+++ /dev/null
-/*
- * CDDL HEADER START
- *
- * The contents of this file are subject to the terms of the
- * Common Development and Distribution License (the "License").
- * You may not use this file except in compliance with the License.
- *
- * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
- * or http://www.opensolaris.org/os/licensing.
- * See the License for the specific language governing permissions
- * and limitations under the License.
- *
- * When distributing Covered Code, include this CDDL HEADER in each
- * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
- * If applicable, add the following below this CDDL HEADER, with the
- * fields enclosed by brackets "[]" replaced with your own identifying
- * information: Portions Copyright [yyyy] [name of copyright owner]
- *
- * CDDL HEADER END
- */
-/*
- * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2011, 2017 by Delphix. All rights reserved.
- * Copyright (c) 2013 Steven Hartland. All rights reserved.
- * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
- * Copyright 2016 Nexenta Systems, Inc. All rights reserved.
- */
-
-#include <sys/dsl_pool.h>
-#include <sys/dsl_dataset.h>
-#include <sys/dsl_prop.h>
-#include <sys/dsl_dir.h>
-#include <sys/dsl_synctask.h>
-#include <sys/dsl_scan.h>
-#include <sys/dnode.h>
-#include <sys/dmu_tx.h>
-#include <sys/dmu_objset.h>
-#include <sys/arc.h>
-#include <sys/zap.h>
-#include <sys/zio.h>
-#include <sys/zfs_context.h>
-#include <sys/fs/zfs.h>
-#include <sys/zfs_znode.h>
-#include <sys/spa_impl.h>
-#include <sys/dsl_deadlist.h>
-#include <sys/bptree.h>
-#include <sys/zfeature.h>
-#include <sys/zil_impl.h>
-#include <sys/dsl_userhold.h>
-#include <sys/trace_txg.h>
-#include <sys/mmp.h>
-
-/*
- * ZFS Write Throttle
- * ------------------
- *
- * ZFS must limit the rate of incoming writes to the rate at which it is able
- * to sync data modifications to the backend storage. Throttling by too much
- * creates an artificial limit; throttling by too little can only be sustained
- * for short periods and would lead to highly lumpy performance. On a per-pool
- * basis, ZFS tracks the amount of modified (dirty) data. As operations change
- * data, the amount of dirty data increases; as ZFS syncs out data, the amount
- * of dirty data decreases. When the amount of dirty data exceeds a
- * predetermined threshold further modifications are blocked until the amount
- * of dirty data decreases (as data is synced out).
- *
- * The limit on dirty data is tunable, and should be adjusted according to
- * both the IO capacity and available memory of the system. The larger the
- * window, the more ZFS is able to aggregate and amortize metadata (and data)
- * changes. However, memory is a limited resource, and allowing for more dirty
- * data comes at the cost of keeping other useful data in memory (for example
- * ZFS data cached by the ARC).
- *
- * Implementation
- *
- * As buffers are modified dsl_pool_willuse_space() increments both the per-
- * txg (dp_dirty_pertxg[]) and poolwide (dp_dirty_total) accounting of
- * dirty space used; dsl_pool_dirty_space() decrements those values as data
- * is synced out from dsl_pool_sync(). While only the poolwide value is
- * relevant, the per-txg value is useful for debugging. The tunable
- * zfs_dirty_data_max determines the dirty space limit. Once that value is
- * exceeded, new writes are halted until space frees up.
- *
- * The zfs_dirty_data_sync tunable dictates the threshold at which we
- * ensure that there is a txg syncing (see the comment in txg.c for a full
- * description of transaction group stages).
- *
- * The IO scheduler uses both the dirty space limit and current amount of
- * dirty data as inputs. Those values affect the number of concurrent IOs ZFS
- * issues. See the comment in vdev_queue.c for details of the IO scheduler.
- *
- * The delay is also calculated based on the amount of dirty data. See the
- * comment above dmu_tx_delay() for details.
- */
-
-/*
- * zfs_dirty_data_max will be set to zfs_dirty_data_max_percent% of all memory,
- * capped at zfs_dirty_data_max_max. It can also be overridden with a module
- * parameter.
- */
-unsigned long zfs_dirty_data_max = 0;
-unsigned long zfs_dirty_data_max_max = 0;
-int zfs_dirty_data_max_percent = 10;
-int zfs_dirty_data_max_max_percent = 25;
-
-/*
- * If there is at least this much dirty data, push out a txg.
- */
-unsigned long zfs_dirty_data_sync = 64 * 1024 * 1024;
-
-/*
- * Once there is this amount of dirty data, the dmu_tx_delay() will kick in
- * and delay each transaction.
- * This value should be >= zfs_vdev_async_write_active_max_dirty_percent.
- */
-int zfs_delay_min_dirty_percent = 60;
-
-/*
- * This controls how quickly the delay approaches infinity.
- * Larger values cause it to delay more for a given amount of dirty data.
- * Therefore larger values will cause there to be less dirty data for a
- * given throughput.
- *
- * For the smoothest delay, this value should be about 1 billion divided
- * by the maximum number of operations per second. This will smoothly
- * handle between 10x and 1/10th this number.
- *
- * Note: zfs_delay_scale * zfs_dirty_data_max must be < 2^64, due to the
- * multiply in dmu_tx_delay().
- */
-unsigned long zfs_delay_scale = 1000 * 1000 * 1000 / 2000;
-
-/*
- * This determines the number of threads used by the dp_sync_taskq.
- */
-int zfs_sync_taskq_batch_pct = 75;
-
-/*
- * These tunables determine the behavior of how zil_itxg_clean() is
- * called via zil_clean() in the context of spa_sync(). When an itxg
- * list needs to be cleaned, TQ_NOSLEEP will be used when dispatching.
- * If the dispatch fails, the call to zil_itxg_clean() will occur
- * synchronously in the context of spa_sync(), which can negatively
- * impact the performance of spa_sync() (e.g. in the case of the itxg
- * list having a large number of itxs that needs to be cleaned).
