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Diffstat (limited to 'module/zfs/vdev_removal.c')
| -rw-r--r-- | module/zfs/vdev_removal.c | 2340 |
1 files changed, 2340 insertions, 0 deletions
diff --git a/module/zfs/vdev_removal.c b/module/zfs/vdev_removal.c new file mode 100644 index 000000000000..56e420871f61 --- /dev/null +++ b/module/zfs/vdev_removal.c @@ -0,0 +1,2340 @@ +/* + * CDDL HEADER START + * + * The contents of this file are subject to the terms of the + * Common Development and Distribution License (the "License"). + * You may not use this file except in compliance with the License. + * + * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE + * or http://www.opensolaris.org/os/licensing. + * See the License for the specific language governing permissions + * and limitations under the License. + * + * When distributing Covered Code, include this CDDL HEADER in each + * file and include the License file at usr/src/OPENSOLARIS.LICENSE. + * If applicable, add the following below this CDDL HEADER, with the + * fields enclosed by brackets "[]" replaced with your own identifying + * information: Portions Copyright [yyyy] [name of copyright owner] + * + * CDDL HEADER END + */ + +/* + * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2011, 2019 by Delphix. All rights reserved. + * Copyright (c) 2019, loli10K <ezomori.nozomu@gmail.com>. All rights reserved. + */ + +#include <sys/zfs_context.h> +#include <sys/spa_impl.h> +#include <sys/dmu.h> +#include <sys/dmu_tx.h> +#include <sys/zap.h> +#include <sys/vdev_impl.h> +#include <sys/metaslab.h> +#include <sys/metaslab_impl.h> +#include <sys/uberblock_impl.h> +#include <sys/txg.h> +#include <sys/avl.h> +#include <sys/bpobj.h> +#include <sys/dsl_pool.h> +#include <sys/dsl_synctask.h> +#include <sys/dsl_dir.h> +#include <sys/arc.h> +#include <sys/zfeature.h> +#include <sys/vdev_indirect_births.h> +#include <sys/vdev_indirect_mapping.h> +#include <sys/abd.h> +#include <sys/vdev_initialize.h> +#include <sys/vdev_trim.h> +#include <sys/trace_zfs.h> + +/* + * This file contains the necessary logic to remove vdevs from a + * storage pool. Currently, the only devices that can be removed + * are log, cache, and spare devices; and top level vdevs from a pool + * w/o raidz or mirrors. (Note that members of a mirror can be removed + * by the detach operation.) + * + * Log vdevs are removed by evacuating them and then turning the vdev + * into a hole vdev while holding spa config locks. + * + * Top level vdevs are removed and converted into an indirect vdev via + * a multi-step process: + * + * - Disable allocations from this device (spa_vdev_remove_top). + * + * - From a new thread (spa_vdev_remove_thread), copy data from + * the removing vdev to a different vdev. The copy happens in open + * context (spa_vdev_copy_impl) and issues a sync task + * (vdev_mapping_sync) so the sync thread can update the partial + * indirect mappings in core and on disk. + * + * - If a free happens during a removal, it is freed from the + * removing vdev, and if it has already been copied, from the new + * location as well (free_from_removing_vdev). + * + * - After the removal is completed, the copy thread converts the vdev + * into an indirect vdev (vdev_remove_complete) before instructing + * the sync thread to destroy the space maps and finish the removal + * (spa_finish_removal). + */ + +typedef struct vdev_copy_arg { + metaslab_t *vca_msp; + uint64_t vca_outstanding_bytes; + uint64_t vca_read_error_bytes; + uint64_t vca_write_error_bytes; + kcondvar_t vca_cv; + kmutex_t vca_lock; +} vdev_copy_arg_t; + +/* + * The maximum amount of memory we can use for outstanding i/o while + * doing a device removal. This determines how much i/o we can have + * in flight concurrently. + */ +int zfs_remove_max_copy_bytes = 64 * 1024 * 1024; + +/* + * The largest contiguous segment that we will attempt to allocate when + * removing a device. This can be no larger than SPA_MAXBLOCKSIZE. If + * there is a performance problem with attempting to allocate large blocks, + * consider decreasing this. + * + * See also the accessor function spa_remove_max_segment(). + */ +int zfs_remove_max_segment = SPA_MAXBLOCKSIZE; + +/* + * Ignore hard IO errors during device removal. When set if a device + * encounters hard IO error during the removal process the removal will + * not be cancelled. This can result in a normally recoverable block + * becoming permanently damaged and is not recommended. + */ +int zfs_removal_ignore_errors = 0; + +/* + * Allow a remap segment to span free chunks of at most this size. The main + * impact of a larger span is that we will read and write larger, more + * contiguous chunks, with more "unnecessary" data -- trading off bandwidth + * for iops. The value here was chosen to align with + * zfs_vdev_read_gap_limit, which is a similar concept when doing regular + * reads (but there's no reason it has to be the same). + * + * Additionally, a higher span will have the following relatively minor + * effects: + * - the mapping will be smaller, since one entry can cover more allocated + * segments + * - more of the fragmentation in the removing device will be preserved + * - we'll do larger allocations, which may fail and fall back on smaller + * allocations + */ +int vdev_removal_max_span = 32 * 1024; + +/* + * This is used by the test suite so that it can ensure that certain + * actions happen while in the middle of a removal. + */ +int zfs_removal_suspend_progress = 0; + +#define VDEV_REMOVAL_ZAP_OBJS "lzap" + +static void spa_vdev_remove_thread(void *arg); +static int spa_vdev_remove_cancel_impl(spa_t *spa); + +static void +spa_sync_removing_state(spa_t *spa, dmu_tx_t *tx) +{ + VERIFY0(zap_update(spa->spa_dsl_pool->dp_meta_objset, + DMU_POOL_DIRECTORY_OBJECT, + DMU_POOL_REMOVING, sizeof (uint64_t), + sizeof (spa->spa_removing_phys) / sizeof (uint64_t), + &spa->spa_removing_phys, tx)); +} + +static nvlist_t * +spa_nvlist_lookup_by_guid(nvlist_t **nvpp, int count, uint64_t target_guid) +{ + for (int i = 0; i < count; i++) { + uint64_t guid = + fnvlist_lookup_uint64(nvpp[i], ZPOOL_CONFIG_GUID); + + if (guid == target_guid) + return (nvpp[i]); + } + + return (NULL); +} + +static void +spa_vdev_remove_aux(nvlist_t *config, char *name, nvlist_t **dev, int count, + nvlist_t *dev_to_remove) +{ + nvlist_t **newdev = NULL; + + if (count > 1) + newdev = kmem_alloc((count - 1) * sizeof (void *), KM_SLEEP); + + for (int i = 0, j = 0; i < count; i++) { + if (dev[i] == dev_to_remove) + continue; + VERIFY(nvlist_dup(dev[i], &newdev[j++], KM_SLEEP) == 0); + } + + VERIFY(nvlist_remove(config, name, DATA_TYPE_NVLIST_ARRAY) == 0); + VERIFY(nvlist_add_nvlist_array(config, name, newdev, count - 1) == 0); + + for (int i = 0; i < count - 1; i++) + nvlist_free(newdev[i]); + + if (count > 1) + kmem_free(newdev, (count - 1) * sizeof (void *)); +} + +static spa_vdev_removal_t * +spa_vdev_removal_create(vdev_t *vd) +{ + spa_vdev_removal_t *svr = kmem_zalloc(sizeof (*svr), KM_SLEEP); + mutex_init(&svr->svr_lock, NULL, MUTEX_DEFAULT, NULL); + cv_init(&svr->svr_cv, NULL, CV_DEFAULT, NULL); + svr->svr_allocd_segs = range_tree_create(NULL, RANGE_SEG64, NULL, 0, 0); + svr->svr_vdev_id = vd->vdev_id; + + for (int i = 0; i < TXG_SIZE; i++) { + svr->svr_frees[i] = range_tree_create(NULL, RANGE_SEG64, NULL, + 0, 0); + list_create(&svr->svr_new_segments[i], + sizeof (vdev_indirect_mapping_entry_t), + offsetof(vdev_indirect_mapping_entry_t, vime_node)); + } + + return (svr); +} + +void +spa_vdev_removal_destroy(spa_vdev_removal_t *svr) +{ + for (int i = 0; i < TXG_SIZE; i++) { + ASSERT0(svr->svr_bytes_done[i]); + ASSERT0(svr->svr_max_offset_to_sync[i]); + range_tree_destroy(svr->svr_frees[i]); + list_destroy(&svr->svr_new_segments[i]); + } + + range_tree_destroy(svr->svr_allocd_segs); + mutex_destroy(&svr->svr_lock); + cv_destroy(&svr->svr_cv); + kmem_free(svr, sizeof (*svr)); +} + +/* + * This is called as a synctask in the txg in which we will mark this vdev + * as removing (in the config stored in the MOS). + * + * It begins the evacuation of a toplevel vdev by: + * - initializing the spa_removing_phys which tracks this removal + * - computing the amount of space to remove for accounting purposes + * - dirtying all dbufs in the spa_config_object + * - creating the spa_vdev_removal + * - starting the spa_vdev_remove_thread + */ +static void +vdev_remove_initiate_sync(void *arg, dmu_tx_t *tx) +{ + int vdev_id = (uintptr_t)arg; + spa_t *spa = dmu_tx_pool(tx)->dp_spa; + vdev_t *vd = vdev_lookup_top(spa, vdev_id); + vdev_indirect_config_t *vic = &vd->vdev_indirect_config; + objset_t *mos = spa->spa_dsl_pool->dp_meta_objset; + spa_vdev_removal_t *svr = NULL; + uint64_t txg __maybe_unused = dmu_tx_get_txg(tx); + + ASSERT3P(vd->vdev_ops, !