/* * 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) 2016, 2019 by Delphix. All rights reserved. */ #include #include #include #include #include #include #include #include #include /* * Value that is written to disk during initialization. */ uint64_t zfs_initialize_value = 0xdeadbeefdeadbeefULL; /* maximum number of I/Os outstanding per leaf vdev */ int zfs_initialize_limit = 1; /* size of initializing writes; default 1MiB, see zfs_remove_max_segment */ uint64_t zfs_initialize_chunk_size = 1024 * 1024; static boolean_t vdev_initialize_should_stop(vdev_t *vd) { return (vd->vdev_initialize_exit_wanted || !vdev_writeable(vd) || vd->vdev_detached || vd->vdev_top->vdev_removing); } static void vdev_initialize_zap_update_sync(void *arg, dmu_tx_t *tx) { /* * We pass in the guid instead of the vdev_t since the vdev may * have been freed prior to the sync task being processed. This * happens when a vdev is detached as we call spa_config_vdev_exit(), * stop the initializing thread, schedule the sync task, and free * the vdev. Later when the scheduled sync task is invoked, it would * find that the vdev has been freed. */ uint64_t guid = *(uint64_t *)arg; uint64_t txg = dmu_tx_get_txg(tx); kmem_free(arg, sizeof (uint64_t)); vdev_t *vd = spa_lookup_by_guid(tx->tx_pool->dp_spa, guid, B_FALSE); if (vd == NULL || vd->vdev_top->vdev_removing || !vdev_is_concrete(vd)) return; uint64_t last_offset = vd->vdev_initialize_offset[txg & TXG_MASK]; vd->vdev_initialize_offset[txg & TXG_MASK] = 0; VERIFY(vd->vdev_leaf_zap != 0); objset_t *mos = vd->vdev_spa->spa_meta_objset; if (last_offset > 0) { vd->vdev_initialize_last_offset = last_offset; VERIFY0(zap_update(mos, vd->vdev_leaf_zap, VDEV_LEAF_ZAP_INITIALIZE_LAST_OFFSET, sizeof (last_offset), 1, &last_offset, tx)); } if (vd->vdev_initialize_action_time > 0) { uint64_t val = (uint64_t)vd->vdev_initialize_action_time; VERIFY0(zap_update(mos, vd->vdev_leaf_zap, VDEV_LEAF_ZAP_INITIALIZE_ACTION_TIME, sizeof (val), 1, &val, tx)); } uint64_t initialize_state = vd->vdev_initialize_state; VERIFY0(zap_update(mos, vd->vdev_leaf_zap, VDEV_LEAF_ZAP_INITIALIZE_STATE, sizeof (initialize_state), 1, &initialize_state, tx)); } static void vdev_initialize_change_state(vdev_t *vd, vdev_initializing_state_t new_state) { ASSERT(MUTEX_HELD(&vd->vdev_initialize_lock)); spa_t *spa = vd->vdev_spa; if (new_state == vd->vdev_initialize_state) return; /* * Copy the vd's guid, this will be freed by the sync task. */ uint64_t *guid = kmem_zalloc(sizeof (uint64_t), KM_SLEEP); *guid = vd->vdev_guid; /* * If we're suspending, then preserving the original start time. */ if (vd->vdev_initialize_state != VDEV_INITIALIZE_SUSPENDED) { vd->vdev_initialize_action_time = gethrestime_sec(); } vd->vdev_initialize_state = new_state; dmu_tx_t *tx = dmu_tx_create_dd(spa_get_dsl(spa)->dp_mos_dir); VERIFY0(dmu_tx_assign(tx, TXG_WAIT)); dsl_sync_task_nowait(spa_get_dsl(spa), vdev_initialize_zap_update_sync, guid, 2, ZFS_SPACE_CHECK_NONE, tx); switch (new_state) { case VDEV_INITIALIZE_ACTIVE: spa_history_log_internal(spa, "initialize", tx, "vdev=%s activated", vd->vdev_path); break; case VDEV_INITIALIZE_SUSPENDED: spa_history_log_internal(spa, "initialize", tx, "vdev=%s suspended", vd->vdev_path); break; case