- *
- * Thus, these tunables can be used to manipulate the behavior of the
- * taskq used by zil_clean(); they determine the number of taskq entries
- * that are pre-populated when the taskq is first created (via the
- * "zfs_zil_clean_taskq_minalloc" tunable) and the maximum number of
- * taskq entries that are cached after an on-demand allocation (via the
- * "zfs_zil_clean_taskq_maxalloc").
- *
- * The idea being, we want to try reasonably hard to ensure there will
- * already be a taskq entry pre-allocated by the time that it is needed
- * by zil_clean(). This way, we can avoid the possibility of an
- * on-demand allocation of a new taskq entry from failing, which would
- * result in zil_itxg_clean() being called synchronously from zil_clean()
- * (which can adversely affect performance of spa_sync()).
- *
- * Additionally, the number of threads used by the taskq can be
- * configured via the "zfs_zil_clean_taskq_nthr_pct" tunable.
- */
-int zfs_zil_clean_taskq_nthr_pct = 100;
-int zfs_zil_clean_taskq_minalloc = 1024;
-int zfs_zil_clean_taskq_maxalloc = 1024 * 1024;
-
-int
-dsl_pool_open_special_dir(dsl_pool_t *dp, const char *name, dsl_dir_t **ddp)
-{
- uint64_t obj;
- int err;
-
- err = zap_lookup(dp->dp_meta_objset,
- dsl_dir_phys(dp->dp_root_dir)->dd_child_dir_zapobj,
- name, sizeof (obj), 1, &obj);
- if (err)
- return (err);
-
- return (dsl_dir_hold_obj(dp, obj, name, dp, ddp));
-}
-
-static dsl_pool_t *
-dsl_pool_open_impl(spa_t *spa, uint64_t txg)
-{
- dsl_pool_t *dp;
- blkptr_t *bp = spa_get_rootblkptr(spa);
-
- dp = kmem_zalloc(sizeof (dsl_pool_t), KM_SLEEP);
- dp->dp_spa = spa;
- dp->dp_meta_rootbp = *bp;
- rrw_init(&dp->dp_config_rwlock, B_TRUE);
- txg_init(dp, txg);
- mmp_init(spa);
-
- txg_list_create(&dp->dp_dirty_datasets, spa,
- offsetof(dsl_dataset_t, ds_dirty_link));
- txg_list_create(&dp->dp_dirty_zilogs, spa,
- offsetof(zilog_t, zl_dirty_link));
- txg_list_create(&dp->dp_dirty_dirs, spa,
- offsetof(dsl_dir_t, dd_dirty_link));
- txg_list_create(&dp->dp_sync_tasks, spa,
- offsetof(dsl_sync_task_t, dst_node));
-
- dp->dp_sync_taskq = taskq_create("dp_sync_taskq",
- zfs_sync_taskq_batch_pct, minclsyspri, 1, INT_MAX,
- TASKQ_THREADS_CPU_PCT);
-
- dp->dp_zil_clean_taskq = taskq_create("dp_zil_clean_taskq",
- zfs_zil_clean_taskq_nthr_pct, minclsyspri,
- zfs_zil_clean_taskq_minalloc,
- zfs_zil_clean_taskq_maxalloc,
- TASKQ_PREPOPULATE | TASKQ_THREADS_CPU_PCT);
-
- mutex_init(&dp->dp_lock, NULL, MUTEX_DEFAULT, NULL);
- cv_init(&dp->dp_spaceavail_cv, NULL, CV_DEFAULT, NULL);
-
- dp->dp_iput_taskq = taskq_create("z_iput", max_ncpus, defclsyspri,
- max_ncpus * 8, INT_MAX, TASKQ_PREPOPULATE | TASKQ_DYNAMIC);
-
- return (dp);
-}
-
-int
-dsl_pool_init(spa_t *spa, uint64_t txg, dsl_pool_t **dpp)
-{
- int err;
- dsl_pool_t *dp = dsl_pool_open_impl(spa, txg);
-
- /*
- * Initialize the caller's dsl_pool_t structure before we actually open
- * the meta objset. This is done because a self-healing write zio may
- * be issued as part of dmu_objset_open_impl() and the spa needs its
- * dsl_pool_t initialized in order to handle the write.
- */
- *dpp = dp;
-
- err = dmu_objset_open_impl(spa, NULL, &dp->dp_meta_rootbp,
- &dp->dp_meta_objset);
- if (err != 0) {
- dsl_pool_close(dp);
- *dpp = NULL;
- }
-
- return (err);
-}
-
-int
-dsl_pool_open(dsl_pool_t *dp)
-{
- int err;
- dsl_dir_t *dd;
- dsl_dataset_t *ds;
- uint64_t obj;
-
- rrw_enter(&dp->dp_config_rwlock, RW_WRITER, FTAG);
- err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
- DMU_POOL_ROOT_DATASET, sizeof (uint64_t), 1,
- &dp->dp_root_dir_obj);
- if (err)
- goto out;
-
- err = dsl_dir_hold_obj(dp, dp->dp_root_dir_obj,
- NULL, dp, &dp->dp_root_dir);
- if (err)
- goto out;
-
- err = dsl_pool_open_special_dir(dp, MOS_DIR_NAME, &dp->dp_mos_dir);
- if (err)
- goto out;
-
- if (spa_version(dp->dp_spa) >= SPA_VERSION_ORIGIN) {
- err = dsl_pool_open_special_dir(dp, ORIGIN_DIR_NAME, &dd);
- if (err)
- goto out;
- err = dsl_dataset_hold_obj(dp,
- dsl_dir_phys(dd)->dd_head_dataset_obj, FTAG, &ds);
- if (err == 0) {
- err = dsl_dataset_hold_obj(dp,
- dsl_dataset_phys(ds)->ds_prev_snap_obj, dp,
- &dp->dp_origin_snap);
- dsl_dataset_rele(ds, FTAG);
- }
- dsl_dir_rele(dd, dp);
- if (err)
- goto out;
- }
-
- if (spa_version(dp->dp_spa) >= SPA_VERSION_DEADLISTS) {
- err = dsl_pool_open_special_dir(dp, FREE_DIR_NAME,
- &dp->dp_free_dir);
- if (err)
- goto out;
-
- err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
- DMU_POOL_FREE_BPOBJ, sizeof (uint64_t), 1, &obj);
- if (err)
- goto out;
- VERIFY0(bpobj_open(&dp->dp_free_bpobj,
- dp->dp_meta_objset, obj));
- }
-
- /*
- * Note: errors ignored, because the leak dir will not exist if we
- * have not encountered a leak yet.