=, &vdev_raidz_ops); + svr = spa_vdev_removal_create(vd); + + ASSERT(vd->vdev_removing); + ASSERT3P(vd->vdev_indirect_mapping, ==, NULL); + + spa_feature_incr(spa, SPA_FEATURE_DEVICE_REMOVAL, tx); + if (spa_feature_is_enabled(spa, SPA_FEATURE_OBSOLETE_COUNTS)) { + /* + * By activating the OBSOLETE_COUNTS feature, we prevent + * the pool from being downgraded and ensure that the + * refcounts are precise. + */ + spa_feature_incr(spa, SPA_FEATURE_OBSOLETE_COUNTS, tx); + uint64_t one = 1; + VERIFY0(zap_add(spa->spa_meta_objset, vd->vdev_top_zap, + VDEV_TOP_ZAP_OBSOLETE_COUNTS_ARE_PRECISE, sizeof (one), 1, + &one, tx)); + boolean_t are_precise __maybe_unused; + ASSERT0(vdev_obsolete_counts_are_precise(vd, &are_precise)); + ASSERT3B(are_precise, ==, B_TRUE); + } + + vic->vic_mapping_object = vdev_indirect_mapping_alloc(mos, tx); + vd->vdev_indirect_mapping = + vdev_indirect_mapping_open(mos, vic->vic_mapping_object); + vic->vic_births_object = vdev_indirect_births_alloc(mos, tx); + vd->vdev_indirect_births = + vdev_indirect_births_open(mos, vic->vic_births_object); + spa->spa_removing_phys.sr_removing_vdev = vd->vdev_id; + spa->spa_removing_phys.sr_start_time = gethrestime_sec(); + spa->spa_removing_phys.sr_end_time = 0; + spa->spa_removing_phys.sr_state = DSS_SCANNING; + spa->spa_removing_phys.sr_to_copy = 0; + spa->spa_removing_phys.sr_copied = 0; + + /* + * Note: We can't use vdev_stat's vs_alloc for sr_to_copy, because + * there may be space in the defer tree, which is free, but still + * counted in vs_alloc. + */ + for (uint64_t i = 0; i < vd->vdev_ms_count; i++) { + metaslab_t *ms = vd->vdev_ms[i]; + if (ms->ms_sm == NULL) + continue; + + spa->spa_removing_phys.sr_to_copy += + metaslab_allocated_space(ms); + + /* + * Space which we are freeing this txg does not need to + * be copied. + */ + spa->spa_removing_phys.sr_to_copy -= + range_tree_space(ms->ms_freeing); + + ASSERT0(range_tree_space(ms->ms_freed)); + for (int t = 0; t < TXG_SIZE; t++) + ASSERT0(range_tree_space(ms->ms_allocating[t])); + } + + /* + * Sync tasks are called before metaslab_sync(), so there should + * be no already-synced metaslabs in the TXG_CLEAN list. + */ + ASSERT3P(txg_list_head(&vd->vdev_ms_list, TXG_CLEAN(txg)), ==, NULL); + + spa_sync_removing_state(spa, tx); + + /* + * All blocks that we need to read the most recent mapping must be + * stored on concrete vdevs. Therefore, we must dirty anything that + * is read before spa_remove_init(). Specifically, the + * spa_config_object. (Note that although we already modified the + * spa_config_object in spa_sync_removing_state, that may not have + * modified all blocks of the object.) + */ + dmu_object_info_t doi; + VERIFY0(dmu_object_info(mos, DMU_POOL_DIRECTORY_OBJECT, &doi)); + for (uint64_t offset = 0; offset < doi.doi_max_offset; ) { + dmu_buf_t *dbuf; + VERIFY0(dmu_buf_hold(mos, DMU_POOL_DIRECTORY_OBJECT, + offset, FTAG, &dbuf, 0)); + dmu_buf_will_dirty(dbuf, tx); + offset += dbuf->db_size; + dmu_buf_rele(dbuf, FTAG); + } + + /* + * Now that we've allocated the im_object, dirty the vdev to ensure + * that the object gets written to the config on disk. + */ + vdev_config_dirty(vd); + + zfs_dbgmsg("starting removal thread for vdev %llu (%px) in txg %llu " + "im_obj=%llu", vd->vdev_id, vd, dmu_tx_get_txg(tx), + vic->vic_mapping_object); + + spa_history_log_internal(spa, "vdev remove started", tx, + "%s vdev %llu %s", spa_name(spa), (u_longlong_t)vd->vdev_id, + (vd->vdev_path != NULL) ? vd->vdev_path : "-"); + /* + * Setting spa_vdev_removal causes subsequent frees to call + * free_from_removing_vdev(). Note that we don't need any locking + * because we are the sync thread, and metaslab_free_impl() is only + * called from syncing context (potentially from a zio taskq thread, + * but in any case only when there are outstanding free i/os, which + * there are not). + */ + ASSERT3P(spa->spa_vdev_removal, ==, NULL); + spa->spa_vdev_removal = svr; + svr->svr_thread = thread_create(NULL, 0, + spa_vdev_remove_thread, spa, 0, &p0, TS_RUN, minclsyspri); +} + +/* + * When we are opening a pool, we must read the mapping for each + * indirect vdev in order from most recently removed to least + * recently removed. We do this because the blocks for the mapping + * of older indirect vdevs may be stored on more recently removed vdevs. + * In order to read each indirect mapping object, we must have + * initialized all more recently removed vdevs. + */ +int +spa_remove_init(spa_t *spa) +{ + int error; + + error = zap_lookup(spa->spa_dsl_pool->dp_meta_objset, + DMU_POOL_DIRECTORY_OBJECT, + DMU_POOL_REMOVING, sizeof (uint64_t), + sizeof (spa->spa_removing_phys) / sizeof (uint64_t), + &spa->spa_removing_phys); + + if (error == ENOENT) { + spa->spa_removing_phys.sr_state = DSS_NONE; + spa->spa_removing_phys.sr_removing_vdev = -1; + spa->spa_removing_phys.sr_prev_indirect_vdev = -1; + spa->spa_indirect_vdevs_loaded = B_TRUE; + return (0); + } else if (error != 0) { + return (error); + } + + if (spa->spa_removing_phys.sr_state == DSS_SCANNING) { + /* + * We are currently removing a vdev. Create and + * initialize a spa_vdev_removal_t from the bonus + * buffer of the removing vdevs vdev_im_object, and + * initialize its partial mapping. + */ + spa_config_enter(spa, SCL_STATE, FTAG, RW_READER); + vdev_t *vd = vdev_lookup_top(spa, + spa->spa_removing_phys.sr_removing_vdev); + + if (vd == NULL) { + spa_config_exit(spa, SCL_STATE, FTAG); + return (EINVAL); + } + + vdev_indirect_config_t *vic = &vd->vdev_indirect_config; + + ASSERT(vdev_is_concrete(vd)); + spa_vdev_removal_t *svr = spa_vdev_removal_create(vd); + ASSERT3U(svr->svr_vdev_id, ==, vd->vdev_id); + ASSERT(vd->vdev_removing); + + vd->vdev_indirect_mapping = vdev_indirect_mapping_open( + spa->spa_meta_objset, vic->vic_mapping_object); + vd->vdev_indirect_births = vdev_indirect_births_open( + spa->spa_meta_objset, vic->vic_births_object); + spa_config_exit(spa, SCL_STATE, FTAG); + + spa->spa_vdev_removal = svr; + } + + spa_config_enter(spa, SCL_STATE, FTAG, RW_READER); + uint64_t indirect_vdev_id = + spa->spa_removing_phys.sr_prev_indirect_vdev; + while (indirect_vdev_id != UINT64_MAX) { + vdev_t *vd = vdev_lookup_top(spa, indirect_vdev_id); + vdev_indirect_config_t *vic = &vd->vdev_indirect_config; + + ASSERT3P(vd->vdev_ops, ==, &vdev_indirect_ops); + vd->vdev_indirect_mapping = vdev_indirect_mapping_open( + spa->spa_meta_objset, vic->vic_mapping_object); + vd->vdev_indirect_births = vdev_indirect_births_open( + spa->spa_meta_objset, vic->vic_births_object); + + indirect_vdev_id = vic->vic_prev_indirect_vdev; + } + spa_config_exit(spa, SCL_STATE, FTAG); + + /* + * Now that we've loaded all the indirect mappings, we can allow + * reads from other blocks (e.g. via predictive prefetch). + */ + spa->spa_indirect_vdevs_loaded = B_TRUE; + return (0); +} + +void +spa_restart_removal(spa_t *spa) +{ + spa_vdev_removal_t *svr = spa->spa_vdev_removal; + + if (svr == NULL) + return; + + /* + * In general when this function is called there is no + * removal thread running. The only scenario where this + * is not true is during spa_import() where this function + * is called twice [once from spa_import_impl() and + * spa_async_resume()]. Thus, in the scenario where we + * import a pool that has an ongoing removal we don't + * want to spawn a second thread. + */ + if (svr->svr_thread != NULL) + return; + + if (!spa_writeable(spa)) + return; + + zfs_dbgmsg("restarting removal of %llu", svr->svr_vdev_id); + svr->svr_thread = thread_create(NULL, 0, spa_vdev_remove_thread, spa, + 0, &p0, TS_RUN, minclsyspri); +} + +/* + * Process freeing from a device which is in the middle of being removed. + * We must handle this carefully so that we attempt to copy freed data, + * and we correctly free already-copied data. + */ +void +free_from_removing_vdev(vdev_t *vd, uint64_t offset, uint64_t size) +{ + spa_t *spa = vd->vdev_spa; + spa_vdev_removal_t *svr = spa->spa_vdev_removal; + vdev_indirect_mapping_t *vim = vd->vdev_indirect_mapping; + uint64_t txg = spa_syncing_txg(spa); + uint64_t max_offset_yet = 0; + + ASSERT(vd->vdev_indirect_config.vic_mapping_object != 0); + ASSERT3U(vd->vdev_indirect_config.vic_mapping_object, ==, + vdev_indirect_mapping_object(vim)); + ASSERT3U(vd->vdev_id, ==, svr->svr_vdev_id); + + mutex_enter(&svr->svr_lock); + + /* + * Remove the segment from the removing vdev's spacemap. This + * ensures that we will not attempt to copy this space (if the + * removal thread has not yet visited it), and also ensures + * that we know what is actually allocated on the new vdevs + * (needed if we cancel the removal). + * + * Note: we must do the metaslab_free_concrete() with the svr_lock + * held, so that the remove_thread can not load this metaslab and then + * visit this offset between the time that we metaslab_free_concrete() + * and when we check to see if it has been visited. + * + * Note: The checkpoint flag is set to false as having/taking + * a checkpoint and removing a device can't happen at the same + * time. + */ + ASSERT(!spa_has_checkpoint(spa)); + metaslab_free_concrete(vd, offset, size, B_FALSE); + + uint64_t synced_size = 0; + uint64_t synced_offset = 0; + uint64_t max_offset_synced = vdev_indirect_mapping_max_offset(vim); + if (offset < max_offset_synced) { + /* + * The mapping for this offset is already on disk. + * Free from the new location. + * + * Note that we use svr_max_synced_offset because it is + * updated atomically with respect to the in-core mapping. + * By contrast, vim_max_offset