VDEV_INITIALIZE_CANCELED: spa_history_log_internal(spa, "initialize", tx, "vdev=%s canceled", vd->vdev_path); break; case VDEV_INITIALIZE_COMPLETE: spa_history_log_internal(spa, "initialize", tx, "vdev=%s complete", vd->vdev_path); break; default: panic("invalid state %llu", (unsigned long long)new_state); } dmu_tx_commit(tx); } static void vdev_initialize_cb(zio_t *zio) { vdev_t *vd = zio->io_vd; mutex_enter(&vd->vdev_initialize_io_lock); if (zio->io_error == ENXIO && !vdev_writeable(vd)) { /* * The I/O failed because the vdev was unavailable; roll the * last offset back. (This works because spa_sync waits on * spa_txg_zio before it runs sync tasks.) */ uint64_t *off = &vd->vdev_initialize_offset[zio->io_txg & TXG_MASK]; *off = MIN(*off, zio->io_offset); } else { /* * Since initializing is best-effort, we ignore I/O errors and * rely on vdev_probe to determine if the errors are more * critical. */ if (zio->io_error != 0) vd->vdev_stat.vs_initialize_errors++; vd->vdev_initialize_bytes_done += zio->io_orig_size; } ASSERT3U(vd->vdev_initialize_inflight, >, 0); vd->vdev_initialize_inflight--; cv_broadcast(&vd->vdev_initialize_io_cv); mutex_exit(&vd->vdev_initialize_io_lock); spa_config_exit(vd->vdev_spa, SCL_STATE_ALL, vd); } /* Takes care of physical writing and limiting # of concurrent ZIOs. */ static int vdev_initialize_write(vdev_t *vd, uint64_t start, uint64_t size, abd_t *data) { spa_t *spa = vd->vdev_spa; /* Limit inflight initializing I/Os */ mutex_enter(&vd->vdev_initialize_io_lock); while (vd->vdev_initialize_inflight >= zfs_initialize_limit) { cv_wait(&vd->vdev_initialize_io_cv, &vd->vdev_initialize_io_lock); } vd->vdev_initialize_inflight++; mutex_exit(&vd->vdev_initialize_io_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); spa_config_enter(spa, SCL_STATE_ALL, vd, RW_READER); mutex_enter(&vd->vdev_initialize_lock); if (vd->vdev_initialize_offset[txg & TXG_MASK] == 0) { uint64_t *guid = kmem_zalloc(sizeof (uint64_t), KM_SLEEP); *guid = vd->vdev_guid; /* This is the first write of this txg. */ dsl_sync_task_nowait(spa_get_dsl(spa), vdev_initialize_zap_update_sync, guid, 2, ZFS_SPACE_CHECK_RESERVED, tx); } /* * We know the vdev struct will still be around since all * consumers of vdev_free must stop the initialization first. */ if (vdev_initialize_should_stop(vd)) { mutex_enter(&vd->vdev_initialize_io_lock); ASSERT3U(vd->vdev_initialize_inflight, >, 0); vd->vdev_initialize_inflight--; mutex_exit(&vd->vdev_initialize_io_lock); spa_config_exit(vd->vdev_spa, SCL_STATE_ALL, vd); mutex_exit(&vd->vdev_initialize_lock); dmu_tx_commit(tx); return (SET_ERROR(EINTR)); } mutex_exit(&vd->vdev_initialize_lock); vd->vdev_initialize_offset[txg & TXG_MASK] = start + size; zio_nowait(zio_write_phys(spa->spa_txg_zio[txg & TXG_MASK], vd, start, size, data, ZIO_CHECKSUM_OFF, vdev_initialize_cb, NULL, ZIO_PRIORITY_INITIALIZING, ZIO_FLAG_CANFAIL, B_FALSE)); /* vdev_initialize_cb releases SCL_STATE_ALL */ dmu_tx_commit(tx); return (0); } /* * Callback to fill each ABD chunk with zfs_initialize_value. len must be * divisible by sizeof (uint64_t), and buf must be 8-byte aligned. The ABD * allocation will guarantee these for us. */ /* ARGSUSED */ static int vdev_initialize_block_fill(void *buf, size_t len, void *unused) { ASSERT0(len % sizeof (uint64_t)); for (uint64_t i = 0; i < len; i += sizeof (uint64_t)) { *(uint64_t *)((char *)(buf) + i) = zfs_initialize_value; } return (0); } static abd_t * vdev_initialize_block_alloc() { /* Allocate ABD for filler data */ abd_t *data = abd_alloc_for_io(zfs_initialize_chunk_size, B_FALSE); ASSERT0(zfs_initialize_chunk_size % sizeof (uint64_t)); (void) abd_iterate_func(data, 0, zfs_initialize_chunk_size, vdev_initialize_block_fill, NULL); return (data); } static void vdev_initialize_block_free(abd_t *data) { abd_free(data); } static int vdev_initialize_ranges(vdev_t *vd, abd_t *data) { range_tree_t *rt = vd->vdev_initialize_tree; zfs_btree_t *bt = &rt->rt_root; zfs_btree_index_t where; for (range_seg_t *rs = zfs_btree_first(bt, &where); rs != NULL; rs = zfs_btree_next(bt, &where, &where)) { uint64_t size = rs_get_end(rs, rt) - rs_get_start(rs, rt); /* Split range into legally-sized physical chunks */ uint64_t writes_required = ((size - 1) / zfs_initialize_chunk_size) + 1; for (uint64_t w = 0; w < writes_required; w++) { int error; error = vdev_initialize_write(vd, VDEV_LABEL_START_SIZE + rs_get_start(rs, rt) + (w * zfs_initialize_chunk_size), MIN(size - (w * zfs_initialize_chunk_size), zfs_initialize_chunk_size), data); if (error != 0) return (error); } } return (0); } static void vdev_initialize_calculate_progress(vdev_t *vd) { ASSERT(spa_config_held(vd->vdev_spa, SCL_CONFIG, RW_READER) || spa_config_held(vd->vdev_spa, SCL_CONFIG, RW_WRITER)); ASSERT(vd->vdev_leaf_zap != 0); vd->vdev_initialize_bytes_est = 0; vd->vdev_initialize_bytes_done = 0; for (uint64_t i = 0; i < vd->vdev_top->vdev_ms_count; i++) { metaslab_t *msp = vd->vdev_top->vdev_ms[i]; mutex_enter(&msp->ms_lock); uint64_t ms_free = msp->ms_size - metaslab_allocated_space(msp); if (vd->vdev_top->vdev_ops == &vdev_raidz_ops) ms_free /= vd->vdev_top->vdev_children; /* * Convert the metaslab range to a physical range * on our vdev. We use this to determine if we are * in the middle of this metaslab range. */ range_seg64_t logical_rs, physical_rs; logical_rs.rs_start = msp->ms_start; logical_rs.rs_end = msp->ms_start + msp->ms_size; vdev_xlate(vd, &logical_rs, &physical_rs); if (vd->vdev_initialize_last_offset <= physical_rs.rs_start) { vd->vdev_initialize_bytes_est += ms_free; mutex_exit(&msp->ms_lock); continue; } else if (vd->vdev_initialize_last_offset > physical_rs.rs_end) { vd->vdev_initialize_bytes_done += ms_free; vd->vdev_initialize_bytes_est += ms_free; mutex_exit(&msp->ms_lock); continue; } /* * If we get here, we're in the middle of initializing this * metaslab. Load it and walk the free tree for more accurate * progress estimation. */ VERIFY0(metaslab_load(msp)); zfs_btree_index_t where; range_tree_t *rt = msp->ms_allocatable; for (range_seg_t *rs = zfs_btree_first(&rt->rt_root, &where); rs; rs = zfs_btree_next(&rt->rt_root, &where, &where)) { logical_rs.rs_start = rs_get_start(rs, rt); logical_rs.rs_end = rs_get_end(rs, rt); vdev_xlate(vd, &logical_rs, &physical_rs); uint64_t size = physical_rs.rs_end - physical_rs.rs_start; vd->vdev_initialize_bytes_est += size; if (vd->vdev_initialize_last_offset > physical_rs.rs_end) { vd->vdev_initialize_bytes_done += size; } else if (vd->vdev_initialize_last_offset > physical_rs.rs_start && vd->vdev_initialize_last_offset < physical_rs.rs_end) { vd->vdev_initialize_bytes_done += vd->vdev_initialize_last_offset - physical_rs.rs_start; } } mutex_exit(&msp->ms_lock); } } static int vdev_initialize_load(vdev_t *vd) { int err = 0; ASSERT(spa_config_held(vd->vdev_spa, SCL_CONFIG, RW_READER) || spa_config_held(vd->vdev_spa, SCL_CONFIG, RW_WRITER)); ASSERT(vd->vdev_leaf_zap != 0); if (vd->vdev_initialize_state == VDEV_INITIALIZE_ACTIVE || vd->vdev_initialize_state == VDEV_INITIALIZE_SUSPENDED) { err = zap_lookup(vd->vdev_spa->spa_meta_objset, vd->vdev_leaf_zap, VDEV_LEAF_ZAP_INITIALIZE_LAST_OFFSET, sizeof (vd->vdev_initialize_last_offset), 1, &vd->vdev_initialize_last_offset); if (err == ENOENT) { vd->vdev_initialize_last_offset = 0; err = 0; } } vdev_initialize_calculate_progress(vd); return (err); } /* * Convert the logical range into a physical range and add it to our * avl tree. */ void vdev_initialize_range_add(void *arg, uint64_t start, uint64_t size) { vdev_t *vd = arg; range_seg64_t logical_rs, physical_rs; logical_rs.rs_start = start; logical_rs.rs_end = start + size; ASSERT(vd->vdev_ops->vdev_op_leaf); vdev_xlate(vd, &logical_rs, &physical_rs); IMPLY(vd->vdev_top == vd, logical_rs.rs_start == physical_rs.rs_start); IMPLY(vd->vdev_top == vd, logical_rs.rs_end == physical_rs.rs_end); /* Only add segments that we have not visited yet */ if (physical_rs.rs_end <= vd->vdev_initialize_last_offset) return; /* Pick up where we left off mid-range. */ if (vd->vdev_initialize_last_offset > physical_rs.rs_start) { zfs_dbgmsg("range write: vd %s changed (%llu, %llu) to " "(%llu, %llu)", vd->vdev_path, (u_longlong_t)physical_rs.rs_start, (u_longlong_t)physical_rs.rs_end, (u_longlong_t)vd->vdev_initialize_last_offset, (u_longlong_t)physical_rs.rs_end); ASSERT3U(physical_rs.rs_end, >, vd->vdev_initialize_last_offset); physical_rs.rs_start = vd->vdev_initialize_last_offset; } ASSERT3U(physical_rs.rs_end, >=, physical_rs.rs_start); /* * With raidz, it's possible that the logical range does not live on * this leaf vdev. We only add the physical range to this vdev's if it * has a length greater than 0. */ if (physical_rs.rs_end > physical_rs.rs_start) { range_tree_add(vd->vdev_initialize_tree, physical_rs.rs_start, physical_rs.rs_end - physical_rs.rs_start); } else { ASSERT3U(physical_rs.rs_end, ==, physical_rs.rs_start); } } static void vdev_initialize_thread(void *arg) { vdev_t *vd = arg; spa_t *spa = vd->vdev_spa; int error = 0; uint64_t ms_count = 0; ASSERT(vdev_is_concrete(vd)); spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER); vd->vdev_initialize_last_offset = 0; VERIFY0(vdev_initialize_load(vd)); abd_t *deadbeef = vdev_initialize_block_alloc(); vd->vdev_initialize_tree = range_tree_create(NULL, RANGE_SEG64, NULL, 0, 0); for (uint64_t i = 0; !vd->vdev_detached && i < vd->vdev_top->vdev_ms_count; i++) { metaslab_t *msp = vd->vdev_top->vdev_ms[i]; boolean_t unload_when_done = B_FALSE; /* * If we've expanded the top-level vdev or it's our * first pass, calculate our progress. */ if (vd->vdev_top->vdev_ms_count != ms_count) { vdev_initialize_calculate_progress(vd); ms_count = vd->vdev_top->vdev_ms_count; } spa_config_exit(spa, SCL_CONFIG, FTAG); metaslab_disable(msp); mutex_enter(&msp->ms_lock); if (!msp->ms_loaded && !msp->ms_loading) unload_when_done = B_TRUE; VERIFY0(metaslab_load(msp)); range_tree_walk(msp->ms_allocatable, vdev_initialize_range_add, vd); mutex_exit(&msp->ms_lock); error = vdev_initialize_ranges(vd, deadbeef); metaslab_enable(msp, B_TRUE, unload_when_done); spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER); range_tree_vacate(vd->vdev_initialize_tree, NULL, NULL); if (error != 0) break; } spa_config_exit(spa, SCL_CONFIG, FTAG); mutex_enter(&vd->vdev_initialize_io_lock); while (vd->vdev_initialize_inflight > 0) { cv_wait(&vd->vdev_initialize_io_cv, &vd->vdev_initialize_io_lock); } mutex_exit(&vd->vdev_initialize_io_lock); range_tree_destroy(vd->vdev_initialize_tree); vdev_initialize_block_free(deadbeef); vd->vdev_initialize_tree = NULL; mutex_enter(&vd->vdev_initialize_lock); if (!vd->vdev_initialize_exit_wanted && vdev_writeable(vd)) { vdev_initialize_change_state(vd, VDEV_INITIALIZE_COMPLETE); } ASSERT(vd->vdev_initialize_thread != NULL || vd->vdev_initialize_inflight == 0); /* * Drop the vdev_initialize_lock while we sync out the * txg since it's possible that a device might be trying to * come online and must check to see if it needs to restart an * initialization. That thread will be holding the spa_config_lock * which would prevent the txg_wait_synced from completing. */ mutex_exit(&vd->vdev_initialize_lock); txg_wait_synced(spa_get_dsl(spa), 0); mutex_enter(&vd->vdev_initialize_lock); vd->vdev_initialize_thread = NULL; cv_broadcast(&vd->vdev_initialize_cv); mutex_exit(&vd->vdev_initialize_lock); } /* * Initiates a device. Caller must hold vdev_initialize_lock. * Device must be a leaf and not already be initializing. */ void vdev_initialize(vdev_t *vd) { ASSERT(MUTEX_HELD(&vd->vdev_initialize_lock)); ASSERT(vd->vdev_ops->vdev_op_leaf); ASSERT(vdev_is_concrete(vd)); ASSERT3P(vd->vdev_initialize_thread, ==, NULL); ASSERT(!vd->vdev_detached); ASSERT(!vd->vdev_initialize_exit_wanted); ASSERT(!vd->vdev_top->vdev_removing); vdev_initialize_change_state(vd, VDEV_INITIALIZE_ACTIVE); vd->vdev_initialize_thread = thread_create(NULL, 0, vdev_initialize_thread, vd, 0, &p0, TS_RUN, maxclsyspri); } /* * Wait for the initialize thread to be terminated (cancelled or stopped). */ static void vdev_initialize_stop_wait_impl(vdev_t *vd) { ASSERT(MUTEX_HELD(&vd->vdev_initialize_lock)); while (vd->vdev_initialize_thread != NULL) cv_wait(&vd->vdev_initialize_cv, &vd->vdev_initialize_lock); ASSERT3P(vd->vdev_initialize_thread, ==, NULL); vd->vdev_initialize_exit_wanted = B_FALSE; } /* * Wait for vdev initialize threads which were either to cleanly exit. */ void vdev_initialize_stop_wait(spa_t *spa, list_t *vd_list) { vdev_t *vd; ASSERT(MUTEX_HELD(&spa_namespace_lock)); while ((vd = list_remove_head(vd_list)) != NULL) { mutex_enter(&vd->vdev_initialize_lock); vdev_initialize_stop_wait_impl(vd); mutex_exit(&vd->vdev_initialize_lock); } } /* * Stop initializing a device, with the resultant initializing state being * tgt_state. For blocking behavior pass NULL for vd_list. Otherwise, when * a list_t is provided the stopping vdev is inserted in to the list. Callers * are then required