- */
- (void) dsl_pool_open_special_dir(dp, LEAK_DIR_NAME,
- &dp->dp_leak_dir);
-
- if (spa_feature_is_active(dp->dp_spa, SPA_FEATURE_ASYNC_DESTROY)) {
- err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
- DMU_POOL_BPTREE_OBJ, sizeof (uint64_t), 1,
- &dp->dp_bptree_obj);
- if (err != 0)
- goto out;
- }
-
- if (spa_feature_is_active(dp->dp_spa, SPA_FEATURE_EMPTY_BPOBJ)) {
- err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
- DMU_POOL_EMPTY_BPOBJ, sizeof (uint64_t), 1,
- &dp->dp_empty_bpobj);
- if (err != 0)
- goto out;
- }
-
- err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
- DMU_POOL_TMP_USERREFS, sizeof (uint64_t), 1,
- &dp->dp_tmp_userrefs_obj);
- if (err == ENOENT)
- err = 0;
- if (err)
- goto out;
-
- err = dsl_scan_init(dp, dp->dp_tx.tx_open_txg);
-
-out:
- rrw_exit(&dp->dp_config_rwlock, FTAG);
- return (err);
-}
-
-void
-dsl_pool_close(dsl_pool_t *dp)
-{
- /*
- * Drop our references from dsl_pool_open().
- *
- * Since we held the origin_snap from "syncing" context (which
- * includes pool-opening context), it actually only got a "ref"
- * and not a hold, so just drop that here.
- */
- if (dp->dp_origin_snap)
- dsl_dataset_rele(dp->dp_origin_snap, dp);
- if (dp->dp_mos_dir)
- dsl_dir_rele(dp->dp_mos_dir, dp);
- if (dp->dp_free_dir)
- dsl_dir_rele(dp->dp_free_dir, dp);
- if (dp->dp_leak_dir)
- dsl_dir_rele(dp->dp_leak_dir, dp);
- if (dp->dp_root_dir)
- dsl_dir_rele(dp->dp_root_dir, dp);
-
- bpobj_close(&dp->dp_free_bpobj);
-
- /* undo the dmu_objset_open_impl(mos) from dsl_pool_open() */
- if (dp->dp_meta_objset)
- dmu_objset_evict(dp->dp_meta_objset);
-
- txg_list_destroy(&dp->dp_dirty_datasets);
- txg_list_destroy(&dp->dp_dirty_zilogs);
- txg_list_destroy(&dp->dp_sync_tasks);
- txg_list_destroy(&dp->dp_dirty_dirs);
-
- taskq_destroy(dp->dp_zil_clean_taskq);
- taskq_destroy(dp->dp_sync_taskq);
-
- /*
- * We can't set retry to TRUE since we're explicitly specifying
- * a spa to flush. This is good enough; any missed buffers for
- * this spa won't cause trouble, and they'll eventually fall
- * out of the ARC just like any other unused buffer.
- */
- arc_flush(dp->dp_spa, FALSE);
-
- mmp_fini(dp->dp_spa);
- txg_fini(dp);
- dsl_scan_fini(dp);
- dmu_buf_user_evict_wait();
-
- rrw_destroy(&dp->dp_config_rwlock);
- mutex_destroy(&dp->dp_lock);
- cv_destroy(&dp->dp_spaceavail_cv);
- taskq_destroy(dp->dp_iput_taskq);
- if (dp->dp_blkstats)
- vmem_free(dp->dp_blkstats, sizeof (zfs_all_blkstats_t));
- kmem_free(dp, sizeof (dsl_pool_t));
-}
-
-dsl_pool_t *
-dsl_pool_create(spa_t *spa, nvlist_t *zplprops, uint64_t txg)
-{
- int err;
- dsl_pool_t *dp = dsl_pool_open_impl(spa, txg);
- dmu_tx_t *tx = dmu_tx_create_assigned(dp, txg);
- objset_t *os;
- dsl_dataset_t *ds;
- uint64_t obj;
-
- rrw_enter(&dp->dp_config_rwlock, RW_WRITER, FTAG);
-
- /* create and open the MOS (meta-objset) */
- dp->dp_meta_objset = dmu_objset_create_impl(spa,
- NULL, &dp->dp_meta_rootbp, DMU_OST_META, tx);
-
- /* create the pool directory */
- err = zap_create_claim(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
- DMU_OT_OBJECT_DIRECTORY, DMU_OT_NONE, 0, tx);
- ASSERT0(err);
-
- /* Initialize scan structures */
- VERIFY0(dsl_scan_init(dp, txg));
-
- /* create and open the root dir */
- dp->dp_root_dir_obj = dsl_dir_create_sync(dp, NULL, NULL, tx);
- VERIFY0(dsl_dir_hold_obj(dp, dp->dp_root_dir_obj,
- NULL, dp, &dp->dp_root_dir));
-
- /* create and open the meta-objset dir */
- (void) dsl_dir_create_sync(dp, dp->dp_root_dir, MOS_DIR_NAME, tx);
- VERIFY0(dsl_pool_open_special_dir(dp,
- MOS_DIR_NAME, &dp->dp_mos_dir));
-
- if (spa_version(spa) >= SPA_VERSION_DEADLISTS) {
- /* create and open the free dir */
- (void) dsl_dir_create_sync(dp, dp->dp_root_dir,
- FREE_DIR_NAME, tx);
- VERIFY0(dsl_pool_open_special_dir(dp,
- FREE_DIR_NAME, &dp->dp_free_dir));
-
- /* create and open the free_bplist */
- obj = bpobj_alloc(dp->dp_meta_objset, SPA_OLD_MAXBLOCKSIZE, tx);
- VERIFY(zap_add(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
- DMU_POOL_FREE_BPOBJ, sizeof (uint64_t), 1, &obj, tx) == 0);
- VERIFY0(bpobj_open(&dp->dp_free_bpobj,
- dp->dp_meta_objset, obj));
- }
-
- if (spa_version(spa) >= SPA_VERSION_DSL_SCRUB)
- dsl_pool_create_origin(dp, tx);
-
- /* create the root dataset */
- obj = dsl_dataset_create_sync_dd(dp->dp_root_dir, NULL, 0, tx);
-
- /* create the root objset */
- VERIFY0(dsl_dataset_hold_obj(dp, obj, FTAG, &ds));
- rrw_enter(&ds->ds_bp_rwlock, RW_READER, FTAG);
- VERIFY(NULL != (os = dmu_objset_create_impl(dp->dp_spa, ds,
- dsl_dataset_get_blkptr(ds), DMU_OST_ZFS, tx)));
- rrw_exit(&ds->ds_bp_rwlock, FTAG);
-#ifdef _KERNEL
- zfs_create_fs(os, kcred, zplprops, tx);
-#endif
- dsl_dataset_rele(ds, FTAG);
-
- dmu_tx_commit(tx);
-
- rrw_exit(&dp->dp_config_rwlock, FTAG);
-
- return (dp);
-}
-
-/*
- * Account for the meta-objset space in its placeholder dsl_dir.