is not. + * + * This block may be split between a synced entry and an + * in-flight or unvisited entry. Only process the synced + * portion of it here. + */ + synced_size = MIN(size, max_offset_synced - offset); + synced_offset = offset; + + ASSERT3U(max_offset_yet, <=, max_offset_synced); + max_offset_yet = max_offset_synced; + + DTRACE_PROBE3(remove__free__synced, + spa_t *, spa, + uint64_t, offset, + uint64_t, synced_size); + + size -= synced_size; + offset += synced_size; + } + + /* + * Look at all in-flight txgs starting from the currently syncing one + * and see if a section of this free is being copied. By starting from + * this txg and iterating forward, we might find that this region + * was copied in two different txgs and handle it appropriately. + */ + for (int i = 0; i < TXG_CONCURRENT_STATES; i++) { + int txgoff = (txg + i) & TXG_MASK; + if (size > 0 && offset < svr->svr_max_offset_to_sync[txgoff]) { + /* + * The mapping for this offset is in flight, and + * will be synced in txg+i. + */ + uint64_t inflight_size = MIN(size, + svr->svr_max_offset_to_sync[txgoff] - offset); + + DTRACE_PROBE4(remove__free__inflight, + spa_t *, spa, + uint64_t, offset, + uint64_t, inflight_size, + uint64_t, txg + i); + + /* + * We copy data in order of increasing offset. + * Therefore the max_offset_to_sync[] must increase + * (or be zero, indicating that nothing is being + * copied in that txg). + */ + if (svr->svr_max_offset_to_sync[txgoff] != 0) { + ASSERT3U(svr->svr_max_offset_to_sync[txgoff], + >=, max_offset_yet); + max_offset_yet = + svr->svr_max_offset_to_sync[txgoff]; + } + + /* + * We've already committed to copying this segment: + * we have allocated space elsewhere in the pool for + * it and have an IO outstanding to copy the data. We + * cannot free the space before the copy has + * completed, or else the copy IO might overwrite any + * new data. To free that space, we record the + * segment in the appropriate svr_frees tree and free + * the mapped space later, in the txg where we have + * completed the copy and synced the mapping (see + * vdev_mapping_sync). + */ + range_tree_add(svr->svr_frees[txgoff], + offset, inflight_size); + size -= inflight_size; + offset += inflight_size; + + /* + * This space is already accounted for as being + * done, because it is being copied in txg+i. + * However, if i!=0, then it is being copied in + * a future txg. If we crash after this txg + * syncs but before txg+i syncs, then the space + * will be free. Therefore we must account + * for the space being done in *this* txg + * (when it is freed) rather than the future txg + * (when it will be copied). + */ + ASSERT3U(svr->svr_bytes_done[txgoff], >=, + inflight_size); + svr->svr_bytes_done[txgoff] -= inflight_size; + svr->svr_bytes_done[txg & TXG_MASK] += inflight_size; + } + } + ASSERT0(svr->svr_max_offset_to_sync[TXG_CLEAN(txg) & TXG_MASK]); + + if (size > 0) { + /* + * The copy thread has not yet visited this offset. Ensure + * that it doesn't. + */ + + DTRACE_PROBE3(remove__free__unvisited, + spa_t *, spa, + uint64_t, offset, + uint64_t, size); + + if (svr->svr_allocd_segs != NULL) + range_tree_clear(svr->svr_allocd_segs, offset, size); + + /* + * Since we now do not need to copy this data, for + * accounting purposes we have done our job and can count + * it as completed. + */ + svr->svr_bytes_done[txg & TXG_MASK] += size; + } + mutex_exit(&svr->svr_lock); + + /* + * Now that we have dropped svr_lock, process the synced portion + * of this free. + */ + if (synced_size > 0) { + vdev_indirect_mark_obsolete(vd, synced_offset, synced_size); + + /* + * Note: this can only be called from syncing context, + * and the vdev_indirect_mapping is only changed from the + * sync thread, so we don't need svr_lock while doing + * metaslab_free_impl_cb. + */ + boolean_t checkpoint = B_FALSE; + vdev_indirect_ops.vdev_op_remap(vd, synced_offset, synced_size, + metaslab_free_impl_cb, &checkpoint); + } +} + +/* + * Stop an active removal and update the spa_removing phys. + */ +static void +spa_finish_removal(spa_t *spa, dsl_scan_state_t state, dmu_tx_t *tx) +{ + spa_vdev_removal_t *svr = spa->spa_vdev_removal; + ASSERT3U(dmu_tx_get_txg(tx), ==, spa_syncing_txg(spa)); + + /* Ensure the removal thread has completed before we free the svr. */ + spa_vdev_remove_suspend(spa); + + ASSERT(state == DSS_FINISHED || state == DSS_CANCELED); + + if (state == DSS_FINISHED) { + spa_removing_phys_t *srp = &spa->spa_removing_phys; + vdev_t *vd = vdev_lookup_top(spa, svr->svr_vdev_id); + vdev_indirect_config_t *vic = &vd->vdev_indirect_config; + + if (srp->sr_prev_indirect_vdev != -1) { + vdev_t *pvd; + pvd = vdev_lookup_top(spa, + srp->sr_prev_indirect_vdev); + ASSERT3P(pvd->vdev_ops, ==, &vdev_indirect_ops); + } + + vic->vic_prev_indirect_vdev = srp->sr_prev_indirect_vdev; + srp->sr_prev_indirect_vdev = vd->vdev_id; + } + spa->spa_removing_phys.sr_state = state; + spa->spa_removing_phys.sr_end_time = gethrestime_sec(); + + spa->spa_vdev_removal = NULL; + spa_vdev_removal_destroy(svr); + + spa_sync_removing_state(spa, tx); + spa_notify_waiters(spa); + + vdev_config_dirty(spa->spa_root_vdev); +} + +static void +free_mapped_segment_cb(void *arg, uint64_t offset, uint64_t size) +{ + vdev_t *vd = arg; + vdev_indirect_mark_obsolete(vd, offset, size); + boolean_t checkpoint = B_FALSE; + vdev_indirect_ops.vdev_op_remap(vd, offset, size, + metaslab_free_impl_cb, &checkpoint); +} + +/* + * On behalf of the removal thread, syncs an incremental bit more of + * the indirect mapping to disk and updates the in-memory mapping. + * Called as a sync task in every txg that the removal thread makes progress. + */ +static void +vdev_mapping_sync(void *arg, dmu_tx_t *tx) +{ + spa_vdev_removal_t *svr = arg; + spa_t *spa = dmu_tx_pool(tx)->dp_spa; + vdev_t *vd = vdev_lookup_top(spa, svr->svr_vdev_id); + vdev_indirect_config_t *vic __maybe_unused = &vd->vdev_indirect_config; + uint64_t txg = dmu_tx_get_txg(tx); + vdev_indirect_mapping_t *vim = vd->vdev_indirect_mapping; + + ASSERT(vic->vic_mapping_object != 0); + ASSERT3U(txg, ==, spa_syncing_txg(spa)); + + vdev_indirect_mapping_add_entries(vim, + &svr->svr_new_segments[txg & TXG_MASK], tx); + vdev_indirect_births_add_entry(vd->vdev_indirect_births, + vdev_indirect_mapping_max_offset(vim), dmu_tx_get_txg(tx), tx); + + /* + * Free the copied data for anything that was freed while the + * mapping entries were in flight. + */ + mutex_enter(&svr->svr_lock); + range_tree_vacate(svr->svr_frees[txg & TXG_MASK], + free_mapped_segment_cb, vd); + ASSERT3U(svr->svr_max_offset_to_sync[txg & TXG_MASK], >=, + vdev_indirect_mapping_max_offset(vim)); + svr->svr_max_offset_to_sync[txg & TXG_MASK] = 0; + mutex_exit(&svr->svr_lock); + + spa_sync_removing_state(spa, tx); +} + +typedef struct vdev_copy_segment_arg { + spa_t *vcsa_spa; + dva_t *vcsa_dest_dva; + uint64_t vcsa_txg; + range_tree_t *vcsa_obsolete_segs; +} vdev_copy_segment_arg_t; + +static void +unalloc_seg(void *arg, uint64_t start, uint64_t size) +{ + vdev_copy_segment_arg_t *vcsa = arg; + spa_t *spa = vcsa->vcsa_spa; + blkptr_t bp = { { { {0} } } }; + + BP_SET_BIRTH(&bp, TXG_INITIAL, TXG_INITIAL); + BP_SET_LSIZE(&bp, size); + BP_SET_PSIZE(&bp, size); + BP_SET_COMPRESS(&bp, ZIO_COMPRESS_OFF); + BP_SET_CHECKSUM(&bp, ZIO_CHECKSUM_OFF); + BP_SET_TYPE(&bp, DMU_OT_NONE); + BP_SET_LEVEL(&bp, 0); + BP_SET_DEDUP(&bp, 0); + BP_SET_BYTEORDER(&bp, ZFS_HOST_BYTEORDER); + + DVA_SET_VDEV(&bp.blk_dva[0], DVA_GET_VDEV(vcsa->vcsa_dest_dva)); + DVA_SET_OFFSET(&bp.blk_dva[0], + DVA_GET_OFFSET(vcsa->vcsa_dest_dva) + start); + DVA_SET_ASIZE(&bp.blk_dva[0], size); + + zio_free(spa, vcsa->vcsa_txg, &bp); +} + +/* + * All reads and writes associated with a call to spa_vdev_copy_segment() + * are done. + */ +static void +spa_vdev_copy_segment_done(zio_t *zio) +{ + vdev_copy_segment_arg_t *vcsa = zio->io_private; + + range_tree_vacate(vcsa->vcsa_obsolete_segs, + unalloc_seg, vcsa); + range_tree_destroy(vcsa->vcsa_obsolete_segs); + kmem_free(vcsa, sizeof (*vcsa)); + + spa_config_exit(zio->io_spa, SCL_STATE, zio->io_spa); +} + +/* + * The write of the new location is done. + */ +static void +spa_vdev_copy_segment_write_done(zio_t *zio) +{ + vdev_copy_arg_t *vca = zio->io_private; + + abd_free(zio->io_abd); + + mutex_enter(&vca->vca_lock); + vca->vca_outstanding_bytes -= zio->io_size; + + if (zio->io_error != 0) + vca->vca_write_error_bytes += zio->io_size; + + cv_signal(&vca->vca_cv); + mutex_exit(&vca->vca_lock); +} + +/* + * The read of the old location is done. The parent zio is the write to + * the new location. Allow it to start. + */ +static void +spa_vdev_copy_segment_read_done(zio_t *zio) +{ + vdev_copy_arg_t *vca = zio->io_private; + + if (zio->io_error != 0) { + mutex_enter(&vca->vca_lock); + vca->vca_read_error_bytes += zio->io_size; + mutex_exit(&vca->vca_lock); + } + + zio_nowait(zio_unique_parent(zio)); +} + +/* + * If the old and new vdevs are mirrors, we will read both sides of the old + * mirror, and write each copy to the corresponding side of the new mirror. + * If the old and new vdevs have a different number of children, we will do + * this as best