4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright (c) 2011 by Delphix. All rights reserved.
26 #include <sys/dsl_pool.h>
27 #include <sys/dsl_dataset.h>
28 #include <sys/dsl_prop.h>
29 #include <sys/dsl_dir.h>
30 #include <sys/dsl_synctask.h>
31 #include <sys/dsl_scan.h>
32 #include <sys/dnode.h>
33 #include <sys/dmu_tx.h>
34 #include <sys/dmu_objset.h>
38 #include <sys/zfs_context.h>
39 #include <sys/fs/zfs.h>
40 #include <sys/zfs_znode.h>
41 #include <sys/spa_impl.h>
42 #include <sys/dsl_deadlist.h>
44 int zfs_no_write_throttle = 0;
45 int zfs_write_limit_shift = 3; /* 1/8th of physical memory */
46 int zfs_txg_synctime_ms = 1000; /* target millisecs to sync a txg */
47 int zfs_txg_history = 60; /* statistics for the last N txgs */
49 unsigned long zfs_write_limit_min = 32 << 20; /* min write limit is 32MB */
50 unsigned long zfs_write_limit_max = 0; /* max data payload per txg */
51 unsigned long zfs_write_limit_inflated = 0;
52 unsigned long zfs_write_limit_override = 0;
54 kmutex_t zfs_write_limit_lock;
56 static pgcnt_t old_physmem = 0;
59 dsl_pool_txg_history_update(kstat_t *ksp, int rw)
61 dsl_pool_t *dp = ksp->ks_private;
65 if (rw == KSTAT_WRITE)
69 kmem_free(ksp->ks_data, ksp->ks_data_size);
71 mutex_enter(&dp->dp_lock);
73 ksp->ks_ndata = dp->dp_txg_history_size;
74 ksp->ks_data_size = dp->dp_txg_history_size * sizeof(kstat_txg_t);
75 if (ksp->ks_data_size > 0)
76 ksp->ks_data = kmem_alloc(ksp->ks_data_size, KM_PUSHPAGE);
78 /* Traversed oldest to youngest for the most readable kstat output */
79 for (th = list_tail(&dp->dp_txg_history); th != NULL;
80 th = list_prev(&dp->dp_txg_history, th)) {
81 mutex_enter(&th->th_lock);
82 ASSERT3S(i + sizeof(kstat_txg_t), <=, ksp->ks_data_size);
83 memcpy(ksp->ks_data + i, &th->th_kstat, sizeof(kstat_txg_t));
84 i += sizeof(kstat_txg_t);
85 mutex_exit(&th->th_lock);
88 mutex_exit(&dp->dp_lock);
94 dsl_pool_txg_history_init(dsl_pool_t *dp, uint64_t txg)
96 char name[KSTAT_STRLEN];
98 list_create(&dp->dp_txg_history, sizeof (txg_history_t),
99 offsetof(txg_history_t, th_link));
100 dsl_pool_txg_history_add(dp, txg);
102 (void) snprintf(name, KSTAT_STRLEN, "txgs-%s", spa_name(dp->dp_spa));
103 dp->dp_txg_kstat = kstat_create("zfs", 0, name, "misc",
104 KSTAT_TYPE_TXG, 0, KSTAT_FLAG_VIRTUAL);
105 if (dp->dp_txg_kstat) {
106 dp->dp_txg_kstat->ks_data = NULL;
107 dp->dp_txg_kstat->ks_private = dp;
108 dp->dp_txg_kstat->ks_update = dsl_pool_txg_history_update;
109 kstat_install(dp->dp_txg_kstat);
114 dsl_pool_txg_history_destroy(dsl_pool_t *dp)
118 if (dp->dp_txg_kstat) {
119 if (dp->dp_txg_kstat->ks_data)
120 kmem_free(dp->dp_txg_kstat->ks_data,
121 dp->dp_txg_kstat->ks_data_size);
123 kstat_delete(dp->dp_txg_kstat);
126 mutex_enter(&dp->dp_lock);
127 while ((th = list_remove_head(&dp->dp_txg_history))) {
128 dp->dp_txg_history_size--;
129 mutex_destroy(&th->th_lock);
130 kmem_free(th, sizeof(txg_history_t));
133 ASSERT3U(dp->dp_txg_history_size, ==, 0);
134 list_destroy(&dp->dp_txg_history);
135 mutex_exit(&dp->dp_lock);
139 dsl_pool_txg_history_add(dsl_pool_t *dp, uint64_t txg)
141 txg_history_t *th, *rm;
143 th = kmem_zalloc(sizeof(txg_history_t), KM_SLEEP);
144 mutex_init(&th->th_lock, NULL, MUTEX_DEFAULT, NULL);
145 th->th_kstat.txg = txg;
146 th->th_kstat.state = TXG_STATE_OPEN;
147 th->th_kstat.birth = gethrtime();
149 mutex_enter(&dp->dp_lock);
151 list_insert_head(&dp->dp_txg_history, th);
152 dp->dp_txg_history_size++;
154 while (dp->dp_txg_history_size > zfs_txg_history) {
155 dp->dp_txg_history_size--;
156 rm = list_remove_tail(&dp->dp_txg_history);
157 mutex_destroy(&rm->th_lock);
158 kmem_free(rm, sizeof(txg_history_t));
161 mutex_exit(&dp->dp_lock);
167 * Traversed youngest to oldest because lookups are only done for open
168 * or syncing txgs which are guaranteed to be at the head of the list.