- */
-void
-dsl_pool_mos_diduse_space(dsl_pool_t *dp,
- int64_t used, int64_t comp, int64_t uncomp)
-{
- ASSERT3U(comp, ==, uncomp); /* it's all metadata */
- mutex_enter(&dp->dp_lock);
- dp->dp_mos_used_delta += used;
- dp->dp_mos_compressed_delta += comp;
- dp->dp_mos_uncompressed_delta += uncomp;
- mutex_exit(&dp->dp_lock);
-}
-
-static void
-dsl_pool_sync_mos(dsl_pool_t *dp, dmu_tx_t *tx)
-{
- zio_t *zio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
- dmu_objset_sync(dp->dp_meta_objset, zio, tx);
- VERIFY0(zio_wait(zio));
- dprintf_bp(&dp->dp_meta_rootbp, "meta objset rootbp is %s", "");
- spa_set_rootblkptr(dp->dp_spa, &dp->dp_meta_rootbp);
-}
-
-static void
-dsl_pool_dirty_delta(dsl_pool_t *dp, int64_t delta)
-{
- ASSERT(MUTEX_HELD(&dp->dp_lock));
-
- if (delta < 0)
- ASSERT3U(-delta, <=, dp->dp_dirty_total);
-
- dp->dp_dirty_total += delta;
-
- /*
- * Note: we signal even when increasing dp_dirty_total.
- * This ensures forward progress -- each thread wakes the next waiter.
- */
- if (dp->dp_dirty_total < zfs_dirty_data_max)
- cv_signal(&dp->dp_spaceavail_cv);
-}
-
-void
-dsl_pool_sync(dsl_pool_t *dp, uint64_t txg)
-{
- zio_t *zio;
- dmu_tx_t *tx;
- dsl_dir_t *dd;
- dsl_dataset_t *ds;
- objset_t *mos = dp->dp_meta_objset;
- list_t synced_datasets;
-
- list_create(&synced_datasets, sizeof (dsl_dataset_t),
- offsetof(dsl_dataset_t, ds_synced_link));
-
- tx = dmu_tx_create_assigned(dp, txg);
-
- /*
- * Write out all dirty blocks of dirty datasets.
- */
- zio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
- while ((ds = txg_list_remove(&dp->dp_dirty_datasets, txg)) != NULL) {
- /*
- * We must not sync any non-MOS datasets twice, because
- * we may have taken a snapshot of them. However, we
- * may sync newly-created datasets on pass 2.
- */
- ASSERT(!list_link_active(&ds->ds_synced_link));
- list_insert_tail(&synced_datasets, ds);
- dsl_dataset_sync(ds, zio, tx);
- }
- VERIFY0(zio_wait(zio));
-
- /*
- * We have written all of the accounted dirty data, so our
- * dp_space_towrite should now be zero. However, some seldom-used
- * code paths do not adhere to this (e.g. dbuf_undirty(), also
- * rounding error in dbuf_write_physdone).
- * Shore up the accounting of any dirtied space now.
- */
- dsl_pool_undirty_space(dp, dp->dp_dirty_pertxg[txg & TXG_MASK], txg);
-
- /*
- * Update the long range free counter after
- * we're done syncing user data
- */
- mutex_enter(&dp->dp_lock);
- ASSERT(spa_sync_pass(dp->dp_spa) == 1 ||
- dp->dp_long_free_dirty_pertxg[txg & TXG_MASK] == 0);
- dp->dp_long_free_dirty_pertxg[txg & TXG_MASK] = 0;
- mutex_exit(&dp->dp_lock);
-
- /*
- * After the data blocks have been written (ensured by the zio_wait()
- * above), update the user/group space accounting. This happens
- * in tasks dispatched to dp_sync_taskq, so wait for them before
- * continuing.
- */
- for (ds = list_head(&synced_datasets); ds != NULL;
- ds = list_next(&synced_datasets, ds)) {
- dmu_objset_do_userquota_updates(ds->ds_objset, tx);
- }
- taskq_wait(dp->dp_sync_taskq);
-
- /*
- * Sync the datasets again to push out the changes due to
- * userspace updates. This must be done before we process the
- * sync tasks, so that any snapshots will have the correct
- * user accounting information (and we won't get confused
- * about which blocks are part of the snapshot).
- */
- zio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
- while ((ds = txg_list_remove(&dp->dp_dirty_datasets, txg)) != NULL) {
- ASSERT(list_link_active(&ds->ds_synced_link));
- dmu_buf_rele(ds->ds_dbuf, ds);
- dsl_dataset_sync(ds, zio, tx);
- }
- VERIFY0(zio_wait(zio));
-
- /*
- * Now that the datasets have been completely synced, we can
- * clean up our in-memory structures accumulated while syncing:
- *
- * - move dead blocks from the pending deadlist to the on-disk deadlist
- * - release hold from dsl_dataset_dirty()
- */
- while ((ds = list_remove_head(&synced_datasets)) != NULL) {
- dsl_dataset_sync_done(ds, tx);
- }
-
- while ((dd = txg_list_remove(&dp->dp_dirty_dirs, txg)) != NULL) {
- dsl_dir_sync(dd, tx);
- }
-
- /*
- * The MOS's space is accounted for in the pool/$MOS
- * (dp_mos_dir). We can't modify the mos while we're syncing
- * it, so we remember the deltas and apply them here.