as possible. Since we aren't verifying checksums, this + * ensures that as long as there's a good copy of the data, we'll have a + * good copy after the removal, even if there's silent damage to one side + * of the mirror. If we're removing a mirror that has some silent damage, + * we'll have exactly the same damage in the new location (assuming that + * the new location is also a mirror). + * + * We accomplish this by creating a tree of zio_t's, with as many writes as + * there are "children" of the new vdev (a non-redundant vdev counts as one + * child, a 2-way mirror has 2 children, etc). Each write has an associated + * read from a child of the old vdev. Typically there will be the same + * number of children of the old and new vdevs. However, if there are more + * children of the new vdev, some child(ren) of the old vdev will be issued + * multiple reads. If there are more children of the old vdev, some copies + * will be dropped. + * + * For example, the tree of zio_t's for a 2-way mirror is: + * + * null + * / \ + * write(new vdev, child 0) write(new vdev, child 1) + * | | + * read(old vdev, child 0) read(old vdev, child 1) + * + * Child zio's complete before their parents complete. However, zio's + * created with zio_vdev_child_io() may be issued before their children + * complete. In this case we need to make sure that the children (reads) + * complete before the parents (writes) are *issued*. We do this by not + * calling zio_nowait() on each write until its corresponding read has + * completed. + * + * The spa_config_lock must be held while zio's created by + * zio_vdev_child_io() are in progress, to ensure that the vdev tree does + * not change (e.g. due to a concurrent "zpool attach/detach"). The "null" + * zio is needed to release the spa_config_lock after all the reads and + * writes complete. (Note that we can't grab the config lock for each read, + * because it is not reentrant - we could deadlock with a thread waiting + * for a write lock.) + */ +static void +spa_vdev_copy_one_child(vdev_copy_arg_t *vca, zio_t *nzio, + vdev_t *source_vd, uint64_t source_offset, + vdev_t *dest_child_vd, uint64_t dest_offset, int dest_id, uint64_t size) +{ + ASSERT3U(spa_config_held(nzio->io_spa, SCL_ALL, RW_READER), !=, 0); + + /* + * If the destination child in unwritable then there is no point + * in issuing the source reads which cannot be written. + */ + if (!vdev_writeable(dest_child_vd)) + return; + + mutex_enter(&vca->vca_lock); + vca->vca_outstanding_bytes += size; + mutex_exit(&vca->vca_lock); + + abd_t *abd = abd_alloc_for_io(size, B_FALSE); + + vdev_t *source_child_vd = NULL; + if (source_vd->vdev_ops == &vdev_mirror_ops && dest_id != -1) { + /* + * Source and dest are both mirrors. Copy from the same + * child id as we are copying to (wrapping around if there + * are more dest children than source children). If the + * preferred source child is unreadable select another. + */ + for (int i = 0; i < source_vd->vdev_children; i++) { + source_child_vd = source_vd->vdev_child[ + (dest_id + i) % source_vd->vdev_children]; + if (vdev_readable(source_child_vd)) + break; + } + } else { + source_child_vd = source_vd; + } + + /* + * There should always be at least one readable source child or + * the pool would be in a suspended state. Somehow selecting an + * unreadable child would result in IO errors, the removal process + * being cancelled, and the pool reverting to its pre-removal state. + */ + ASSERT3P(source_child_vd, !=, NULL); + + zio_t *write_zio = zio_vdev_child_io(nzio, NULL, + dest_child_vd, dest_offset, abd, size, + ZIO_TYPE_WRITE, ZIO_PRIORITY_REMOVAL, + ZIO_FLAG_CANFAIL, + spa_vdev_copy_segment_write_done, vca); + + zio_nowait(zio_vdev_child_io(write_zio, NULL, + source_child_vd, source_offset, abd, size, + ZIO_TYPE_READ, ZIO_PRIORITY_REMOVAL, + ZIO_FLAG_CANFAIL, + spa_vdev_copy_segment_read_done, vca)); +} + +/* + * Allocate a new location for this segment, and create the zio_t's to + * read from the old location and write to the new location. + */ +static int +spa_vdev_copy_segment(vdev_t *vd, range_tree_t *segs, + uint64_t maxalloc, uint64_t txg, + vdev_copy_arg_t *vca, zio_alloc_list_t *zal) +{ + metaslab_group_t *mg = vd->vdev_mg; + spa_t *spa = vd->vdev_spa; + spa_vdev_removal_t *svr = spa->spa_vdev_removal; + vdev_indirect_mapping_entry_t *entry; + dva_t dst = {{ 0 }}; + uint64_t start = range_tree_min(segs); + ASSERT0(P2PHASE(start, 1 << spa->spa_min_ashift)); + + ASSERT3U(maxalloc, <=, SPA_MAXBLOCKSIZE); + ASSERT0(P2PHASE(maxalloc, 1 << spa->spa_min_ashift)); + + uint64_t size = range_tree_span(segs); + if (range_tree_span(segs) > maxalloc) { + /* + * We can't allocate all the segments. Prefer to end + * the allocation at the end of a segment, thus avoiding + * additional split blocks. + */ + range_seg_max_t search; + zfs_btree_index_t where; + rs_set_start(&search, segs, start + maxalloc); + rs_set_end(&search, segs, start + maxalloc); + (void) zfs_btree_find(&segs->rt_root, &search, &where); + range_seg_t *rs = zfs_btree_prev(&segs->rt_root, &where, + &where); + if (rs != NULL) { + size = rs_get_end(rs, segs) - start; + } else { + /* + * There are no segments that end before maxalloc. + * I.e. the first segment is larger than maxalloc, + * so we must split it. + */ + size = maxalloc; + } + } + ASSERT3U(size, <=, maxalloc); + ASSERT0(P2PHASE(size, 1 << spa->spa_min_ashift)); + + /* + * An allocation class might not have any remaining vdevs or space + */ + metaslab_class_t *mc = mg->mg_class; + if (mc != spa_normal_class(spa) && mc->mc_groups <= 1) + mc = spa_normal_class(spa); + int error = metaslab_alloc_dva(spa, mc, size, &dst, 0, NULL, txg, 0, + zal, 0); + if (error == ENOSPC && mc != spa_normal_class(spa)) { + error = metaslab_alloc_dva(spa, spa_normal_class(spa), size, + &dst, 0, NULL, txg, 0, zal, 0); + } + if (error != 0) + return (error); + + /* + * Determine the ranges that are not actually needed. Offsets are + * relative to the start of the range to be copied (i.e. relative to the + * local variable "start"). + */ + range_tree_t *obsolete_segs = range_tree_create(NULL, RANGE_SEG64, NULL, + 0, 0); + + zfs_btree_index_t where; + range_seg_t *rs = zfs_btree_first(&segs->rt_root, &where); + ASSERT3U(rs_get_start(rs, segs), ==, start); + uint64_t prev_seg_end = rs_get_end(rs, segs); + while ((rs = zfs_btree_next(&segs->rt_root, &where, &where)) != NULL) { + if (rs_get_start(rs, segs) >= start + size) { + break; + } else { + range_tree_add(obsolete_segs, + prev_seg_end - start, + rs_get_start(rs, segs) - prev_seg_end); + } + prev_seg_end = rs_get_end(rs, segs); + } + /* We don't end in the middle of an obsolete range */ + ASSERT3U(start + size, <=, prev_seg_end); + + range_tree_clear(segs, start, size); + + /* + * We can't have any padding of the allocated size, otherwise we will + * misunderstand what's allocated, and the size of the mapping. We + * prevent padding by ensuring that all devices in the pool have the + * same ashift, and the allocation size is a multiple of the ashift. + */ + VERIFY3U(DVA_GET_ASIZE(&dst), ==, size); + + entry = kmem_zalloc(sizeof (vdev_indirect_mapping_entry_t), KM_SLEEP); + DVA_MAPPING_SET_SRC_OFFSET(&entry->vime_mapping, start); + entry->vime_mapping.vimep_dst = dst; + if (spa_feature_is_enabled(spa, SPA_FEATURE_OBSOLETE_COUNTS)) { + entry->vime_obsolete_count = range_tree_space(obsolete_segs); + } + + vdev_copy_segment_arg_t *vcsa = kmem_zalloc(sizeof (*vcsa), KM_SLEEP); + vcsa->vcsa_dest_dva = &entry->vime_mapping.vimep_dst; + vcsa->vcsa_obsolete_segs = obsolete_segs; + vcsa->vcsa_spa = spa; + vcsa->vcsa_txg = txg; + + /* + * See comment before spa_vdev_copy_one_child(). + */ + spa_config_enter(spa, SCL_STATE, spa, RW_READER); + zio_t *nzio = zio_null(spa->spa_txg_zio[txg & TXG_MASK], spa, NULL, + spa_vdev_copy_segment_done, vcsa, 0); + vdev_t *dest_vd = vdev_lookup_top(spa, DVA_GET_VDEV(&dst)); + if (dest_vd->vdev_ops == &vdev_mirror_ops) { + for (int i = 0; i < dest_vd->vdev_children; i++) { + vdev_t *child = dest_vd->vdev_child[i]; + spa_vdev_copy_one_child(vca, nzio, vd, start, + child, DVA_GET_OFFSET(&dst), i, size); + } + } else { + spa_vdev_copy_one_child(vca, nzio, vd, start, + dest_vd, DVA_GET_OFFSET(&dst), -1, size); + } + zio_nowait(nzio); + + list_insert_tail(&svr->svr_new_segments[txg & TXG_MASK], entry); + ASSERT3U(start + size, <=, vd->vdev_ms_count << vd->vdev_ms_shift); + vdev_dirty(vd, 0, NULL, txg); + + return (0); +} + +/* + * Complete the removal of a toplevel vdev. This is called as a + * synctask in the same txg that we will sync out the new config (to the + * MOS object) which indicates that this vdev is indirect. + */ +static void +vdev_remove_complete_sync(void *arg, dmu_tx_t *tx) +{ + spa_vdev_removal_t *svr = arg; + spa_t *spa = dmu_tx_pool(tx)->dp_spa; + vdev_t *vd = vdev_lookup_top(spa, svr->svr_vdev_id); + + ASSERT3P(vd->vdev_ops, ==, &vdev_indirect_ops); + + for (int i = 0; i < TXG_SIZE; i++) { + ASSERT0(svr->svr_bytes_done[i]); + } + + ASSERT3U(spa->spa_removing_phys.sr_copied, ==, + spa->spa_removing_phys.sr_to_copy); + + vdev_destroy_spacemaps(vd, tx); + + /* destroy leaf zaps, if any */ + ASSERT3P(svr->svr_zaplist, !