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zfs/module/zfs/vdev_removal.c

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/*
* 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 https://opensource.org/licenses/CDDL-1.0.
* 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, 2020 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.
*/
static const uint_t 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().
*/
uint_t 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.
*/
static 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
*/
uint_t 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 __attribute__((noreturn)) 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
vdev_activate(vdev_t *vd)
{
metaslab_group_t *mg = vd->vdev_mg;
spa_t *spa = vd->vdev_spa;
uint64_t vdev_space = spa_deflate(spa) ?
vd->vdev_stat.vs_dspace : vd->vdev_stat.vs_space;
ASSERT(!vd->vdev_islog);
ASSERT(vd->vdev_noalloc);
metaslab_group_activate(mg);
metaslab_group_activate(vd->vdev_log_mg);
ASSERT3U(spa->spa_nonallocating_dspace, >=, vdev_space);
spa->spa_nonallocating_dspace -= vdev_space;
vd->vdev_noalloc = B_FALSE;
}
static int
vdev_passivate(vdev_t *vd, uint64_t *txg)
{
spa_t *spa = vd->vdev_spa;
int error;
ASSERT(!vd->vdev_noalloc);
vdev_t *rvd = spa->spa_root_vdev;
metaslab_group_t *mg = vd->vdev_mg;
metaslab_class_t *normal = spa_normal_class(spa);
if (mg->mg_class == normal) {
/*
* We must check that this is not the only allocating device in
* the pool before passivating, otherwise we will not be able
* to make progress because we can't allocate from any vdevs.
*/
boolean_t last = B_TRUE;
for (uint64_t id = 0; id < rvd->vdev_children; id++) {
vdev_t *cvd = rvd->vdev_child[id];
if (cvd == vd ||
cvd->vdev_ops == &vdev_indirect_ops)
continue;
metaslab_class_t *mc = cvd->vdev_mg->mg_class;
if (mc != normal)
continue;
if (!cvd->vdev_noalloc) {
last = B_FALSE;
break;
}
}
if (last)
return (SET_ERROR(EINVAL));
}
metaslab_group_passivate(mg);
ASSERT(!vd->vdev_islog);
metaslab_group_passivate(vd->vdev_log_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);
*txg = spa_vdev_config_enter(spa);
if (error != 0) {
metaslab_group_activate(mg);
ASSERT(!vd->vdev_islog);
if (vd->vdev_log_mg != NULL)
metaslab_group_activate(vd->vdev_log_mg);
return (error);
}
spa->spa_nonallocating_dspace += spa_deflate(spa) ?
vd->vdev_stat.vs_dspace : vd->vdev_stat.vs_space;
vd->vdev_noalloc = B_TRUE;
return (0);
}
/*
* Turn off allocations for a top-level device from the pool.
*
* Turning off allocations for a top-level device 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_noalloc(spa_t *spa, uint64_t guid)
{
vdev_t *vd;
uint64_t txg;
int error = 0;
ASSERT(!MUTEX_HELD(&spa_namespace_lock));
ASSERT(spa_writeable(spa));
txg = spa_vdev_enter(spa);
ASSERT(MUTEX_HELD(&spa_namespace_lock));
vd = spa_lookup_by_guid(spa, guid, B_FALSE);
if (vd == NULL)
error = SET_ERROR(ENOENT);
else if (vd->vdev_mg == NULL)
error = SET_ERROR(ZFS_ERR_VDEV_NOTSUP);
else if (!vd->vdev_noalloc)
error = vdev_passivate(vd, &txg);
if (error == 0) {
vdev_dirty_leaves(vd, VDD_DTL, txg);
vdev_config_dirty(vd);
}
error = spa_vdev_exit(spa, NULL, txg, error);
return (error);
}
int
spa_vdev_alloc(spa_t *spa, uint64_t guid)
{
vdev_t *vd;
uint64_t txg;
int error = 0;
ASSERT(!MUTEX_HELD(&spa_namespace_lock));