- */
- if (dp->dp_mos_used_delta != 0 || dp->dp_mos_compressed_delta != 0 ||
- dp->dp_mos_uncompressed_delta != 0) {
- dsl_dir_diduse_space(dp->dp_mos_dir, DD_USED_HEAD,
- dp->dp_mos_used_delta,
- dp->dp_mos_compressed_delta,
- dp->dp_mos_uncompressed_delta, tx);
- dp->dp_mos_used_delta = 0;
- dp->dp_mos_compressed_delta = 0;
- dp->dp_mos_uncompressed_delta = 0;
- }
-
- if (!multilist_is_empty(mos->os_dirty_dnodes[txg & TXG_MASK])) {
- dsl_pool_sync_mos(dp, tx);
- }
-
- /*
- * If we modify a dataset in the same txg that we want to destroy it,
- * its dsl_dir's dd_dbuf will be dirty, and thus have a hold on it.
- * dsl_dir_destroy_check() will fail if there are unexpected holds.
- * Therefore, we want to sync the MOS (thus syncing the dd_dbuf
- * and clearing the hold on it) before we process the sync_tasks.
- * The MOS data dirtied by the sync_tasks will be synced on the next
- * pass.
- */
- if (!txg_list_empty(&dp->dp_sync_tasks, txg)) {
- dsl_sync_task_t *dst;
- /*
- * No more sync tasks should have been added while we
- * were syncing.
- */
- ASSERT3U(spa_sync_pass(dp->dp_spa), ==, 1);
- while ((dst = txg_list_remove(&dp->dp_sync_tasks, txg)) != NULL)
- dsl_sync_task_sync(dst, tx);
- }
-
- dmu_tx_commit(tx);
-
- DTRACE_PROBE2(dsl_pool_sync__done, dsl_pool_t *dp, dp, uint64_t, txg);
-}
-
-void
-dsl_pool_sync_done(dsl_pool_t *dp, uint64_t txg)
-{
- zilog_t *zilog;
-
- while ((zilog = txg_list_head(&dp->dp_dirty_zilogs, txg))) {
- dsl_dataset_t *ds = dmu_objset_ds(zilog->zl_os);
- /*
- * We don't remove the zilog from the dp_dirty_zilogs
- * list until after we've cleaned it. This ensures that
- * callers of zilog_is_dirty() receive an accurate
- * answer when they are racing with the spa sync thread.
- */
- zil_clean(zilog, txg);
- (void) txg_list_remove_this(&dp->dp_dirty_zilogs, zilog, txg);
- ASSERT(!dmu_objset_is_dirty(zilog->zl_os, txg));
- dmu_buf_rele(ds->ds_dbuf, zilog);
- }
- ASSERT(!dmu_objset_is_dirty(dp->dp_meta_objset, txg));
-}
-
-/*
- * TRUE if the current thread is the tx_sync_thread or if we
- * are being called from SPA context during pool initialization.
- */
-int
-dsl_pool_sync_context(dsl_pool_t *dp)
-{
- return (curthread == dp->dp_tx.tx_sync_thread ||
- spa_is_initializing(dp->dp_spa) ||
- taskq_member(dp->dp_sync_taskq, curthread));
-}
-
-uint64_t
-dsl_pool_adjustedsize(dsl_pool_t *dp, boolean_t netfree)
-{
- uint64_t space, resv;
-
- /*
- * If we're trying to assess whether it's OK to do a free,
- * cut the reservation in half to allow forward progress
- * (e.g. make it possible to rm(1) files from a full pool).
- */
- space = spa_get_dspace(dp->dp_spa);
- resv = spa_get_slop_space(dp->dp_spa);
- if (netfree)
- resv >>= 1;
-
- return (space - resv);
-}
-
-boolean_t
-dsl_pool_need_dirty_delay(dsl_pool_t *dp)
-{
- uint64_t delay_min_bytes =
- zfs_dirty_data_max * zfs_delay_min_dirty_percent / 100;
- boolean_t rv;
-
- mutex_enter(&dp->dp_lock);
- if (dp->dp_dirty_total > zfs_dirty_data_sync)
- txg_kick(dp);
- rv = (dp->dp_dirty_total > delay_min_bytes);
- mutex_exit(&dp->dp_lock);
- return (rv);
-}
-
-void
-dsl_pool_dirty_space(dsl_pool_t *dp, int64_t space, dmu_tx_t *tx)
-{
- if (space > 0) {
- mutex_enter(&dp->dp_lock);
- dp->dp_dirty_pertxg[tx->tx_txg & TXG_MASK] += space;
- dsl_pool_dirty_delta(dp, space);
- mutex_exit(&dp->dp_lock);
- }
-}
-
-void
-dsl_pool_undirty_space(dsl_pool_t *dp, int64_t space, uint64_t txg)
-{
- ASSERT3S(space, >=, 0);
- if (space == 0)
- return;
-
- mutex_enter(&dp->dp_lock);
- if (dp->dp_dirty_pertxg[txg & TXG_MASK] < space) {
- /* XXX writing something we didn't dirty? */
- space = dp->dp_dirty_pertxg[txg & TXG_MASK];
- }
- ASSERT3U(dp->dp_dirty_pertxg[txg & TXG_MASK], >=, space);
- dp->dp_dirty_pertxg[txg & TXG_MASK] -= space;
- ASSERT3U(dp->dp_dirty_total, >=, space);
- dsl_pool_dirty_delta(dp, -space);
- mutex_exit(&dp->dp_lock);
-}
-
-/* ARGSUSED */
-static int
-upgrade_clones_cb(dsl_pool_t *dp, dsl_dataset_t *hds, void *arg)
-{
- dmu_tx_t *tx = arg;
- dsl_dataset_t *ds, *prev = NULL;
- int err;
-
- err = dsl_dataset_hold_obj(dp, hds->ds_object, FTAG, &ds);
- if (err)
- return (err);
-
- while (dsl_dataset_phys(ds)->ds_prev_snap_obj != 0) {
- err = dsl_dataset_hold_obj(dp,
- dsl_dataset_phys(ds)->ds_prev_snap_obj, FTAG, &prev);
- if (err) {
- dsl_dataset_rele(ds, FTAG);
- return (err);
- }
-
- if (dsl_dataset_phys(prev)->ds_next_snap_obj != ds->ds_object)
- break;
- dsl_dataset_rele(ds, FTAG);
- ds = prev;
- prev = NULL;
- }
-
- if (prev == NULL) {
- prev = dp->dp_origin_snap;
-
- /*
- * The $ORIGIN can't have any data, or the accounting
- * will be wrong.