=, NULL); + for (nvpair_t *pair = nvlist_next_nvpair(svr->svr_zaplist, NULL); + pair != NULL; + pair = nvlist_next_nvpair(svr->svr_zaplist, pair)) { + vdev_destroy_unlink_zap(vd, fnvpair_value_uint64(pair), tx); + } + fnvlist_free(svr->svr_zaplist); + + spa_finish_removal(dmu_tx_pool(tx)->dp_spa, DSS_FINISHED, tx); + /* vd->vdev_path is not available here */ + spa_history_log_internal(spa, "vdev remove completed", tx, + "%s vdev %llu", spa_name(spa), (u_longlong_t)vd->vdev_id); +} + +static void +vdev_remove_enlist_zaps(vdev_t *vd, nvlist_t *zlist) +{ + ASSERT3P(zlist, !=, NULL); + ASSERT3P(vd->vdev_ops, !=, &vdev_raidz_ops); + + if (vd->vdev_leaf_zap != 0) { + char zkey[32]; + (void) snprintf(zkey, sizeof (zkey), "%s-%llu", + VDEV_REMOVAL_ZAP_OBJS, (u_longlong_t)vd->vdev_leaf_zap); + fnvlist_add_uint64(zlist, zkey, vd->vdev_leaf_zap); + } + + for (uint64_t id = 0; id < vd->vdev_children; id++) { + vdev_remove_enlist_zaps(vd->vdev_child[id], zlist); + } +} + +static void +vdev_remove_replace_with_indirect(vdev_t *vd, uint64_t txg) +{ + vdev_t *ivd; + dmu_tx_t *tx; + spa_t *spa = vd->vdev_spa; + spa_vdev_removal_t *svr = spa->spa_vdev_removal; + + /* + * First, build a list of leaf zaps to be destroyed. + * This is passed to the sync context thread, + * which does the actual unlinking. + */ + svr->svr_zaplist = fnvlist_alloc(); + vdev_remove_enlist_zaps(vd, svr->svr_zaplist); + + ivd = vdev_add_parent(vd, &vdev_indirect_ops); + ivd->vdev_removing = 0; + + vd->vdev_leaf_zap = 0; + + vdev_remove_child(ivd, vd); + vdev_compact_children(ivd); + + ASSERT(!list_link_active(&vd->vdev_state_dirty_node)); + + mutex_enter(&svr->svr_lock); + svr->svr_thread = NULL; + cv_broadcast(&svr->svr_cv); + mutex_exit(&svr->svr_lock); + + /* After this, we can not use svr. */ + tx = dmu_tx_create_assigned(spa->spa_dsl_pool, txg); + dsl_sync_task_nowait(spa->spa_dsl_pool, vdev_remove_complete_sync, svr, + 0, ZFS_SPACE_CHECK_NONE, tx); + dmu_tx_commit(tx); +} + +/* + * Complete the removal of a toplevel vdev. This is called in open + * context by the removal thread after we have copied all vdev's data. + */ +static void +vdev_remove_complete(spa_t *spa) +{ + uint64_t txg; + + /* + * Wait for any deferred frees to be synced before we call + * vdev_metaslab_fini() + */ + txg_wait_synced(spa->spa_dsl_pool, 0); + txg = spa_vdev_enter(spa); + vdev_t *vd = vdev_lookup_top(spa, spa->spa_vdev_removal->svr_vdev_id); + ASSERT3P(vd->vdev_initialize_thread, ==, NULL); + ASSERT3P(vd->vdev_trim_thread, ==, NULL); + ASSERT3P(vd->vdev_autotrim_thread, ==, NULL); + + sysevent_t *ev = spa_event_create(spa, vd, NULL, + ESC_ZFS_VDEV_REMOVE_DEV); + + zfs_dbgmsg("finishing device removal for vdev %llu in txg %llu", + vd->vdev_id, txg); + + /* + * Discard allocation state. + */ + if (vd->vdev_mg != NULL) { + vdev_metaslab_fini(vd); + metaslab_group_destroy(vd->vdev_mg); + vd->vdev_mg = NULL; + spa_log_sm_set_blocklimit(spa); + } + ASSERT0(vd->vdev_stat.vs_space); + ASSERT0(vd->vdev_stat.vs_dspace); + + vdev_remove_replace_with_indirect(vd, txg); + + /* + * We now release the locks, allowing spa_sync to run and finish the + * removal via vdev_remove_complete_sync in syncing context. + * + * Note that we hold on to the vdev_t that has been replaced. Since + * it isn't part of the vdev tree any longer, it can't be concurrently + * manipulated, even while we don't have the config lock. + */ + (void) spa_vdev_exit(spa, NULL, txg, 0); + + /* + * Top ZAP should have been transferred to the indirect vdev in + * vdev_remove_replace_with_indirect. + */ + ASSERT0(vd->vdev_top_zap); + + /* + * Leaf ZAP should have been moved in vdev_remove_replace_with_indirect. + */ + ASSERT0(vd->vdev_leaf_zap); + + txg = spa_vdev_enter(spa); + (void) vdev_label_init(vd, 0, VDEV_LABEL_REMOVE); + /* + * Request to update the config and the config cachefile. + */ + vdev_config_dirty(spa->spa_root_vdev); + (void) spa_vdev_exit(spa, vd, txg, 0); + + if (ev != NULL) + spa_event_post(ev); +} + +/* + * Evacuates a segment of size at most max_alloc from the vdev + * via repeated calls to spa_vdev_copy_segment. If an allocation + * fails, the pool is probably too fragmented to handle such a + * large size, so decrease max_alloc so that the caller will not try + * this size again this txg. + */ +static void +spa_vdev_copy_impl(vdev_t *vd, spa_vdev_removal_t *svr, vdev_copy_arg_t *vca, + uint64_t *max_alloc, dmu_tx_t *tx) +{ + uint64_t txg = dmu_tx_get_txg(tx); + spa_t *spa = dmu_tx_pool(tx)->dp_spa; + + mutex_enter(&svr->svr_lock); + + /* + * Determine how big of a chunk to copy. We can allocate up + * to max_alloc bytes, and we can span up to vdev_removal_max_span + * bytes of unallocated space at a time. "segs" will track the + * allocated segments that we are copying. We may also be copying + * free segments (of up to vdev_removal_max_span bytes). + */ + range_tree_t *segs = range_tree_create(NULL, RANGE_SEG64, NULL, 0, 0); + for (;;) { + range_tree_t *rt = svr->svr_allocd_segs; + range_seg_t *rs = range_tree_first(rt); + + if (rs == NULL) + break; + + uint64_t seg_length; + + if (range_tree_is_empty(segs)) { + /* need to truncate the first seg based on max_alloc */ + seg_length = MIN(rs_get_end(rs, rt) - rs_get_start(rs, + rt), *max_alloc); + } else { + if (rs_get_start(rs, rt) - range_tree_max(segs) > + vdev_removal_max_span) { + /* + * Including this segment would cause us to + * copy a larger unneeded chunk than is allowed. + */ + break; + } else if (rs_get_end(rs, rt) - range_tree_min(segs) > + *max_alloc) { + /* + * This additional segment would extend past + * max_alloc. Rather than splitting this + * segment, leave it for the next mapping. + */ + break; + } else { + seg_length = rs_get_end(rs, rt) - + rs_get_start(rs, rt); + } + } + + range_tree_add(segs, rs_get_start(rs, rt), seg_length); + range_tree_remove(svr->svr_allocd_segs, + rs_get_start(rs, rt), seg_length); + } + + if (range_tree_is_empty(segs)) { + mutex_exit(&svr->svr_lock); + range_tree_destroy(segs); + return; + } + + if (svr->svr_max_offset_to_sync[txg & TXG_MASK] == 0) { + dsl_sync_task_nowait(dmu_tx_pool(tx), vdev_mapping_sync, + svr, 0, ZFS_SPACE_CHECK_NONE, tx); + } + + svr->svr_max_offset_to_sync[txg & TXG_MASK] = range_tree_max(segs); + + /* + * Note: this is the amount of *allocated* space + * that we are taking care of each txg. + */ + svr->svr_bytes_done[txg & TXG_MASK] += range_tree_space(segs); + + mutex_exit(&svr->svr_lock); + + zio_alloc_list_t zal; + metaslab_trace_init(&zal); + uint64_t thismax = SPA_MAXBLOCKSIZE; + while (!range_tree_is_empty(segs)) { + int error = spa_vdev_copy_segment(vd, + segs, thismax, txg, vca, &zal); + + if (error == ENOSPC) { + /* + * Cut our segment in half, and don't try this + * segment size again this txg. Note that the + * allocation size must be aligned to the highest + * ashift in the pool, so that the allocation will + * not be padded out to a multiple of the ashift, + * which could cause us to think that this mapping + * is larger than we intended. + */ + ASSERT3U(spa->spa_max_ashift, >=, SPA_MINBLOCKSHIFT); + ASSERT3U(spa->spa_max_ashift, ==, spa->spa_min_ashift); + uint64_t attempted = + MIN(range_tree_span(segs), thismax); + thismax = P2ROUNDUP(attempted / 2, + 1 << spa->spa_max_ashift); + /* + * The minimum-size allocation can not fail. + */ + ASSERT3U(attempted, >, 1 << spa->spa_max_ashift); + *max_alloc = attempted - (1 << spa->spa_max_ashift); + } else { + ASSERT0(error); + + /* + * We've performed an allocation, so reset the + * alloc trace list. + */ + metaslab_trace_fini(&zal); + metaslab_trace_init(&zal); + } + } + metaslab_trace_fini(&zal); + range_tree_destroy(segs); +} + +/* + * The size of each removal mapping is limited by the tunable + * zfs_remove_max_segment, but we must adjust this to be a multiple of the + * pool's ashift, so that we don't try to split individual sectors regardless + * of the tunable value. (Note that device removal requires that all devices + * have the same ashift, so there's no difference between spa_min_ashift and + * spa_max_ashift.) The raw tunable should not be used elsewhere. + */ +uint64_t +spa_remove_max_segment(spa_t *spa) +{ + return (P2ROUNDUP(zfs_remove_max_segment, 1 << spa->spa_max_ashift)); +} + +/* + * The removal thread operates in open context. It iterates over all + * allocated space in the vdev, by loading each metaslab's spacemap. + * For each contiguous segment of allocated space (capping the segment + * size at SPA_MAXBLOCKSIZE), we: + * - Allocate space for it on another vdev. + * - Create a new mapping from the old location to the new location + * (as a record in svr_new_segments). + * - Initiate a physical read zio to get the data off the removing disk. + * - In the read zio's done callback, initiate a physical write zio to + * write it to the new vdev. + * Note that all of this will take effect when a particular TXG syncs. + * The sync thread ensures that all the phys reads and writes for the syncing + * TXG have completed (see spa_txg_zio) and writes the new mappings to disk + * (see vdev_mapping_sync()). + */ +static void +spa_vdev_remove_thread(void *arg) +{ + spa_t *spa = arg; + spa_vdev_removal_t *svr = spa->spa_vdev_removal; + vdev_copy_arg_t vca; + uint64_t max_alloc = spa_remove_max_segment(spa); + uint64_t last_txg = 0; + + spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER); + vdev_t *vd = vdev_lookup_top(spa, svr->svr_vdev_id); + vdev_indirect_mapping_t *vim = vd->vdev_indirect_mapping; + uint64_t start_offset = vdev_indirect_mapping_max_offset(vim); + + ASSERT3P(vd->vdev_ops, !