2010 vdev_remove_initiate_sync, 2011 (void *)(uintptr_t)vd->vdev_id, 0, ZFS_SPACE_CHECK_NONE, tx); 2012 dmu_tx_commit(tx); 2013 2014 return (0); 2015 } 2016 2017 /* 2018 * Remove a device from the pool. 2019 * 2020 * Removing a device from the vdev namespace requires several steps 2021 * and can take a significant amount of time. As a result we use 2022 * the spa_vdev_config_[enter/exit] functions which allow us to 2023 * grab and release the spa_config_lock while still holding the namespace 2024 * lock. During each step the configuration is synced out. 2025 */ 2026 int 2027 spa_vdev_remove(spa_t *spa, uint64_t guid, boolean_t unspare) 2028 { 2029 vdev_t *vd; 2030 nvlist_t **spares, **l2cache, *nv; 2031 uint64_t txg = 0; 2032 uint_t nspares, nl2cache; 2033 int error = 0; 2034 boolean_t locked = MUTEX_HELD(&spa_namespace_lock); 2035 sysevent_t *ev = NULL; 2036 2037 ASSERT(spa_writeable(spa)); 2038 2039 if (!locked) 2040 txg = spa_vdev_enter(spa); 2041 2042 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 2043 if (spa_feature_is_active(spa, SPA_FEATURE_POOL_CHECKPOINT)) { 2044 error = (spa_has_checkpoint(spa)) ? 2045 ZFS_ERR_CHECKPOINT_EXISTS : ZFS_ERR_DISCARDING_CHECKPOINT; 2046 2047 if (!locked) 2048 return (spa_vdev_exit(spa, NULL, txg, error)); 2049 2050 return (error); 2051 } 2052 2053 vd = spa_lookup_by_guid(spa, guid, B_FALSE); 2054 2055 if (spa->spa_spares.sav_vdevs != NULL && 2056 nvlist_lookup_nvlist_array(spa->spa_spares.sav_config, 2057 ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0 && 2058 (nv = spa_nvlist_lookup_by_guid(spares, nspares, guid)) != NULL) { 2059 /* 2060 * Only remove the hot spare if it's not currently in use 2061 * in this pool. 2062 */ 2063 if (vd == NULL || unspare) { 2064 char *nvstr = fnvlist_lookup_string(nv, 2065 ZPOOL_CONFIG_PATH); 2066 spa_history_log_internal(spa, "vdev remove", NULL, 2067 "%s vdev (%s) %s", spa_name(spa), 2068 VDEV_TYPE_SPARE, nvstr); 2069 if (vd == NULL) 2070 vd = spa_lookup_by_guid(spa, guid, B_TRUE); 2071 ev = spa_event_create(spa, vd, NULL, 2072 ESC_ZFS_VDEV_REMOVE_AUX); 2073 spa_vdev_remove_aux(spa->spa_spares.sav_config, 2074 ZPOOL_CONFIG_SPARES, spares, nspares, nv); 2075 spa_load_spares(spa); 2076 spa->spa_spares.sav_sync = B_TRUE; 2077 } else { 2078 error = SET_ERROR(EBUSY); 2079 } 2080 } else if (spa->spa_l2cache.sav_vdevs != NULL && 2081 nvlist_lookup_nvlist_array(spa->spa_l2cache.sav_config, 2082 ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0 && 2083 (nv = spa_nvlist_lookup_by_guid(l2cache, nl2cache, guid)) != NULL) { 2084 char *nvstr = fnvlist_lookup_string(nv, ZPOOL_CONFIG_PATH); 2085 spa_history_log_internal(spa, "vdev remove", NULL, 2086 "%s vdev (%s) %s", spa_name(spa), VDEV_TYPE_L2CACHE, nvstr); 2087 /* 2088 * Cache devices can always be removed. 2089 */ 2090 vd = spa_lookup_by_guid(spa, guid, B_TRUE); 2091 ev = spa_event_create(spa, vd, NULL, ESC_ZFS_VDEV_REMOVE_AUX); 2092 spa_vdev_remove_aux(spa->spa_l2cache.sav_config, 2093 ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache, nv); 2094 spa_load_l2cache(spa); 2095 spa->spa_l2cache.sav_sync = B_TRUE; 2096 } else if (vd != NULL && vd->vdev_islog) { 2097 ASSERT(!locked); 2098 error = spa_vdev_remove_log(vd, &txg); 2099 } else if (vd != NULL) { 2100 ASSERT(!locked); 2101 error = spa_vdev_remove_top(vd, &txg); 2102 } else { 2103 /* 2104 * There is no vdev of any kind with the specified guid. 2105 */ 2106 error = SET_ERROR(ENOENT); 2107 } 2108 2109 if (!locked) 2110 error = spa_vdev_exit(spa, NULL, txg, error); 2111 2112 if (ev != NULL) { 2113 if (error != 0) { 2114 spa_event_discard(ev); 2115 } else { 2116 spa_event_post(ev); 2117 } 2118 } 2119 2120 return (error); 2121 } 2122 2123 int 2124 spa_removal_get_stats(spa_t *spa, pool_removal_stat_t *prs) 2125 { 2126 prs->prs_state = spa->spa_removing_phys.sr_state; 2127 2128 if (prs->prs_state == DSS_NONE) 2129 return (SET_ERROR(ENOENT)); 2130 2131 prs->prs_removing_vdev = spa->spa_removing_phys.sr_removing_vdev; 2132 prs->prs_start_time = spa->spa_removing_phys.sr_start_time; 2133 prs->prs_end_time = spa->spa_removing_phys.sr_end_time; 2134 prs->prs_to_copy = spa->spa_removing_phys.sr_to_copy; 2135 prs->prs_copied = spa->spa_removing_phys.sr_copied; 2136 2137 if (spa->spa_vdev_removal != NULL) { 2138 for (int i = 0; i < TXG_SIZE; i++) { 2139 prs->prs_copied += 2140 spa->spa_vdev_removal->svr_bytes_done[i]; 2141 } 2142 } 2143 2144 prs->prs_mapping_memory = 0; 2145 uint64_t indirect_vdev_id = 2146 spa->spa_removing_phys.sr_prev_indirect_vdev; 2147 while (indirect_vdev_id != -1) { 2148 vdev_t *vd = spa->spa_root_vdev->vdev_child[indirect_vdev_id]; 2149 vdev_indirect_config_t *vic = &vd->vdev_indirect_config; 2150 vdev_indirect_mapping_t *vim = vd->vdev_indirect_mapping; 2151 2152 ASSERT3P(vd->vdev_ops, ==, &vdev_indirect_ops); 2153 prs->prs_mapping_memory += vdev_indirect_mapping_size(vim); 2154 indirect_vdev_id = vic->vic_prev_indirect_vdev; 2155 } 2156 2157 return (0); 2158 } 2159