- */
- rrw_enter(&ds->ds_bp_rwlock, RW_READER, FTAG);
- ASSERT0(dsl_dataset_phys(prev)->ds_bp.blk_birth);
- rrw_exit(&ds->ds_bp_rwlock, FTAG);
-
- /* The origin doesn't get attached to itself */
- if (ds->ds_object == prev->ds_object) {
- dsl_dataset_rele(ds, FTAG);
- return (0);
- }
-
- dmu_buf_will_dirty(ds->ds_dbuf, tx);
- dsl_dataset_phys(ds)->ds_prev_snap_obj = prev->ds_object;
- dsl_dataset_phys(ds)->ds_prev_snap_txg =
- dsl_dataset_phys(prev)->ds_creation_txg;
-
- dmu_buf_will_dirty(ds->ds_dir->dd_dbuf, tx);
- dsl_dir_phys(ds->ds_dir)->dd_origin_obj = prev->ds_object;
-
- dmu_buf_will_dirty(prev->ds_dbuf, tx);
- dsl_dataset_phys(prev)->ds_num_children++;
-
- if (dsl_dataset_phys(ds)->ds_next_snap_obj == 0) {
- ASSERT(ds->ds_prev == NULL);
- VERIFY0(dsl_dataset_hold_obj(dp,
- dsl_dataset_phys(ds)->ds_prev_snap_obj,
- ds, &ds->ds_prev));
- }
- }
-
- ASSERT3U(dsl_dir_phys(ds->ds_dir)->dd_origin_obj, ==, prev->ds_object);
- ASSERT3U(dsl_dataset_phys(ds)->ds_prev_snap_obj, ==, prev->ds_object);
-
- if (dsl_dataset_phys(prev)->ds_next_clones_obj == 0) {
- dmu_buf_will_dirty(prev->ds_dbuf, tx);
- dsl_dataset_phys(prev)->ds_next_clones_obj =
- zap_create(dp->dp_meta_objset,
- DMU_OT_NEXT_CLONES, DMU_OT_NONE, 0, tx);
- }
- VERIFY0(zap_add_int(dp->dp_meta_objset,
- dsl_dataset_phys(prev)->ds_next_clones_obj, ds->ds_object, tx));
-
- dsl_dataset_rele(ds, FTAG);
- if (prev != dp->dp_origin_snap)
- dsl_dataset_rele(prev, FTAG);
- return (0);
-}
-
-void
-dsl_pool_upgrade_clones(dsl_pool_t *dp, dmu_tx_t *tx)
-{
- ASSERT(dmu_tx_is_syncing(tx));
- ASSERT(dp->dp_origin_snap != NULL);
-
- VERIFY0(dmu_objset_find_dp(dp, dp->dp_root_dir_obj, upgrade_clones_cb,
- tx, DS_FIND_CHILDREN | DS_FIND_SERIALIZE));
-}
-
-/* ARGSUSED */
-static int
-upgrade_dir_clones_cb(dsl_pool_t *dp, dsl_dataset_t *ds, void *arg)
-{
- dmu_tx_t *tx = arg;
- objset_t *mos = dp->dp_meta_objset;
-
- if (dsl_dir_phys(ds->ds_dir)->dd_origin_obj != 0) {
- dsl_dataset_t *origin;
-
- VERIFY0(dsl_dataset_hold_obj(dp,
- dsl_dir_phys(ds->ds_dir)->dd_origin_obj, FTAG, &origin));
-
- if (dsl_dir_phys(origin->ds_dir)->dd_clones == 0) {
- dmu_buf_will_dirty(origin->ds_dir->dd_dbuf, tx);
- dsl_dir_phys(origin->ds_dir)->dd_clones =
- zap_create(mos, DMU_OT_DSL_CLONES, DMU_OT_NONE,
- 0, tx);
- }
-
- VERIFY0(zap_add_int(dp->dp_meta_objset,
- dsl_dir_phys(origin->ds_dir)->dd_clones,
- ds->ds_object, tx));
-
- dsl_dataset_rele(origin, FTAG);
- }
- return (0);
-}
-
-void
-dsl_pool_upgrade_dir_clones(dsl_pool_t *dp, dmu_tx_t *tx)
-{
- uint64_t obj;
-
- ASSERT(dmu_tx_is_syncing(tx));
-
- (void) dsl_dir_create_sync(dp, dp->dp_root_dir, FREE_DIR_NAME, tx);
- VERIFY0(dsl_pool_open_special_dir(dp,
- FREE_DIR_NAME, &dp->dp_free_dir));
-
- /*
- * We can't use bpobj_alloc(), because spa_version() still
- * returns the old version, and we need a new-version bpobj with
- * subobj support. So call dmu_object_alloc() directly.