ASSERT(spa_writeable(spa));
txg = spa_vdev_enter(spa);
ASSERT(MUTEX_HELD(&spa_namespace_lock));
vd = spa_lookup_by_guid(spa, guid, B_FALSE);
if (vd == NULL)
error = SET_ERROR(ENOENT);
else if (vd->vdev_mg == NULL)
error = SET_ERROR(ZFS_ERR_VDEV_NOTSUP);
else if (!vd->vdev_removing)
vdev_activate(vd);
if (error == 0) {
vdev_dirty_leaves(vd, VDD_DTL, txg);
vdev_config_dirty(vd);
}
(void) spa_vdev_exit(spa, NULL, txg, error);
return (error);
}
static void
spa_vdev_remove_aux(nvlist_t *config, const 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);
fnvlist_add_nvlist_array(config, name, (const nvlist_t * const *)newdev,
count - 1);
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);
ASSERT0(vdev_get_nparity(vd));
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", (u_longlong_t)vd->vdev_id, vd,
(u_longlong_t)dmu_tx_get_txg(tx),
(u_longlong_t)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",
(u_longlong_t)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->mc_groups == 0)
mc = spa_normal_class(spa);
int error = metaslab_alloc_dva(spa, mc, size, &dst, 0, NULL, txg,
METASLAB_DONT_THROTTLE, zal, 0);
if (error == ENOSPC && mc != spa_normal_class(spa)) {
error = metaslab_alloc_dva(spa, spa_normal_class(spa), size,
&dst, 0, NULL, txg, METASLAB_DONT_THROTTLE, 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);
ASSERT0(vdev_get_nparity(vd));
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, 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);
vdev_rebuild_stop_wait(vd);
ASSERT3P(vd->vdev_rebuild_thread, ==, NULL);
uint64_t vdev_space = spa_deflate(spa) ?
vd->vdev_stat.vs_dspace : vd->vdev_stat.vs_space;
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",
(u_longlong_t)vd->vdev_id, (u_longlong_t)txg);
ASSERT3U(0, !=, vdev_space);
ASSERT3U(spa->spa_nonallocating_dspace, >=, vdev_space);
/* the vdev is no longer part of the dspace */
spa->spa_nonallocating_dspace -= vdev_space;
/*
* Discard allocation state.
*/
if (vd->vdev_mg != NULL) {
vdev_metaslab_fini(vd);
metaslab_group_destroy(vd->vdev_mg);
vd->vdev_mg = NULL;
}
if (vd->vdev_log_mg != NULL) {
ASSERT0(vd->vdev_ms_count);
metaslab_group_destroy(vd->vdev_log_mg);
vd->vdev_log_mg = NULL;
}
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, 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 __attribute__((noreturn)) 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",
(u_longlong_t)zfs_btree_numnodes(
&svr->svr_allocd_segs->rt_root),
(u_longlong_t)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.
*/
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]",
(u_longlong_t)vca.vca_read_error_bytes,
(u_longlong_t)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);
}
/*
* Return true if the "allocating" property has been set to "off"
*/
static boolean_t
vdev_prop_allocating_off(vdev_t *vd)
{
uint64_t objid = vd->vdev_top_zap;
uint64_t allocating = 1;
/* no vdev property object => no props */
if (objid != 0) {
spa_t *spa = vd->vdev_spa;
objset_t *mos = spa->spa_meta_objset;
mutex_enter(&spa->spa_props_lock);
(void) zap_lookup(mos, objid, "allocating", sizeof (uint64_t),
1, &allocating);
mutex_exit(&spa->spa_props_lock);
}
return (allocating == 0);
}
static int
spa_vdev_remove_cancel_check(void *arg, dmu_tx_t *tx)
{
(void) arg;
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.