to call vdev_initialize_stop_wait() to block for all the * initialization threads to exit. The caller must hold vdev_initialize_lock * and must not be writing to the spa config, as the initializing thread may * try to enter the config as a reader before exiting. */ void vdev_initialize_stop(vdev_t *vd, vdev_initializing_state_t tgt_state, list_t *vd_list) { ASSERT(!spa_config_held(vd->vdev_spa, SCL_CONFIG|SCL_STATE, RW_WRITER)); ASSERT(MUTEX_HELD(&vd->vdev_initialize_lock)); ASSERT(vd->vdev_ops->vdev_op_leaf); ASSERT(vdev_is_concrete(vd)); /* * Allow cancel requests to proceed even if the initialize thread * has stopped. */ if (vd->vdev_initialize_thread == NULL && tgt_state != VDEV_INITIALIZE_CANCELED) { return; } vdev_initialize_change_state(vd, tgt_state); vd->vdev_initialize_exit_wanted = B_TRUE; if (vd_list == NULL) { vdev_initialize_stop_wait_impl(vd); } else { ASSERT(MUTEX_HELD(&spa_namespace_lock)); list_insert_tail(vd_list, vd); } } static void vdev_initialize_stop_all_impl(vdev_t *vd, vdev_initializing_state_t tgt_state, list_t *vd_list) { if (vd->vdev_ops->vdev_op_leaf && vdev_is_concrete(vd)) { mutex_enter(&vd->vdev_initialize_lock); vdev_initialize_stop(vd, tgt_state, vd_list); mutex_exit(&vd->vdev_initialize_lock); return; } for (uint64_t i = 0; i < vd->vdev_children; i++) { vdev_initialize_stop_all_impl(vd->vdev_child[i], tgt_state, vd_list); } } /* * Convenience function to stop initializing of a vdev tree and set all * initialize thread pointers to NULL. */ void vdev_initialize_stop_all(vdev_t *vd, vdev_initializing_state_t tgt_state) { spa_t *spa = vd->vdev_spa; list_t vd_list; ASSERT(MUTEX_HELD(&spa_namespace_lock)); list_create(&vd_list, sizeof (vdev_t), offsetof(vdev_t, vdev_initialize_node)); vdev_initialize_stop_all_impl(vd, tgt_state, &vd_list); vdev_initialize_stop_wait(spa, &vd_list); if (vd->vdev_spa->spa_sync_on) { /* Make sure that our state has been synced to disk */ txg_wait_synced(spa_get_dsl(vd->vdev_spa), 0); } list_destroy(&vd_list); } void vdev_initialize_restart(vdev_t *vd) { ASSERT(MUTEX_HELD(&spa_namespace_lock)); ASSERT(!spa_config_held(vd->vdev_spa, SCL_ALL, RW_WRITER)); if (vd->vdev_leaf_zap != 0) { mutex_enter(&vd->vdev_initialize_lock); uint64_t initialize_state = VDEV_INITIALIZE_NONE; int err = zap_lookup(vd->vdev_spa->spa_meta_objset, vd->vdev_leaf_zap, VDEV_LEAF_ZAP_INITIALIZE_STATE, sizeof (initialize_state), 1, &initialize_state); ASSERT(err == 0 || err == ENOENT); vd->vdev_initialize_state = initialize_state; uint64_t timestamp = 0; err = zap_lookup(vd->vdev_spa->spa_meta_objset, vd->vdev_leaf_zap, VDEV_LEAF_ZAP_INITIALIZE_ACTION_TIME, sizeof (timestamp), 1, ×tamp); ASSERT(err == 0 || err == ENOENT); vd->vdev_initialize_action_time = (time_t)timestamp; if (vd->vdev_initialize_state == VDEV_INITIALIZE_SUSPENDED || vd->vdev_offline) { /* load progress for reporting, but don't resume */ VERIFY0(vdev_initialize_load(vd)); } else if (vd->vdev_initialize_state == VDEV_INITIALIZE_ACTIVE && vdev_writeable(vd) && !vd->vdev_top->vdev_removing && vd->vdev_initialize_thread == NULL) { vdev_initialize(vd); } mutex_exit(&vd->vdev_initialize_lock); } for (uint64_t i = 0; i < vd->vdev_children; i++) { vdev_initialize_restart(vd->vdev_child[i]); } }