X-Git-Url: https://git.proxmox.com/?a=blobdiff_plain;f=module%2Fzfs%2Fdsl_pool.c;h=0ef50717c5f85a913e9a897f991ab6a4d27fc7f7;hb=d1d7e2689db9e03f11c069ebc9f1ba12829e5dac;hp=2cd21a102beb10904ae8139993af786167265dcf;hpb=428870ff734fdaccc342b33fc53cf94724409a46;p=mirror_zfs.git diff --git a/module/zfs/dsl_pool.c b/module/zfs/dsl_pool.c index 2cd21a102..0ef50717c 100644 --- a/module/zfs/dsl_pool.c +++ b/module/zfs/dsl_pool.c @@ -20,6 +20,8 @@ */ /* * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2013 by Delphix. All rights reserved. + * Copyright (c) 2013 Steven Hartland. All rights reserved. */ #include @@ -39,19 +41,93 @@ #include #include #include +#include +#include +#include +#include -int zfs_no_write_throttle = 0; -int zfs_write_limit_shift = 3; /* 1/8th of physical memory */ -int zfs_txg_synctime_ms = 5000; /* target millisecs to sync a txg */ +/* + * 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; -uint64_t zfs_write_limit_min = 32 << 20; /* min write limit is 32MB */ -uint64_t zfs_write_limit_max = 0; /* max data payload per txg */ -uint64_t zfs_write_limit_inflated = 0; -uint64_t zfs_write_limit_override = 0; +/* + * 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; -kmutex_t zfs_write_limit_lock; +/* + * 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; -static pgcnt_t old_physmem = 0; +hrtime_t zfs_throttle_delay = MSEC2NSEC(10); +hrtime_t zfs_throttle_resolution = MSEC2NSEC(10); int dsl_pool_open_special_dir(dsl_pool_t *dp, const char *name, dsl_dir_t **ddp) @@ -65,7 +141,7 @@ dsl_pool_open_special_dir(dsl_pool_t *dp, const char *name, dsl_dir_t **ddp) if (err) return (err); - return (dsl_dir_open_obj(dp, obj, name, dp, ddp)); + return (dsl_dir_hold_obj(dp, obj, name, dp, ddp)); } static dsl_pool_t * @@ -77,49 +153,59 @@ dsl_pool_open_impl(spa_t *spa, uint64_t txg) dp = kmem_zalloc(sizeof (dsl_pool_t), KM_SLEEP); dp->dp_spa = spa; dp->dp_meta_rootbp = *bp; - rw_init(&dp->dp_config_rwlock, NULL, RW_DEFAULT, NULL); - dp->dp_write_limit = zfs_write_limit_min; + rrw_init(&dp->dp_config_rwlock, B_TRUE); txg_init(dp, txg); txg_list_create(&dp->dp_dirty_datasets, offsetof(dsl_dataset_t, ds_dirty_link)); + txg_list_create(&dp->dp_dirty_zilogs, + offsetof(zilog_t, zl_dirty_link)); txg_list_create(&dp->dp_dirty_dirs, offsetof(dsl_dir_t, dd_dirty_link)); txg_list_create(&dp->dp_sync_tasks, - offsetof(dsl_sync_task_group_t, dstg_node)); - list_create(&dp->dp_synced_datasets, sizeof (dsl_dataset_t), - offsetof(dsl_dataset_t, ds_synced_link)); + offsetof(dsl_sync_task_t, dst_node)); mutex_init(&dp->dp_lock, NULL, MUTEX_DEFAULT, NULL); + cv_init(&dp->dp_spaceavail_cv, NULL, CV_DEFAULT, NULL); - dp->dp_vnrele_taskq = taskq_create("zfs_vn_rele_taskq", 1, minclsyspri, + dp->dp_iput_taskq = taskq_create("zfs_iput_taskq", 1, minclsyspri, 1, 4, 0); return (dp); } int -dsl_pool_open(spa_t *spa, uint64_t txg, dsl_pool_t **dpp) +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); - dsl_dir_t *dd; - dsl_dataset_t *ds; - uint64_t obj; - rw_enter(&dp->dp_config_rwlock, RW_WRITER); err = dmu_objset_open_impl(spa, NULL, &dp->dp_meta_rootbp, &dp->dp_meta_objset); - if (err) - goto out; + if (err != 0) + dsl_pool_close(dp); + else + *dpp = dp; + + 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_open_obj(dp, dp->dp_root_dir_obj, + err = dsl_dir_hold_obj(dp, dp->dp_root_dir_obj, NULL, dp, &dp->dp_root_dir); if (err) goto out; @@ -128,7 +214,7 @@ dsl_pool_open(spa_t *spa, uint64_t txg, dsl_pool_t **dpp) if (err) goto out; - if (spa_version(spa) >= SPA_VERSION_ORIGIN) { + if (spa_version(dp->dp_spa) >= SPA_VERSION_ORIGIN) { err = dsl_pool_open_special_dir(dp, ORIGIN_DIR_NAME, &dd); if (err) goto out; @@ -140,12 +226,12 @@ dsl_pool_open(spa_t *spa, uint64_t txg, dsl_pool_t **dpp) &dp->dp_origin_snap); dsl_dataset_rele(ds, FTAG); } - dsl_dir_close(dd, dp); + dsl_dir_rele(dd, dp); if (err) goto out; } - if (spa_version(spa) >= SPA_VERSION_DEADLISTS) { + 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) @@ -155,10 +241,28 @@ dsl_pool_open(spa_t *spa, uint64_t txg, dsl_pool_t **dpp) DMU_POOL_FREE_BPOBJ, sizeof (uint64_t), 1, &obj); if (err) goto out; - VERIFY3U(0, ==, bpobj_open(&dp->dp_free_bpobj, + VERIFY0(bpobj_open(&dp->dp_free_bpobj, dp->dp_meta_objset, obj)); } + if (spa_feature_is_active(dp->dp_spa, + &spa_feature_table[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_table[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); @@ -167,36 +271,31 @@ dsl_pool_open(spa_t *spa, uint64_t txg, dsl_pool_t **dpp) if (err) goto out; - err = dsl_scan_init(dp, txg); + err = dsl_scan_init(dp, dp->dp_tx.tx_open_txg); out: - rw_exit(&dp->dp_config_rwlock); - if (err) - dsl_pool_close(dp); - else - *dpp = dp; - + rrw_exit(&dp->dp_config_rwlock, FTAG); return (err); } void dsl_pool_close(dsl_pool_t *dp) { - /* drop our references from dsl_pool_open() */ - /* + * 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_drop_ref(dp->dp_origin_snap, dp); + dsl_dataset_rele(dp->dp_origin_snap, dp); if (dp->dp_mos_dir) - dsl_dir_close(dp->dp_mos_dir, dp); + dsl_dir_rele(dp->dp_mos_dir, dp); if (dp->dp_free_dir) - dsl_dir_close(dp->dp_free_dir, dp); + dsl_dir_rele(dp->dp_free_dir, dp); if (dp->dp_root_dir) - dsl_dir_close(dp->dp_root_dir, dp); + dsl_dir_rele(dp->dp_root_dir, dp); bpobj_close(&dp->dp_free_bpobj); @@ -205,16 +304,16 @@ dsl_pool_close(dsl_pool_t *dp) 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); - list_destroy(&dp->dp_synced_datasets); arc_flush(dp->dp_spa); txg_fini(dp); dsl_scan_fini(dp); - rw_destroy(&dp->dp_config_rwlock); + rrw_destroy(&dp->dp_config_rwlock); mutex_destroy(&dp->dp_lock); - taskq_destroy(dp->dp_vnrele_taskq); + taskq_destroy(dp->dp_iput_taskq); if (dp->dp_blkstats) kmem_free(dp->dp_blkstats, sizeof (zfs_all_blkstats_t)); kmem_free(dp, sizeof (dsl_pool_t)); @@ -230,6 +329,8 @@ dsl_pool_create(spa_t *spa, nvlist_t *zplprops, uint64_t txg) 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); @@ -237,33 +338,33 @@ dsl_pool_create(spa_t *spa, nvlist_t *zplprops, uint64_t txg) /* 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); - ASSERT3U(err, ==, 0); + ASSERT0(err); /* Initialize scan structures */ - VERIFY3U(0, ==, dsl_scan_init(dp, txg)); + 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); - VERIFY(0 == dsl_dir_open_obj(dp, dp->dp_root_dir_obj, + 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); - VERIFY(0 == dsl_pool_open_special_dir(dp, + 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); - VERIFY(0 == dsl_pool_open_special_dir(dp, + 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_MAXBLOCKSIZE, tx); VERIFY(zap_add(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_FREE_BPOBJ, sizeof (uint64_t), 1, &obj, tx) == 0); - VERIFY3U(0, ==, bpobj_open(&dp->dp_free_bpobj, + VERIFY0(bpobj_open(&dp->dp_free_bpobj, dp->dp_meta_objset, obj)); } @@ -274,9 +375,9 @@ dsl_pool_create(spa_t *spa, nvlist_t *zplprops, uint64_t txg) obj = dsl_dataset_create_sync_dd(dp->dp_root_dir, NULL, 0, tx); /* create the root objset */ - VERIFY(0 == dsl_dataset_hold_obj(dp, obj, FTAG, &ds)); - os = dmu_objset_create_impl(dp->dp_spa, ds, - dsl_dataset_get_blkptr(ds), DMU_OST_ZFS, tx); + VERIFY0(dsl_dataset_hold_obj(dp, obj, FTAG, &ds)); + VERIFY(NULL != (os = dmu_objset_create_impl(dp->dp_spa, ds, + dsl_dataset_get_blkptr(ds), DMU_OST_ZFS, tx))); #ifdef _KERNEL zfs_create_fs(os, kcred, zplprops, tx); #endif @@ -284,9 +385,26 @@ dsl_pool_create(spa_t *spa, nvlist_t *zplprops, uint64_t txg) 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 int deadlist_enqueue_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx) { @@ -295,6 +413,34 @@ deadlist_enqueue_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx) return (0); } +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) { @@ -302,158 +448,138 @@ dsl_pool_sync(dsl_pool_t *dp, uint64_t txg) dmu_tx_t *tx; dsl_dir_t *dd; dsl_dataset_t *ds; - dsl_sync_task_group_t *dstg; objset_t *mos = dp->dp_meta_objset; - hrtime_t start, write_time; - uint64_t data_written; - int err; + list_t synced_datasets; - /* - * We need to copy dp_space_towrite() before doing - * dsl_sync_task_group_sync(), because - * dsl_dataset_snapshot_reserve_space() will increase - * dp_space_towrite but not actually write anything. - */ - data_written = dp->dp_space_towrite[txg & TXG_MASK]; + list_create(&synced_datasets, sizeof (dsl_dataset_t), + offsetof(dsl_dataset_t, ds_synced_link)); tx = dmu_tx_create_assigned(dp, txg); - dp->dp_read_overhead = 0; - start = gethrtime(); - + /* + * 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)) { + 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(&dp->dp_synced_datasets, ds); + list_insert_tail(&synced_datasets, ds); dsl_dataset_sync(ds, zio, tx); } - DTRACE_PROBE(pool_sync__1setup); - err = zio_wait(zio); + VERIFY0(zio_wait(zio)); - write_time = gethrtime() - start; - ASSERT(err == 0); - DTRACE_PROBE(pool_sync__2rootzio); + /* + * 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); - for (ds = list_head(&dp->dp_synced_datasets); ds; - ds = list_next(&dp->dp_synced_datasets, ds)) + /* + * After the data blocks have been written (ensured by the zio_wait() + * above), update the user/group space accounting. + */ + for (ds = list_head(&synced_datasets); ds != NULL; + ds = list_next(&synced_datasets, ds)) { dmu_objset_do_userquota_updates(ds->ds_objset, tx); + } /* * Sync the datasets again to push out the changes due to * userspace updates. This must be done before we process the - * sync tasks, because that could cause a snapshot of a dataset - * whose ds_bp will be rewritten when we do this 2nd sync. + * 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)) { + 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); } - err = zio_wait(zio); + VERIFY0(zio_wait(zio)); /* - * Move dead blocks from the pending deadlist to the on-disk - * deadlist. + * 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() */ - for (ds = list_head(&dp->dp_synced_datasets); ds; - ds = list_next(&dp->dp_synced_datasets, ds)) { + while ((ds = list_remove_head(&synced_datasets)) != NULL) { + ASSERTV(objset_t *os = ds->ds_objset); bplist_iterate(&ds->ds_pending_deadlist, deadlist_enqueue_cb, &ds->ds_deadlist, tx); + ASSERT(!dmu_objset_is_dirty(os, txg)); + dmu_buf_rele(ds->ds_dbuf, ds); } - while (dstg = txg_list_remove(&dp->dp_sync_tasks, txg)) { - /* - * No more sync tasks should have been added while we - * were syncing. - */ - ASSERT(spa_sync_pass(dp->dp_spa) == 1); - dsl_sync_task_group_sync(dstg, tx); + while ((dd = txg_list_remove(&dp->dp_dirty_dirs, txg)) != NULL) { + dsl_dir_sync(dd, tx); } - DTRACE_PROBE(pool_sync__3task); - start = gethrtime(); - while (dd = txg_list_remove(&dp->dp_dirty_dirs, txg)) - dsl_dir_sync(dd, tx); - write_time += gethrtime() - start; + /* + * 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; + } - start = gethrtime(); if (list_head(&mos->os_dirty_dnodes[txg & TXG_MASK]) != NULL || list_head(&mos->os_free_dnodes[txg & TXG_MASK]) != NULL) { - zio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED); - dmu_objset_sync(mos, zio, tx); - err = zio_wait(zio); - ASSERT(err == 0); - dprintf_bp(&dp->dp_meta_rootbp, "meta objset rootbp is %s", ""); - spa_set_rootblkptr(dp->dp_spa, &dp->dp_meta_rootbp); + dsl_pool_sync_mos(dp, tx); } - write_time += gethrtime() - start; - DTRACE_PROBE2(pool_sync__4io, hrtime_t, write_time, - hrtime_t, dp->dp_read_overhead); - write_time -= dp->dp_read_overhead; - - dmu_tx_commit(tx); - - dp->dp_space_towrite[txg & TXG_MASK] = 0; - ASSERT(dp->dp_tempreserved[txg & TXG_MASK] == 0); /* - * If the write limit max has not been explicitly set, set it - * to a fraction of available physical memory (default 1/8th). - * Note that we must inflate the limit because the spa - * inflates write sizes to account for data replication. - * Check this each sync phase to catch changing memory size. + * 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 (physmem != old_physmem && zfs_write_limit_shift) { - mutex_enter(&zfs_write_limit_lock); - old_physmem = physmem; - zfs_write_limit_max = ptob(physmem) >> zfs_write_limit_shift; - zfs_write_limit_inflated = MAX(zfs_write_limit_min, - spa_get_asize(dp->dp_spa, zfs_write_limit_max)); - mutex_exit(&zfs_write_limit_lock); + 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); } - /* - * Attempt to keep the sync time consistent by adjusting the - * amount of write traffic allowed into each transaction group. - * Weight the throughput calculation towards the current value: - * thru = 3/4 old_thru + 1/4 new_thru - * - * Note: write_time is in nanosecs, so write_time/MICROSEC - * yields millisecs - */ - ASSERT(zfs_write_limit_min > 0); - if (data_written > zfs_write_limit_min / 8 && write_time > MICROSEC) { - uint64_t throughput = data_written / (write_time / MICROSEC); - - if (dp->dp_throughput) - dp->dp_throughput = throughput / 4 + - 3 * dp->dp_throughput / 4; - else - dp->dp_throughput = throughput; - dp->dp_write_limit = MIN(zfs_write_limit_inflated, - MAX(zfs_write_limit_min, - dp->dp_throughput * zfs_txg_synctime_ms)); - } + 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) { - dsl_dataset_t *ds; - objset_t *os; + zilog_t *zilog; - while (ds = list_head(&dp->dp_synced_datasets)) { - list_remove(&dp->dp_synced_datasets, ds); - os = ds->ds_objset; - zil_clean(os->os_zil); - ASSERT(!dmu_objset_is_dirty(os, txg)); - dmu_buf_rele(ds->ds_dbuf, ds); + while ((zilog = txg_list_remove(&dp->dp_dirty_zilogs, txg))) { + dsl_dataset_t *ds = dmu_objset_ds(zilog->zl_os); + zil_clean(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)); } @@ -466,7 +592,7 @@ int dsl_pool_sync_context(dsl_pool_t *dp) { return (curthread == dp->dp_tx.tx_sync_thread || - spa_get_dsl(dp->dp_spa) == NULL); + spa_is_initializing(dp->dp_spa)); } uint64_t @@ -492,92 +618,60 @@ dsl_pool_adjustedsize(dsl_pool_t *dp, boolean_t netfree) return (space - resv); } -int -dsl_pool_tempreserve_space(dsl_pool_t *dp, uint64_t space, dmu_tx_t *tx) +boolean_t +dsl_pool_need_dirty_delay(dsl_pool_t *dp) { - uint64_t reserved = 0; - uint64_t write_limit = (zfs_write_limit_override ? - zfs_write_limit_override : dp->dp_write_limit); - - if (zfs_no_write_throttle) { - atomic_add_64(&dp->dp_tempreserved[tx->tx_txg & TXG_MASK], - space); - return (0); - } - - /* - * Check to see if we have exceeded the maximum allowed IO for - * this transaction group. We can do this without locks since - * a little slop here is ok. Note that we do the reserved check - * with only half the requested reserve: this is because the - * reserve requests are worst-case, and we really don't want to - * throttle based off of worst-case estimates. - */ - if (write_limit > 0) { - reserved = dp->dp_space_towrite[tx->tx_txg & TXG_MASK] - + dp->dp_tempreserved[tx->tx_txg & TXG_MASK] / 2; - - if (reserved && reserved > write_limit) - return (ERESTART); - } - - atomic_add_64(&dp->dp_tempreserved[tx->tx_txg & TXG_MASK], space); - - /* - * If this transaction group is over 7/8ths capacity, delay - * the caller 1 clock tick. This will slow down the "fill" - * rate until the sync process can catch up with us. - */ - if (reserved && reserved > (write_limit - (write_limit >> 3))) - txg_delay(dp, tx->tx_txg, 1); - - return (0); + 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_tempreserve_clear(dsl_pool_t *dp, int64_t space, dmu_tx_t *tx) +dsl_pool_dirty_space(dsl_pool_t *dp, int64_t space, dmu_tx_t *tx) { - ASSERT(dp->dp_tempreserved[tx->tx_txg & TXG_MASK] >= space); - atomic_add_64(&dp->dp_tempreserved[tx->tx_txg & TXG_MASK], -space); + 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_memory_pressure(dsl_pool_t *dp) +dsl_pool_undirty_space(dsl_pool_t *dp, int64_t space, uint64_t txg) { - uint64_t space_inuse = 0; - int i; - - if (dp->dp_write_limit == zfs_write_limit_min) + ASSERT3S(space, >=, 0); + if (space == 0) return; - for (i = 0; i < TXG_SIZE; i++) { - space_inuse += dp->dp_space_towrite[i]; - space_inuse += dp->dp_tempreserved[i]; - } - dp->dp_write_limit = MAX(zfs_write_limit_min, - MIN(dp->dp_write_limit, space_inuse / 4)); -} - -void -dsl_pool_willuse_space(dsl_pool_t *dp, int64_t space, dmu_tx_t *tx) -{ - if (space > 0) { - mutex_enter(&dp->dp_lock); - dp->dp_space_towrite[tx->tx_txg & TXG_MASK] += space; - mutex_exit(&dp->dp_lock); + 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(spa_t *spa, uint64_t dsobj, const char *dsname, void *arg) +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; - dsl_pool_t *dp = spa_get_dsl(spa); - err = dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds); + err = dsl_dataset_hold_obj(dp, hds->ds_object, FTAG, &ds); if (err) return (err); @@ -603,7 +697,7 @@ upgrade_clones_cb(spa_t *spa, uint64_t dsobj, const char *dsname, void *arg) * The $ORIGIN can't have any data, or the accounting * will be wrong. */ - ASSERT(prev->ds_phys->ds_bp.blk_birth == 0); + ASSERT0(prev->ds_phys->ds_bp.blk_birth); /* The origin doesn't get attached to itself */ if (ds->ds_object == prev->ds_object) { @@ -623,13 +717,13 @@ upgrade_clones_cb(spa_t *spa, uint64_t dsobj, const char *dsname, void *arg) if (ds->ds_phys->ds_next_snap_obj == 0) { ASSERT(ds->ds_prev == NULL); - VERIFY(0 == dsl_dataset_hold_obj(dp, + VERIFY0(dsl_dataset_hold_obj(dp, ds->ds_phys->ds_prev_snap_obj, ds, &ds->ds_prev)); } } - ASSERT(ds->ds_dir->dd_phys->dd_origin_obj == prev->ds_object); - ASSERT(ds->ds_phys->ds_prev_snap_obj == prev->ds_object); + ASSERT3U(ds->ds_dir->dd_phys->dd_origin_obj, ==, prev->ds_object); + ASSERT3U(ds->ds_phys->ds_prev_snap_obj, ==, prev->ds_object); if (prev->ds_phys->ds_next_clones_obj == 0) { dmu_buf_will_dirty(prev->ds_dbuf, tx); @@ -637,7 +731,7 @@ upgrade_clones_cb(spa_t *spa, uint64_t dsobj, const char *dsname, void *arg) zap_create(dp->dp_meta_objset, DMU_OT_NEXT_CLONES, DMU_OT_NONE, 0, tx); } - VERIFY(0 == zap_add_int(dp->dp_meta_objset, + VERIFY0(zap_add_int(dp->dp_meta_objset, prev->ds_phys->ds_next_clones_obj, ds->ds_object, tx)); dsl_dataset_rele(ds, FTAG); @@ -652,25 +746,21 @@ dsl_pool_upgrade_clones(dsl_pool_t *dp, dmu_tx_t *tx) ASSERT(dmu_tx_is_syncing(tx)); ASSERT(dp->dp_origin_snap != NULL); - VERIFY3U(0, ==, dmu_objset_find_spa(dp->dp_spa, NULL, upgrade_clones_cb, + VERIFY0(dmu_objset_find_dp(dp, dp->dp_root_dir_obj, upgrade_clones_cb, tx, DS_FIND_CHILDREN)); } /* ARGSUSED */ static int -upgrade_dir_clones_cb(spa_t *spa, uint64_t dsobj, const char *dsname, void *arg) +upgrade_dir_clones_cb(dsl_pool_t *dp, dsl_dataset_t *ds, void *arg) { dmu_tx_t *tx = arg; - dsl_dataset_t *ds; - dsl_pool_t *dp = spa_get_dsl(spa); objset_t *mos = dp->dp_meta_objset; - VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds)); - - if (ds->ds_dir->dd_phys->dd_origin_obj) { + if (ds->ds_dir->dd_phys->dd_origin_obj != 0) { dsl_dataset_t *origin; - VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, + VERIFY0(dsl_dataset_hold_obj(dp, ds->ds_dir->dd_phys->dd_origin_obj, FTAG, &origin)); if (origin->ds_dir->dd_phys->dd_clones == 0) { @@ -679,24 +769,23 @@ upgrade_dir_clones_cb(spa_t *spa, uint64_t dsobj, const char *dsname, void *arg) DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx); } - VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset, - origin->ds_dir->dd_phys->dd_clones, dsobj, tx)); + VERIFY0(zap_add_int(dp->dp_meta_objset, + origin->ds_dir->dd_phys->dd_clones, ds->ds_object, tx)); dsl_dataset_rele(origin, FTAG); } - - dsl_dataset_rele(ds, FTAG); return (0); } void dsl_pool_upgrade_dir_clones(dsl_pool_t *dp, dmu_tx_t *tx) { - ASSERT(dmu_tx_is_syncing(tx)); uint64_t obj; + ASSERT(dmu_tx_is_syncing(tx)); + (void) dsl_dir_create_sync(dp, dp->dp_root_dir, FREE_DIR_NAME, tx); - VERIFY(0 == dsl_pool_open_special_dir(dp, + VERIFY0(dsl_pool_open_special_dir(dp, FREE_DIR_NAME, &dp->dp_free_dir)); /* @@ -706,12 +795,11 @@ dsl_pool_upgrade_dir_clones(dsl_pool_t *dp, dmu_tx_t *tx) */ obj = dmu_object_alloc(dp->dp_meta_objset, DMU_OT_BPOBJ, SPA_MAXBLOCKSIZE, DMU_OT_BPOBJ_HDR, sizeof (bpobj_phys_t), tx); - VERIFY3U(0, ==, zap_add(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, + VERIFY0(zap_add(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_FREE_BPOBJ, sizeof (uint64_t), 1, &obj, tx)); - VERIFY3U(0, ==, bpobj_open(&dp->dp_free_bpobj, - dp->dp_meta_objset, obj)); + VERIFY0(bpobj_open(&dp->dp_free_bpobj, dp->dp_meta_objset, obj)); - VERIFY3U(0, ==, dmu_objset_find_spa(dp->dp_spa, NULL, + VERIFY0(dmu_objset_find_dp(dp, dp->dp_root_dir_obj, upgrade_dir_clones_cb, tx, DS_FIND_CHILDREN)); } @@ -723,23 +811,22 @@ dsl_pool_create_origin(dsl_pool_t *dp, dmu_tx_t *tx) 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 */ - rw_enter(&dp->dp_config_rwlock, RW_WRITER); dsobj = dsl_dataset_create_sync(dp->dp_root_dir, ORIGIN_DIR_NAME, NULL, 0, kcred, tx); - VERIFY(0 == dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds)); - dsl_dataset_snapshot_sync(ds, ORIGIN_DIR_NAME, tx); - VERIFY(0 == dsl_dataset_hold_obj(dp, ds->ds_phys->ds_prev_snap_obj, + 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, ds->ds_phys->ds_prev_snap_obj, dp, &dp->dp_origin_snap)); dsl_dataset_rele(ds, FTAG); - rw_exit(&dp->dp_config_rwlock); } taskq_t * -dsl_pool_vnrele_taskq(dsl_pool_t *dp) +dsl_pool_iput_taskq(dsl_pool_t *dp) { - return (dp->dp_vnrele_taskq); + return (dp->dp_iput_taskq); } /* @@ -753,23 +840,34 @@ dsl_pool_clean_tmp_userrefs(dsl_pool_t *dp) 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; - uint64_t dsobj; + nvlist_t *tags; htag = strchr(za.za_name, '-'); *htag = '\0'; ++htag; - dsobj = strtonum(za.za_name, NULL); - (void) dsl_dataset_user_release_tmp(dp, dsobj, 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); } @@ -784,16 +882,13 @@ dsl_pool_user_hold_create_obj(dsl_pool_t *dp, dmu_tx_t *tx) ASSERT(dp->dp_tmp_userrefs_obj == 0); ASSERT(dmu_tx_is_syncing(tx)); - dp->dp_tmp_userrefs_obj = zap_create(mos, DMU_OT_USERREFS, - DMU_OT_NONE, 0, tx); - - VERIFY(zap_add(mos, DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_TMP_USERREFS, - sizeof (uint64_t), 1, &dp->dp_tmp_userrefs_obj, tx) == 0); + 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) + 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; @@ -812,13 +907,13 @@ dsl_pool_user_hold_rele_impl(dsl_pool_t *dp, uint64_t dsobj, dsl_pool_user_hold_create_obj(dp, tx); zapobj = dp->dp_tmp_userrefs_obj; } else { - return (ENOENT); + 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); + error = zap_add(mos, zapobj, name, 8, 1, &now, tx); else error = zap_remove(mos, zapobj, name, tx); strfree(name); @@ -831,7 +926,7 @@ dsl_pool_user_hold_rele_impl(dsl_pool_t *dp, uint64_t dsobj, */ int dsl_pool_user_hold(dsl_pool_t *dp, uint64_t dsobj, const char *tag, - uint64_t *now, dmu_tx_t *tx) + uint64_t now, dmu_tx_t *tx) { return (dsl_pool_user_hold_rele_impl(dp, dsobj, tag, now, tx, B_TRUE)); } @@ -843,6 +938,140 @@ 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, NULL, + 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_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)); +} + +#if defined(_KERNEL) && defined(HAVE_SPL) +EXPORT_SYMBOL(dsl_pool_config_enter); +EXPORT_SYMBOL(dsl_pool_config_exit); + +/* 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"); +#endif