- */
- obj = dmu_object_alloc(dp->dp_meta_objset, DMU_OT_BPOBJ,
- SPA_OLD_MAXBLOCKSIZE, DMU_OT_BPOBJ_HDR, sizeof (bpobj_phys_t), tx);
- VERIFY0(zap_add(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
- DMU_POOL_FREE_BPOBJ, sizeof (uint64_t), 1, &obj, tx));
- VERIFY0(bpobj_open(&dp->dp_free_bpobj, dp->dp_meta_objset, obj));
-
- VERIFY0(dmu_objset_find_dp(dp, dp->dp_root_dir_obj,
- upgrade_dir_clones_cb, tx, DS_FIND_CHILDREN | DS_FIND_SERIALIZE));
-}
-
-void
-dsl_pool_create_origin(dsl_pool_t *dp, dmu_tx_t *tx)
-{
- uint64_t dsobj;
- dsl_dataset_t *ds;
-
- ASSERT(dmu_tx_is_syncing(tx));
- ASSERT(dp->dp_origin_snap == NULL);
- ASSERT(rrw_held(&dp->dp_config_rwlock, RW_WRITER));
-
- /* create the origin dir, ds, & snap-ds */
- dsobj = dsl_dataset_create_sync(dp->dp_root_dir, ORIGIN_DIR_NAME,
- NULL, 0, kcred, tx);
- VERIFY0(dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds));
- dsl_dataset_snapshot_sync_impl(ds, ORIGIN_DIR_NAME, tx);
- VERIFY0(dsl_dataset_hold_obj(dp, dsl_dataset_phys(ds)->ds_prev_snap_obj,
- dp, &dp->dp_origin_snap));
- dsl_dataset_rele(ds, FTAG);
-}
-
-taskq_t *
-dsl_pool_iput_taskq(dsl_pool_t *dp)
-{
- return (dp->dp_iput_taskq);
-}
-
-/*
- * Walk through the pool-wide zap object of temporary snapshot user holds
- * and release them.
- */
-void
-dsl_pool_clean_tmp_userrefs(dsl_pool_t *dp)
-{
- zap_attribute_t za;
- zap_cursor_t zc;
- objset_t *mos = dp->dp_meta_objset;
- uint64_t zapobj = dp->dp_tmp_userrefs_obj;
- nvlist_t *holds;
-
- if (zapobj == 0)
- return;
- ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS);
-
- holds = fnvlist_alloc();
-
- for (zap_cursor_init(&zc, mos, zapobj);
- zap_cursor_retrieve(&zc, &za) == 0;
- zap_cursor_advance(&zc)) {
- char *htag;
- nvlist_t *tags;
-
- htag = strchr(za.za_name, '-');
- *htag = '\0';
- ++htag;
- if (nvlist_lookup_nvlist(holds, za.za_name, &tags) != 0) {
- tags = fnvlist_alloc();
- fnvlist_add_boolean(tags, htag);
- fnvlist_add_nvlist(holds, za.za_name, tags);
- fnvlist_free(tags);
- } else {
- fnvlist_add_boolean(tags, htag);
- }
- }
- dsl_dataset_user_release_tmp(dp, holds);
- fnvlist_free(holds);
- zap_cursor_fini(&zc);
-}
-
-/*
- * Create the pool-wide zap object for storing temporary snapshot holds.
- */
-void
-dsl_pool_user_hold_create_obj(dsl_pool_t *dp, dmu_tx_t *tx)
-{
- objset_t *mos = dp->dp_meta_objset;
-
- ASSERT(dp->dp_tmp_userrefs_obj == 0);
- ASSERT(dmu_tx_is_syncing(tx));
-
- dp->dp_tmp_userrefs_obj = zap_create_link(mos, DMU_OT_USERREFS,
- DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_TMP_USERREFS, tx);
-}
-
-static int
-dsl_pool_user_hold_rele_impl(dsl_pool_t *dp, uint64_t dsobj,
- const char *tag, uint64_t now, dmu_tx_t *tx, boolean_t holding)
-{
- objset_t *mos = dp->dp_meta_objset;
- uint64_t zapobj = dp->dp_tmp_userrefs_obj;
- char *name;
- int error;
-
- ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS);
- ASSERT(dmu_tx_is_syncing(tx));
-
- /*
- * If the pool was created prior to SPA_VERSION_USERREFS, the
- * zap object for temporary holds might not exist yet.
- */
- if (zapobj == 0) {
- if (holding) {
- dsl_pool_user_hold_create_obj(dp, tx);
- zapobj = dp->dp_tmp_userrefs_obj;
- } else {
- return (SET_ERROR(ENOENT));
- }
- }
-
- name = kmem_asprintf("%llx-%s", (u_longlong_t)dsobj, tag);
- if (holding)
- error = zap_add(mos, zapobj, name, 8, 1, &now, tx);
- else
- error = zap_remove(mos, zapobj, name, tx);
- strfree(name);
-
- return (error);
-}
-
-/*
- * Add a temporary hold for the given dataset object and tag.
- */
-int
-dsl_pool_user_hold(dsl_pool_t *dp, uint64_t dsobj, const char *tag,
- uint64_t now, dmu_tx_t *tx)
-{
- return (dsl_pool_user_hold_rele_impl(dp, dsobj, tag, now, tx, B_TRUE));
-}
-
-/*
- * Release a temporary hold for the given dataset object and tag.
- */
-int
-dsl_pool_user_release(dsl_pool_t *dp, uint64_t dsobj, const char *tag,
- dmu_tx_t *tx)
-{
- return (dsl_pool_user_hold_rele_impl(dp, dsobj, tag, 0,
- tx, B_FALSE));
-}
-
-/*
- * DSL Pool Configuration Lock
- *
- * The dp_config_rwlock protects against changes to DSL state (e.g. dataset
- * creation / destruction / rename / property setting). It must be held for
- * read to hold a dataset or dsl_dir. I.e. you must call
- * dsl_pool_config_enter() or dsl_pool_hold() before calling
- * dsl_{dataset,dir}_hold{_obj}. In most circumstances, the dp_config_rwlock
- * must be held continuously until all datasets and dsl_dirs are released.
- *
- * The only exception to this rule is that if a "long hold" is placed on
- * a dataset, then the dp_config_rwlock may be dropped while the dataset
- * is still held. The long hold will prevent the dataset from being
- * destroyed -- the destroy will fail with EBUSY. A long hold can be
- * obtained by calling dsl_dataset_long_hold(), or by "owning" a dataset
- * (by calling dsl_{dataset,objset}_{try}own{_obj}).
- *
- * Legitimate long-holders (including owners) should be long-running, cancelable
- * tasks that should cause "zfs destroy" to fail. This includes DMU
- * consumers (i.e. a ZPL filesystem being mounted or ZVOL being open),
- * "zfs send", and "zfs diff". There are several other long-holders whose
- * uses are suboptimal (e.g. "zfs promote", and zil_suspend()).