*/
static void
spa_vdev_remove_cancel_sync(void *arg, dmu_tx_t *tx)
{
(void) arg;
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;
if (!vdev_prop_allocating_off(vd)) {
spa_config_enter(spa, SCL_ALLOC | SCL_VDEV, FTAG, RW_WRITER);
vdev_activate(vd);
spa_config_exit(spa, SCL_ALLOC | SCL_VDEV, FTAG);
}
vdev_config_dirty(vd);
zfs_dbgmsg("canceled device removal for vdev %llu in %llu",
(u_longlong_t)vd->vdev_id, (u_longlong_t)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)
{
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);
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);
ASSERT3P(vd->vdev_log_mg, ==, NULL);
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);
ASSERT3P(vd->vdev_log_mg, ==, NULL);
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_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));
/*
* This device is already being removed
*/
if (vd->vdev_removing)
return (SET_ERROR(EALREADY));
metaslab_class_t *mc = vd->vdev_mg->mg_class;
metaslab_class_t *normal = spa_normal_class(spa);
if (mc != normal) {
/*
* Space allocated from the special (or dedup) class is
* included in the DMU's space usage, but it's not included
* in spa_dspace (or dsl_pool_adjustedsize()). Therefore
* there is always at least as much free space in the normal
* class, as is allocated from the special (and dedup) class.
* As a backup check, we will return ENOSPC if this is
* violated. See also spa_update_dspace().
*/
uint64_t available = metaslab_class_get_space(normal) -
metaslab_class_get_alloc(normal);
ASSERT3U(available, >=, vd->vdev_stat.vs_alloc);
if (available < vd->vdev_stat.vs_alloc)
return (SET_ERROR(ENOSPC));
} else if (!vd->vdev_noalloc) {
/* 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);
if (available < vd->vdev_stat.vs_dspace)
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));
}
/*
* A removed special/dedup vdev must have same ashift as normal class.
*/
ASSERT(!vd->vdev_islog);
if (vd->vdev_alloc_bias != VDEV_BIAS_NONE &&
vd->vdev_ashift != spa->spa_max_ashift) {
return (SET_ERROR(EINVAL));
}
/*
* All vdevs in normal class must have the same ashift
* and not be raidz or draid.
*/
vdev_t *rvd = spa->spa_root_vdev;
for (uint64_t id = 0; id < rvd->vdev_children; id++) {
vdev_t *cvd = rvd->vdev_child[id];
/*
* A removed special/dedup vdev must have the same ashift
* across all vdevs in its class.
*/
if (vd->vdev_alloc_bias != VDEV_BIAS_NONE &&
cvd->vdev_alloc_bias == vd->vdev_alloc_bias &&
cvd->vdev_ashift != vd->vdev_ashift) {
return (SET_ERROR(EINVAL));
}
if (cvd->vdev_ashift != 0 &&
cvd->vdev_alloc_bias == VDEV_BIAS_NONE)
ASSERT3U(cvd->vdev_ashift, ==, spa->spa_max_ashift);
if (!vdev_is_concrete(cvd))
continue;
if (vdev_get_nparity(cvd) != 0)
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;
boolean_t set_noalloc = B_FALSE;
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);
/*
* 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.
*/
if (error == 0 && !vd->vdev_noalloc) {
set_noalloc = B_TRUE;
error = vdev_passivate(vd, txg);
}
if (error != 0)
return (error);
/*
* 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.
*/
spa_vdev_config_exit(spa, NULL, *txg, 0, FTAG);
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.
*/
error = spa_vdev_remove_top_check(vd);
if (error != 0) {
if (set_noalloc)
vdev_activate(vd);
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, 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;
const char *vd_type = NULL;
char *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) {
const char *type;
boolean_t draid_spare = B_FALSE;
if (nvlist_lookup_string(nv, ZPOOL_CONFIG_TYPE, &type)
== 0 && strcmp(type, VDEV_TYPE_DRAID_SPARE) == 0)
draid_spare = B_TRUE;
if (vd == NULL && draid_spare) {
error = SET_ERROR(ENOTSUP);
} else {
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);
}
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, UINT, ZMOD_RW,
"Largest contiguous segment to allocate when removing device");
ZFS_MODULE_PARAM(zfs_vdev, vdev_, removal_max_span, UINT, ZMOD_RW,
"Largest span of free chunks a remap segment can span");
/* BEGIN CSTYLED */
ZFS_MODULE_PARAM(zfs_vdev, zfs_, removal_suspend_progress, UINT, 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);
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