=, &vdev_indirect_ops); + ASSERT(vdev_is_concrete(vd)); + ASSERT(vd->vdev_removing); + ASSERT(vd->vdev_indirect_config.vic_mapping_object != 0); + ASSERT(vim != NULL); + + mutex_init(&vca.vca_lock, NULL, MUTEX_DEFAULT, NULL); + cv_init(&vca.vca_cv, NULL, CV_DEFAULT, NULL); + vca.vca_outstanding_bytes = 0; + vca.vca_read_error_bytes = 0; + vca.vca_write_error_bytes = 0; + + mutex_enter(&svr->svr_lock); + + /* + * Start from vim_max_offset so we pick up where we left off + * if we are restarting the removal after opening the pool. + */ + uint64_t msi; + for (msi = start_offset >> vd->vdev_ms_shift; + msi < vd->vdev_ms_count && !svr->svr_thread_exit; msi++) { + metaslab_t *msp = vd->vdev_ms[msi]; + ASSERT3U(msi, <=, vd->vdev_ms_count); + + ASSERT0(range_tree_space(svr->svr_allocd_segs)); + + mutex_enter(&msp->ms_sync_lock); + mutex_enter(&msp->ms_lock); + + /* + * Assert nothing in flight -- ms_*tree is empty. + */ + for (int i = 0; i < TXG_SIZE; i++) { + ASSERT0(range_tree_space(msp->ms_allocating[i])); + } + + /* + * If the metaslab has ever been allocated from (ms_sm!=NULL), + * read the allocated segments from the space map object + * into svr_allocd_segs. Since we do this while holding + * svr_lock and ms_sync_lock, concurrent frees (which + * would have modified the space map) will wait for us + * to finish loading the spacemap, and then take the + * appropriate action (see free_from_removing_vdev()). + */ + if (msp->ms_sm != NULL) { + VERIFY0(space_map_load(msp->ms_sm, + svr->svr_allocd_segs, SM_ALLOC)); + + range_tree_walk(msp->ms_unflushed_allocs, + range_tree_add, svr->svr_allocd_segs); + range_tree_walk(msp->ms_unflushed_frees, + range_tree_remove, svr->svr_allocd_segs); + range_tree_walk(msp->ms_freeing, + range_tree_remove, svr->svr_allocd_segs); + + /* + * When we are resuming from a paused removal (i.e. + * when importing a pool with a removal in progress), + * discard any state that we have already processed. + */ + range_tree_clear(svr->svr_allocd_segs, 0, start_offset); + } + mutex_exit(&msp->ms_lock); + mutex_exit(&msp->ms_sync_lock); + + vca.vca_msp = msp; + zfs_dbgmsg("copying %llu segments for metaslab %llu", + zfs_btree_numnodes(&svr->svr_allocd_segs->rt_root), + msp->ms_id); + + while (!svr->svr_thread_exit && + !range_tree_is_empty(svr->svr_allocd_segs)) { + + mutex_exit(&svr->svr_lock); + + /* + * We need to periodically drop the config lock so that + * writers can get in. Additionally, we can't wait + * for a txg to sync while holding a config lock + * (since a waiting writer could cause a 3-way deadlock + * with the sync thread, which also gets a config + * lock for reader). So we can't hold the config lock + * while calling dmu_tx_assign(). + */ + spa_config_exit(spa, SCL_CONFIG, FTAG); + + /* + * This delay will pause the removal around the point + * specified by zfs_removal_suspend_progress. We do this + * solely from the test suite or during debugging. + */ + uint64_t bytes_copied = + spa->spa_removing_phys.sr_copied; + for (int i = 0; i < TXG_SIZE; i++) + bytes_copied += svr->svr_bytes_done[i]; + while (zfs_removal_suspend_progress && + !svr->svr_thread_exit) + delay(hz); + + mutex_enter(&vca.vca_lock); + while (vca.vca_outstanding_bytes > + zfs_remove_max_copy_bytes) { + cv_wait(&vca.vca_cv, &vca.vca_lock); + } + mutex_exit(&vca.vca_lock); + + dmu_tx_t *tx = + dmu_tx_create_dd(spa_get_dsl(spa)->dp_mos_dir); + + VERIFY0(dmu_tx_assign(tx, TXG_WAIT)); + uint64_t txg = dmu_tx_get_txg(tx); + + /* + * Reacquire the vdev_config lock. The vdev_t + * that we're removing may have changed, e.g. due + * to a vdev_attach or vdev_detach. + */ + spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER); + vd = vdev_lookup_top(spa, svr->svr_vdev_id); + + if (txg != last_txg) + max_alloc = spa_remove_max_segment(spa); + last_txg = txg; + + spa_vdev_copy_impl(vd, svr, &vca, &max_alloc, tx); + + dmu_tx_commit(tx); + mutex_enter(&svr->svr_lock); + } + + mutex_enter(&vca.vca_lock); + if (zfs_removal_ignore_errors == 0 && + (vca.vca_read_error_bytes > 0 || + vca.vca_write_error_bytes > 0)) { + svr->svr_thread_exit = B_TRUE; + } + mutex_exit(&vca.vca_lock); + } + + mutex_exit(&svr->svr_lock); + + spa_config_exit(spa, SCL_CONFIG, FTAG); + + /* + * Wait for all copies to finish before cleaning up the vca. + */ + txg_wait_synced(spa->spa_dsl_pool, 0); + ASSERT0(vca.vca_outstanding_bytes); + + mutex_destroy(&vca.vca_lock); + cv_destroy(&vca.vca_cv); + + if (svr->svr_thread_exit) { + mutex_enter(&svr->svr_lock); + range_tree_vacate(svr->svr_allocd_segs, NULL, NULL); + svr->svr_thread = NULL; + cv_broadcast(&svr->svr_cv); + mutex_exit(&svr->svr_lock); + + /* + * During the removal process an unrecoverable read or write + * error was encountered. The removal process must be + * cancelled or this damage may become permanent. + */ + if (zfs_removal_ignore_errors == 0 && + (vca.vca_read_error_bytes > 0 || + vca.vca_write_error_bytes > 0)) { + zfs_dbgmsg("canceling removal due to IO errors: " + "[read_error_bytes=%llu] [write_error_bytes=%llu]", + vca.vca_read_error_bytes, + vca.vca_write_error_bytes); + spa_vdev_remove_cancel_impl(spa); + } + } else { + ASSERT0(range_tree_space(svr->svr_allocd_segs)); + vdev_remove_complete(spa); + } + + thread_exit(); +} + +void +spa_vdev_remove_suspend(spa_t *spa) +{ + spa_vdev_removal_t *svr = spa->spa_vdev_removal; + + if (svr == NULL) + return; + + mutex_enter(&svr->svr_lock); + svr->svr_thread_exit = B_TRUE; + while (svr->svr_thread != NULL) + cv_wait(&svr->svr_cv, &svr->svr_lock); + svr->svr_thread_exit = B_FALSE; + mutex_exit(&svr->svr_lock); +} + +/* ARGSUSED */ +static int +spa_vdev_remove_cancel_check(void *arg, dmu_tx_t *tx) +{ + spa_t *spa = dmu_tx_pool(tx)->dp_spa; + + if (spa->spa_vdev_removal == NULL) + return (ENOTACTIVE); + return (0); +} + +/* + * Cancel a removal by freeing all entries from the partial mapping + * and marking the vdev as no longer being removing. + */ +/* ARGSUSED */ +static void +spa_vdev_remove_cancel_sync(void *arg, dmu_tx_t *tx) +{ + spa_t *spa = dmu_tx_pool(tx)->dp_spa; + spa_vdev_removal_t *svr = spa->spa_vdev_removal; + vdev_t *vd = vdev_lookup_top(spa, svr->svr_vdev_id); + vdev_indirect_config_t *vic = &vd->vdev_indirect_config; + vdev_indirect_mapping_t *vim = vd->vdev_indirect_mapping; + objset_t *mos = spa->spa_meta_objset; + + ASSERT3P(svr->svr_thread, ==, NULL); + + spa_feature_decr(spa, SPA_FEATURE_DEVICE_REMOVAL, tx); + + boolean_t are_precise; + VERIFY0(vdev_obsolete_counts_are_precise(vd, &are_precise)); + if (are_precise) { + spa_feature_decr(spa, SPA_FEATURE_OBSOLETE_COUNTS, tx); + VERIFY0(zap_remove(spa->spa_meta_objset, vd->vdev_top_zap, + VDEV_TOP_ZAP_OBSOLETE_COUNTS_ARE_PRECISE, tx)); + } + + uint64_t obsolete_sm_object; + VERIFY0(vdev_obsolete_sm_object(vd, &obsolete_sm_object)); + if (obsolete_sm_object != 0) { + ASSERT(vd->vdev_obsolete_sm != NULL); + ASSERT3U(obsolete_sm_object, ==, + space_map_object(vd->vdev_obsolete_sm)); + + space_map_free(vd->vdev_obsolete_sm, tx); + VERIFY0(zap_remove(spa->spa_meta_objset, vd->vdev_top_zap, + VDEV_TOP_ZAP_INDIRECT_OBSOLETE_SM, tx)); + space_map_close(vd->vdev_obsolete_sm); + vd->vdev_obsolete_sm = NULL; + spa_feature_decr(spa, SPA_FEATURE_OBSOLETE_COUNTS, tx); + } + for (int i = 0; i < TXG_SIZE; i++) { + ASSERT(list_is_empty(&svr->svr_new_segments[i])); + ASSERT3U(svr->svr_max_offset_to_sync[i], <=, + vdev_indirect_mapping_max_offset(vim)); + } + + for (uint64_t msi = 0; msi < vd->vdev_ms_count; msi++) { + metaslab_t *msp = vd->vdev_ms[msi]; + + if (msp->ms_start >= vdev_indirect_mapping_max_offset(vim)) + break; + + ASSERT0(range_tree_space(svr->svr_allocd_segs)); + + mutex_enter(&msp->ms_lock); + + /* + * Assert nothing in flight -- ms_*tree is empty. + */ + for (int i = 0; i < TXG_SIZE; i++) + ASSERT0(range_tree_space(msp->ms_allocating[i])); + for (int i = 0; i < TXG_DEFER_SIZE; i++) + ASSERT0(range_tree_space(msp->ms_defer[i])); + ASSERT0(range_tree_space(msp->ms_freed)); + + if (msp->ms_sm != NULL) { + mutex_enter(&svr->svr_lock); + VERIFY0(space_map_load(msp->ms_sm, + svr->svr_allocd_segs, SM_ALLOC)); + + range_tree_walk(msp->ms_unflushed_allocs, + range_tree_add, svr->svr_allocd_segs); + range_tree_walk(msp->ms_unflushed_frees, + range_tree_remove, svr->svr_allocd_segs); + range_tree_walk(msp->ms_freeing, + range_tree_remove, svr->svr_allocd_segs); + + /* + * Clear everything past what has been synced, + * because we have not allocated mappings for it yet. + */ + uint64_t syncd = vdev_indirect_mapping_max_offset(vim); + uint64_t sm_end = msp->ms_sm->sm_start + + msp->ms_sm->sm_size; + if (sm_end > syncd) + range_tree_clear(svr->svr_allocd_segs, + syncd, sm_end - syncd); + + mutex_exit(&svr->svr_lock); + } + mutex_exit(&msp->ms_lock); + + mutex_enter(&svr->svr_lock); + range_tree_vacate(svr->svr_allocd_segs, + free_mapped_segment_cb, vd); + mutex_exit(&svr->svr_lock); + } + + /* + * Note: this must happen after we invoke free_mapped_segment_cb, + * because it adds to the obsolete_segments. + */ + range_tree_vacate(vd->vdev_obsolete_segments, NULL, NULL); + + ASSERT3U(vic->vic_mapping_object, ==, + vdev_indirect_mapping_object(vd->vdev_indirect_mapping)); + vdev_indirect_mapping_close(vd->vdev_indirect_mapping); + vd->vdev_indirect_mapping = NULL; + vdev_indirect_mapping_free(mos, vic->vic_mapping_object, tx); + vic->vic_mapping_object = 0; + + ASSERT3U(vic->vic_births_object, ==, + vdev_indirect_births_object(vd->vdev_indirect_births)); + vdev_indirect_births_close(vd->vdev_indirect_births); + vd->vdev_indirect_births = NULL; + vdev_indirect_births_free(mos, vic->vic_births_object, tx); + vic->vic_births_object = 0; + + /* + * We may have processed some frees from the removing vdev in this + * txg, thus increasing svr_bytes_done; discard that here to + * satisfy the assertions in spa_vdev_removal_destroy(). + * Note that future txg's can not have any bytes_done, because + * future TXG's are only modified from open context, and we have + * already shut down the copying thread. + */ + svr->svr_bytes_done[dmu_tx_get_txg(tx) & TXG_MASK] = 0; + spa_finish_removal(spa, DSS_CANCELED, tx); + + vd->vdev_removing = B_FALSE; + vdev_config_dirty(vd); + + zfs_dbgmsg("canceled device removal for vdev %llu in %llu", + vd->vdev_id, dmu_tx_get_txg(tx)); + spa_history_log_internal(spa, "vdev remove canceled", tx, + "%s vdev %llu %s", spa_name(spa), + (u_longlong_t)vd->vdev_id, + (vd->vdev_path != NULL) ? vd->vdev_path : "-"); +} + +static int +spa_vdev_remove_cancel_impl(spa_t *spa) +{ + uint64_t vdid = spa->spa_vdev_removal->svr_vdev_id; + + int error = dsl_sync_task(spa->spa_name, spa_vdev_remove_cancel_check, + spa_vdev_remove_cancel_sync, NULL, 0, + ZFS_SPACE_CHECK_EXTRA_RESERVED); + + if (error == 0) { + spa_config_enter(spa, SCL_ALLOC | SCL_VDEV, FTAG, RW_WRITER); + vdev_t *vd = vdev_lookup_top(spa, vdid); + metaslab_group_activate(vd->vdev_mg); + spa_config_exit(spa, SCL_ALLOC | SCL_VDEV, FTAG); + } + + return (error); +} + +int +spa_vdev_remove_cancel(spa_t *spa) +{ + spa_vdev_remove_suspend(spa); + + if (spa->spa_vdev_removal == NULL) + return (ENOTACTIVE); + + return (spa_vdev_remove_cancel_impl(spa)); +} + +void +svr_sync(spa_t *spa, dmu_tx_t *tx) +{ + spa_vdev_removal_t *svr = spa->spa_vdev_removal; + int txgoff = dmu_tx_get_txg(tx) & TXG_MASK; + + if (svr == NULL) + return; + + /* + * This check is necessary so that we do not dirty the + * DIRECTORY_OBJECT via spa_sync_removing_state() when there + * is nothing to do. Dirtying it every time would prevent us + * from syncing-to-convergence. + */ + if (svr->svr_bytes_done[txgoff] == 0) + return; + + /* + * Update progress accounting. + */ + spa->spa_removing_phys.sr_copied += svr->svr_bytes_done[txgoff]; + svr->svr_bytes_done[txgoff] = 0; + + spa_sync_removing_state(spa, tx); +} + +static void +vdev_remove_make_hole_and_free(vdev_t *vd) +{ + uint64_t id = vd->vdev_id; + spa_t *spa = vd->vdev_spa; + vdev_t *rvd = spa->spa_root_vdev; + + ASSERT(MUTEX_HELD(&spa_namespace_lock)); + ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL); + + vdev_free(vd); + + vd = vdev_alloc_common(spa, id, 0, &vdev_hole_ops); + vdev_add_child(rvd, vd); + vdev_config_dirty(rvd); + + /* + * Reassess the health of our root vdev. + */ + vdev_reopen(rvd); +} + +/* + * Remove a log device. The config lock is held for the specified TXG. + */ +static int +spa_vdev_remove_log(vdev_t *vd, uint64_t *txg) +{ + metaslab_group_t *mg = vd->vdev_mg; + spa_t *spa = vd->vdev_spa; + int error = 0; + + ASSERT(vd->vdev_islog); + ASSERT(vd == vd->vdev_top); + ASSERT(MUTEX_HELD(&spa_namespace_lock)); + + /* + * Stop allocating from this vdev. + */ + metaslab_group_passivate(mg); + + /* + * Wait for the youngest allocations and frees to sync, + * and then wait for the deferral of those frees to finish. + */ + spa_vdev_config_exit(spa, NULL, + *txg + TXG_CONCURRENT_STATES + TXG_DEFER_SIZE, 0, FTAG); + + /* + * Cancel any initialize or TRIM which was in progress. + */ + vdev_initialize_stop_all(vd, VDEV_INITIALIZE_CANCELED); + vdev_trim_stop_all(vd, VDEV_TRIM_CANCELED); + vdev_autotrim_stop_wait(vd); + + /* + * Evacuate the device. We don't hold the config lock as + * writer since we need to do I/O but we do keep the + * spa_namespace_lock held. Once this completes the device + * should no longer have any blocks allocated on it. + */ + ASSERT(MUTEX_HELD(&spa_namespace_lock)); + if (vd->vdev_stat.vs_alloc != 0) + error = spa_reset_logs(spa); + + *txg = spa_vdev_config_enter(spa); + + if (error != 0) { + metaslab_group_activate(mg); + return (error); + } + ASSERT0(vd->vdev_stat.vs_alloc); + + /* + * The evacuation succeeded. Remove any remaining MOS metadata + * associated with this vdev, and wait for these changes to sync. + */ + vd->vdev_removing = B_TRUE; + + vdev_dirty_leaves(vd, VDD_DTL, *txg); + vdev_config_dirty(vd); + + /* + * When the log space map feature is enabled we look at + * the vdev's top_zap to find the on-disk flush data of + * the metaslab we just flushed. Thus, while removing a + * log vdev we make sure to call vdev_metaslab_fini() + * first, which removes all metaslabs of this vdev from + * spa_metaslabs_by_flushed before vdev_remove_empty() + * destroys the top_zap of this log vdev. + * + * This avoids the scenario where we flush a metaslab + * from the log vdev being removed that doesn't have a + * top_zap and end up failing to lookup its on-disk flush + * data. + * + * We don't call metaslab_group_destroy() right away + * though (it will be called in vdev_free() later) as + * during metaslab_sync() of metaslabs from other vdevs + * we may touch the metaslab group of this vdev through + * metaslab_class_histogram_verify() + */ + vdev_metaslab_fini(vd); + spa_log_sm_set_blocklimit(spa); + + spa_vdev_config_exit(spa, NULL, *txg, 0, FTAG); + *txg = spa_vdev_config_enter(spa); + + sysevent_t *ev = spa_event_create(spa, vd, NULL, + ESC_ZFS_VDEV_REMOVE_DEV); + ASSERT(MUTEX_HELD(&spa_namespace_lock)); + ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL); + + /* The top ZAP should have been destroyed by vdev_remove_empty. */ + ASSERT0(vd->vdev_top_zap); + /* The leaf ZAP should have been destroyed by vdev_dtl_sync. */ + ASSERT0(vd->vdev_leaf_zap); + + (void) vdev_label_init(vd, 0, VDEV_LABEL_REMOVE); + + if (list_link_active(&vd->vdev_state_dirty_node)) + vdev_state_clean(vd); + if (list_link_active(&vd->vdev_config_dirty_node)) + vdev_config_clean(vd); + + ASSERT0(vd->vdev_stat.vs_alloc); + + /* + * Clean up the vdev namespace. + */ + vdev_remove_make_hole_and_free(vd); + + if (ev != NULL) + spa_event_post(ev); + + return (0); +} + +static int +spa_vdev_remove_top_check(vdev_t *vd) +{ + spa_t *spa = vd->vdev_spa; + + if (vd != vd->vdev_top) + return (SET_ERROR(ENOTSUP)); + + if (!vdev_is_concrete(vd)) + return (SET_ERROR(ENOTSUP)); + + if (!spa_feature_is_enabled(spa, SPA_FEATURE_DEVICE_REMOVAL)) + return (SET_ERROR(ENOTSUP)); + + /* available space in the pool's normal class */ + uint64_t available = dsl_dir_space_available( + spa->spa_dsl_pool->dp_root_dir, NULL, 0, B_TRUE); + + metaslab_class_t *mc = vd->vdev_mg->mg_class; + + /* + * When removing a vdev from an allocation class that has + * remaining vdevs, include available space from the class. + */ + if (mc != spa_normal_class(spa) && mc->mc_groups > 1) { + uint64_t class_avail = metaslab_class_get_space(mc) - + metaslab_class_get_alloc(mc); + + /* add class space, adjusted for overhead */ + available += (class_avail * 94) / 100; + } + + /* + * There has to be enough free space to remove the + * device and leave double the "slop" space (i.e. we + * must leave at least 3% of the pool free, in addition to + * the normal slop space). + */ + if (available < vd->vdev_stat.vs_dspace + spa_get_slop_space(spa)) { + return (SET_ERROR(ENOSPC)); + } + + /* + * There can not be a removal in progress. + */ + if (spa->spa_removing_phys.sr_state == DSS_SCANNING) + return (SET_ERROR(EBUSY)); + + /* + * The device must have all its data. + */ + if (!vdev_dtl_empty(vd, DTL_MISSING) || + !vdev_dtl_empty(vd, DTL_OUTAGE)) + return (SET_ERROR(EBUSY)); + + /* + * The device must be healthy. + */ + if (!vdev_readable(vd)) + return (SET_ERROR(EIO)); + + /* + * All vdevs in normal class must have the same ashift. + */ + if (spa->spa_max_ashift != spa->spa_min_ashift) { + return (SET_ERROR(EINVAL)); + } + + /* + * All vdevs in normal class must have the same ashift + * and not be raidz. + */ + vdev_t *rvd = spa->spa_root_vdev; + int num_indirect = 0; + for (uint64_t id = 0; id < rvd->vdev_children; id++) { + vdev_t *cvd = rvd->vdev_child[id]; + if (cvd->vdev_ashift != 0 && !cvd->vdev_islog) + ASSERT3U(cvd->vdev_ashift, ==, spa->spa_max_ashift); + if (cvd->vdev_ops == &vdev_indirect_ops) + num_indirect++; + if (!vdev_is_concrete(cvd)) + continue; + if (cvd->vdev_ops == &vdev_raidz_ops) + return (SET_ERROR(EINVAL)); + /* + * Need the mirror to be mirror of leaf vdevs only + */ + if (cvd->vdev_ops == &vdev_mirror_ops) { + for (uint64_t cid = 0; + cid < cvd->vdev_children; cid++) { + if (!cvd->vdev_child[cid]->vdev_ops-> + vdev_op_leaf) + return (SET_ERROR(EINVAL)); + } + } + } + + return (0); +} + +/* + * Initiate removal of a top-level vdev, reducing the total space in the pool. + * The config lock is held for the specified TXG. Once initiated, + * evacuation of all allocated space (copying it to other vdevs) happens + * in the background (see spa_vdev_remove_thread()), and can be canceled + * (see spa_vdev_remove_cancel()). If successful, the vdev will + * be transformed to an indirect vdev (see spa_vdev_remove_complete()). + */ +static int +spa_vdev_remove_top(vdev_t *vd, uint64_t *txg) +{ + spa_t *spa = vd->vdev_spa; + int error; + + /* + * Check for errors up-front, so that we don't waste time + * passivating the metaslab group and clearing the ZIL if there + * are errors. + */ + error = spa_vdev_remove_top_check(vd); + if (error != 0) + return (error); + + /* + * Stop allocating from this vdev. Note that we must check + * that this is not the only device in the pool before + * passivating, otherwise we will not be able to make + * progress because we can't allocate from any vdevs. + * The above check for sufficient free space serves this + * purpose. + */ + metaslab_group_t *mg = vd->vdev_mg; + metaslab_group_passivate(mg); + + /* + * Wait for the youngest allocations and frees to sync, + * and then wait for the deferral of those frees to finish. + */ + spa_vdev_config_exit(spa, NULL, + *txg + TXG_CONCURRENT_STATES + TXG_DEFER_SIZE, 0, FTAG); + + /* + * We must ensure that no "stubby" log blocks are allocated + * on the device to be removed. These blocks could be + * written at any time, including while we are in the middle + * of copying them. + */ + error = spa_reset_logs(spa); + + /* + * We stop any initializing and TRIM that is currently in progress + * but leave the state as "active". This will allow the process to + * resume if the removal is canceled sometime later. + */ + vdev_initialize_stop_all(vd, VDEV_INITIALIZE_ACTIVE); + vdev_trim_stop_all(vd, VDEV_TRIM_ACTIVE); + vdev_autotrim_stop_wait(vd); + + *txg = spa_vdev_config_enter(spa); + + /* + * Things might have changed while the config lock was dropped + * (e.g. space usage). Check for errors again. + */ + if (error == 0) + error = spa_vdev_remove_top_check(vd); + + if (error != 0) { + metaslab_group_activate(mg); + spa_async_request(spa, SPA_ASYNC_INITIALIZE_RESTART); + spa_async_request(spa, SPA_ASYNC_TRIM_RESTART); + spa_async_request(spa, SPA_ASYNC_AUTOTRIM_RESTART); + return (error); + } + + vd->vdev_removing = B_TRUE; + + vdev_dirty_leaves(vd, VDD_DTL, *txg); + vdev_config_dirty(vd); + dmu_tx_t *tx = dmu_tx_create_assigned(spa->spa_dsl_pool, *txg); + dsl_sync_task_nowait(spa->spa_dsl_pool, + vdev_remove_initiate_sync, + (void *)(uintptr_t)vd->vdev_id, 0, ZFS_SPACE_CHECK_NONE, tx); + dmu_tx_commit(tx); + + return (0); +} + +/* + * Remove a device from the pool. + * + * Removing a device from the vdev namespace requires several steps + * and can take a significant amount of time. As a result we use + * the spa_vdev_config_[enter/exit] functions which allow us to + * grab and release the spa_config_lock while still holding the namespace + * lock. During each step the configuration is synced out. + */ +int +spa_vdev_remove(spa_t *spa, uint64_t guid, boolean_t unspare) +{ + vdev_t *vd; + nvlist_t **spares, **l2cache, *nv; + uint64_t txg = 0; + uint_t nspares, nl2cache; + int error = 0, error_log; + boolean_t locked = MUTEX_HELD(&spa_namespace_lock); + sysevent_t *ev = NULL; + char *vd_type = NULL, *vd_path = NULL; + + ASSERT(spa_writeable(spa)); + + if (!locked) + txg = spa_vdev_enter(spa); + + ASSERT(MUTEX_HELD(&spa_namespace_lock)); + if (spa_feature_is_active(spa, SPA_FEATURE_POOL_CHECKPOINT)) { + error = (spa_has_checkpoint(spa)) ? + ZFS_ERR_CHECKPOINT_EXISTS : ZFS_ERR_DISCARDING_CHECKPOINT; + + if (!locked) + return (spa_vdev_exit(spa, NULL, txg, error)); + + return (error); + } + + vd = spa_lookup_by_guid(spa, guid, B_FALSE); + + if (spa->spa_spares.sav_vdevs != NULL && + nvlist_lookup_nvlist_array(spa->spa_spares.sav_config, + ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0 && + (nv = spa_nvlist_lookup_by_guid(spares, nspares, guid)) != NULL) { + /* + * Only remove the hot spare if it's not currently in use + * in this pool. + */ + if (vd == NULL || unspare) { + if (vd == NULL) + vd = spa_lookup_by_guid(spa, guid, B_TRUE); + ev = spa_event_create(spa, vd, NULL, + ESC_ZFS_VDEV_REMOVE_AUX); + + vd_type = VDEV_TYPE_SPARE; + vd_path = spa_strdup(fnvlist_lookup_string( + nv, ZPOOL_CONFIG_PATH)); + spa_vdev_remove_aux(spa->spa_spares.sav_config, + ZPOOL_CONFIG_SPARES, spares, nspares, nv); + spa_load_spares(spa); + spa->spa_spares.sav_sync = B_TRUE; + } else { + error = SET_ERROR(EBUSY); + } + } else if (spa->spa_l2cache.sav_vdevs != NULL && + nvlist_lookup_nvlist_array(spa->spa_l2cache.sav_config, + ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0 && + (nv = spa_nvlist_lookup_by_guid(l2cache, nl2cache, guid)) != NULL) { + vd_type = VDEV_TYPE_L2CACHE; + vd_path = spa_strdup(fnvlist_lookup_string( + nv, ZPOOL_CONFIG_PATH)); + /* + * Cache devices can always be removed. + */ + vd = spa_lookup_by_guid(spa, guid, B_TRUE); + + /* + * Stop trimming the cache device. We need to release the + * config lock to allow the syncing of TRIM transactions + * without releasing the spa_namespace_lock. The same + * strategy is employed in spa_vdev_remove_top(). + */ + spa_vdev_config_exit(spa, NULL, + txg + TXG_CONCURRENT_STATES + TXG_DEFER_SIZE, 0, FTAG); + mutex_enter(&vd->vdev_trim_lock); + vdev_trim_stop(vd, VDEV_TRIM_CANCELED, NULL); + mutex_exit(&vd->vdev_trim_lock); + txg = spa_vdev_config_enter(spa); + + ev = spa_event_create(spa, vd, NULL, ESC_ZFS_VDEV_REMOVE_AUX); + spa_vdev_remove_aux(spa->spa_l2cache.sav_config, + ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache, nv); + spa_load_l2cache(spa); + spa->spa_l2cache.sav_sync = B_TRUE; + } else if (vd != NULL && vd->vdev_islog) { + ASSERT(!locked); + vd_type = VDEV_TYPE_LOG; + vd_path = spa_strdup((vd->vdev_path != NULL) ? + vd->vdev_path : "-"); + error = spa_vdev_remove_log(vd, &txg); + } else if (vd != NULL) { + ASSERT(!locked); + error = spa_vdev_remove_top(vd, &txg); + } else { + /* + * There is no vdev of any kind with the specified guid. + */ + error = SET_ERROR(ENOENT); + } + + error_log = error; + + if (!locked) + error = spa_vdev_exit(spa, NULL, txg, error); + + /* + * Logging must be done outside the spa config lock. Otherwise, + * this code path could end up holding the spa config lock while + * waiting for a txg_sync so it can write to the internal log. + * Doing that would prevent the txg sync from actually happening, + * causing a deadlock. + */ + if (error_log == 0 && vd_type != NULL && vd_path != NULL) { + spa_history_log_internal(spa, "vdev remove", NULL, + "%s vdev (%s) %s", spa_name(spa), vd_type, vd_path); + } + if (vd_path != NULL) + spa_strfree(vd_path); + + if (ev != NULL) + spa_event_post(ev); + + return (error); +} + +int +spa_removal_get_stats(spa_t *spa, pool_removal_stat_t *prs) +{ + prs->prs_state = spa->spa_removing_phys.sr_state; + + if (prs->prs_state == DSS_NONE) + return (SET_ERROR(ENOENT)); + + prs->prs_removing_vdev = spa->spa_removing_phys.sr_removing_vdev; + prs->prs_start_time = spa->spa_removing_phys.sr_start_time; + prs->prs_end_time = spa->spa_removing_phys.sr_end_time; + prs->prs_to_copy = spa->spa_removing_phys.sr_to_copy; + prs->prs_copied = spa->spa_removing_phys.sr_copied; + + prs->prs_mapping_memory = 0; + uint64_t indirect_vdev_id = + spa->spa_removing_phys.sr_prev_indirect_vdev; + while (indirect_vdev_id != -1) { + vdev_t *vd = spa->spa_root_vdev->vdev_child[indirect_vdev_id]; + vdev_indirect_config_t *vic = &vd->vdev_indirect_config; + vdev_indirect_mapping_t *vim = vd->vdev_indirect_mapping; + + ASSERT3P(vd->vdev_ops, ==, &vdev_indirect_ops); + prs->prs_mapping_memory += vdev_indirect_mapping_size(vim); + indirect_vdev_id = vic->vic_prev_indirect_vdev; + } + + return (0); +} + +/* BEGIN CSTYLED */ +ZFS_MODULE_PARAM(zfs_vdev, zfs_, removal_ignore_errors, INT, ZMOD_RW, + "Ignore hard IO errors when removing device"); + +ZFS_MODULE_PARAM(zfs_vdev, zfs_, remove_max_segment, INT, ZMOD_RW, + "Largest contiguous segment to allocate when removing device"); + +ZFS_MODULE_PARAM(zfs_vdev, vdev_, removal_max_span, INT, ZMOD_RW, + "Largest span of free chunks a remap segment can span"); + +ZFS_MODULE_PARAM(zfs_vdev, zfs_, removal_suspend_progress, INT, ZMOD_RW, + "Pause device removal after this many bytes are copied " + "(debug use only - causes removal to hang)"); +/* END CSTYLED */ + +EXPORT_SYMBOL(free_from_removing_vdev); +EXPORT_SYMBOL(spa_removal_get_stats); +EXPORT_SYMBOL(spa_remove_init); +EXPORT_SYMBOL(spa_restart_removal); +EXPORT_SYMBOL(spa_vdev_removal_destroy); +EXPORT_SYMBOL(spa_vdev_remove); +EXPORT_SYMBOL(spa_vdev_remove_cancel); +EXPORT_SYMBOL(spa_vdev_remove_suspend); +EXPORT_SYMBOL(svr_sync); |