- *
- * The usual formula for long-holding would be:
- * dsl_pool_hold()
- * dsl_dataset_hold()
- * ... perform checks ...
- * dsl_dataset_long_hold()
- * dsl_pool_rele()
- * ... perform long-running task ...
- * dsl_dataset_long_rele()
- * dsl_dataset_rele()
- *
- * Note that when the long hold is released, the dataset is still held but
- * the pool is not held. The dataset may change arbitrarily during this time
- * (e.g. it could be destroyed). Therefore you shouldn't do anything to the
- * dataset except release it.
- *
- * User-initiated operations (e.g. ioctls, zfs_ioc_*()) are either read-only
- * or modifying operations.
- *
- * Modifying operations should generally use dsl_sync_task(). The synctask
- * infrastructure enforces proper locking strategy with respect to the
- * dp_config_rwlock. See the comment above dsl_sync_task() for details.
- *
- * Read-only operations will manually hold the pool, then the dataset, obtain
- * information from the dataset, then release the pool and dataset.
- * dmu_objset_{hold,rele}() are convenience routines that also do the pool
- * hold/rele.
- */
-
-int
-dsl_pool_hold(const char *name, void *tag, dsl_pool_t **dp)
-{
- spa_t *spa;
- int error;
-
- error = spa_open(name, &spa, tag);
- if (error == 0) {
- *dp = spa_get_dsl(spa);
- dsl_pool_config_enter(*dp, tag);
- }
- return (error);
-}
-
-void
-dsl_pool_rele(dsl_pool_t *dp, void *tag)
-{
- dsl_pool_config_exit(dp, tag);
- spa_close(dp->dp_spa, tag);
-}
-
-void
-dsl_pool_config_enter(dsl_pool_t *dp, void *tag)
-{
- /*
- * We use a "reentrant" reader-writer lock, but not reentrantly.
- *
- * The rrwlock can (with the track_all flag) track all reading threads,
- * which is very useful for debugging which code path failed to release
- * the lock, and for verifying that the *current* thread does hold
- * the lock.
- *
- * (Unlike a rwlock, which knows that N threads hold it for
- * read, but not *which* threads, so rw_held(RW_READER) returns TRUE
- * if any thread holds it for read, even if this thread doesn't).
- */
- ASSERT(!rrw_held(&dp->dp_config_rwlock, RW_READER));
- rrw_enter(&dp->dp_config_rwlock, RW_READER, tag);
-}
-
-void
-dsl_pool_config_enter_prio(dsl_pool_t *dp, void *tag)
-{
- ASSERT(!rrw_held(&dp->dp_config_rwlock, RW_READER));
- rrw_enter_read_prio(&dp->dp_config_rwlock, tag);
-}
-
-void
-dsl_pool_config_exit(dsl_pool_t *dp, void *tag)
-{
- rrw_exit(&dp->dp_config_rwlock, tag);
-}
-
-boolean_t
-dsl_pool_config_held(dsl_pool_t *dp)
-{
- return (RRW_LOCK_HELD(&dp->dp_config_rwlock));
-}
-
-boolean_t
-dsl_pool_config_held_writer(dsl_pool_t *dp)
-{
- return (RRW_WRITE_HELD(&dp->dp_config_rwlock));
-}
-
-#if defined(_KERNEL) && defined(HAVE_SPL)
-EXPORT_SYMBOL(dsl_pool_config_enter);
-EXPORT_SYMBOL(dsl_pool_config_exit);
-
-/* BEGIN CSTYLED */
-/* zfs_dirty_data_max_percent only applied at module load in arc_init(). */
-module_param(zfs_dirty_data_max_percent, int, 0444);
-MODULE_PARM_DESC(zfs_dirty_data_max_percent, "percent of ram can be dirty");
-
-/* zfs_dirty_data_max_max_percent only applied at module load in arc_init(). */
-module_param(zfs_dirty_data_max_max_percent, int, 0444);
-MODULE_PARM_DESC(zfs_dirty_data_max_max_percent,
- "zfs_dirty_data_max upper bound as % of RAM");
-
-module_param(zfs_delay_min_dirty_percent, int, 0644);
-MODULE_PARM_DESC(zfs_delay_min_dirty_percent, "transaction delay threshold");
-
-module_param(zfs_dirty_data_max, ulong, 0644);
-MODULE_PARM_DESC(zfs_dirty_data_max, "determines the dirty space limit");
-
-/* zfs_dirty_data_max_max only applied at module load in arc_init(). */
-module_param(zfs_dirty_data_max_max, ulong, 0444);
-MODULE_PARM_DESC(zfs_dirty_data_max_max,
- "zfs_dirty_data_max upper bound in bytes");
-
-module_param(zfs_dirty_data_sync, ulong, 0644);
-MODULE_PARM_DESC(zfs_dirty_data_sync, "sync txg when this much dirty data");
-
-module_param(zfs_delay_scale, ulong, 0644);
-MODULE_PARM_DESC(zfs_delay_scale, "how quickly delay approaches infinity");
-
-module_param(zfs_sync_taskq_batch_pct, int, 0644);
-MODULE_PARM_DESC(zfs_sync_taskq_batch_pct,
- "max percent of CPUs that are used to sync dirty data");
-
-module_param(zfs_zil_clean_taskq_nthr_pct, int, 0644);
-MODULE_PARM_DESC(zfs_zil_clean_taskq_nthr_pct,
- "max percent of CPUs that are used per dp_sync_taskq");
-
-module_param(zfs_zil_clean_taskq_minalloc, int, 0644);
-MODULE_PARM_DESC(zfs_zil_clean_taskq_minalloc,
- "number of taskq entries that are pre-populated");
-
-module_param(zfs_zil_clean_taskq_maxalloc, int, 0644);
-MODULE_PARM_DESC(zfs_zil_clean_taskq_maxalloc,
- "max number of taskq entries that are cached");
-
-/* END CSTYLED */
-#endif
projects / mirror_ubuntu-bionic-kernel.git / blobdiff