169 * The txg_history_t structure will be returned locked.
172 dsl_pool_txg_history_get(dsl_pool_t *dp, uint64_t txg)
176 mutex_enter(&dp->dp_lock);
177 for (th = list_head(&dp->dp_txg_history); th != NULL;
178 th = list_next(&dp->dp_txg_history, th)) {
179 if (th->th_kstat.txg == txg) {
180 mutex_enter(&th->th_lock);
184 mutex_exit(&dp->dp_lock);
190 dsl_pool_txg_history_put(txg_history_t *th)
192 mutex_exit(&th->th_lock);
196 dsl_pool_open_special_dir(dsl_pool_t *dp, const char *name, dsl_dir_t **ddp)
201 err = zap_lookup(dp->dp_meta_objset,
202 dp->dp_root_dir->dd_phys->dd_child_dir_zapobj,
203 name, sizeof (obj), 1, &obj);
207 return (dsl_dir_open_obj(dp, obj, name, dp, ddp));
211 dsl_pool_open_impl(spa_t *spa, uint64_t txg)
214 blkptr_t *bp = spa_get_rootblkptr(spa);
216 dp = kmem_zalloc(sizeof (dsl_pool_t), KM_SLEEP);
218 dp->dp_meta_rootbp = *bp;
219 rw_init(&dp->dp_config_rwlock, NULL, RW_DEFAULT, NULL);
220 dp->dp_write_limit = zfs_write_limit_min;
223 txg_list_create(&dp->dp_dirty_datasets,
224 offsetof(dsl_dataset_t, ds_dirty_link));
225 txg_list_create(&dp->dp_dirty_dirs,
226 offsetof(dsl_dir_t, dd_dirty_link));
227 txg_list_create(&dp->dp_sync_tasks,
228 offsetof(dsl_sync_task_group_t, dstg_node));
229 list_create(&dp->dp_synced_datasets, sizeof (dsl_dataset_t),
230 offsetof(dsl_dataset_t, ds_synced_link));
232 mutex_init(&dp->dp_lock, NULL, MUTEX_DEFAULT, NULL);
234 dp->dp_iput_taskq = taskq_create("zfs_iput_taskq", 1, minclsyspri,
237 dsl_pool_txg_history_init(dp, txg);
243 dsl_pool_open(spa_t *spa, uint64_t txg, dsl_pool_t **dpp)
246 dsl_pool_t *dp = dsl_pool_open_impl(spa, txg);
251 rw_enter(&dp->dp_config_rwlock, RW_WRITER);
252 err = dmu_objset_open_impl(spa, NULL, &dp->dp_meta_rootbp,
253 &dp->dp_meta_objset);
257 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
258 DMU_POOL_ROOT_DATASET, sizeof (uint64_t), 1,
259 &dp->dp_root_dir_obj);
263 err = dsl_dir_open_obj(dp, dp->dp_root_dir_obj,
264 NULL, dp, &dp->dp_root_dir);
268 err = dsl_pool_open_special_dir(dp, MOS_DIR_NAME, &dp->dp_mos_dir);
272 if (spa_version(spa) >= SPA_VERSION_ORIGIN) {
273 err = dsl_pool_open_special_dir(dp, ORIGIN_DIR_NAME, &dd);
276 err = dsl_dataset_hold_obj(dp, dd->dd_phys->dd_head_dataset_obj,
279 err = dsl_dataset_hold_obj(dp,
280 ds->ds_phys->ds_prev_snap_obj, dp,
281 &dp->dp_origin_snap);
282 dsl_dataset_rele(ds, FTAG);
284 dsl_dir_close(dd, dp);
289 if (spa_version(spa) >= SPA_VERSION_DEADLISTS) {
290 err = dsl_pool_open_special_dir(dp, FREE_DIR_NAME,
295 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
296 DMU_POOL_FREE_BPOBJ, sizeof (uint64_t), 1, &obj);
299 VERIFY3U(0, ==, bpobj_open(&dp->dp_free_bpobj,
300 dp->dp_meta_objset, obj));
303 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
304 DMU_POOL_TMP_USERREFS, sizeof (uint64_t), 1,
305 &dp->dp_tmp_userrefs_obj);
311 err = dsl_scan_init(dp, txg);
314 rw_exit(&dp->dp_config_rwlock);
324 dsl_pool_close(dsl_pool_t *dp)
326 /* drop our references from dsl_pool_open() */
329 * Since we held the origin_snap from "syncing" context (which
330 * includes pool-opening context), it actually only got a "ref"
331 * and not a hold, so just drop that here.
333 if (dp->dp_origin_snap)
334 dsl_dataset_drop_ref(dp->dp_origin_snap, dp);
336 dsl_dir_close(dp->dp_mos_dir, dp);
338 dsl_dir_close(dp->dp_free_dir, dp);
340 dsl_dir_close(dp->dp_root_dir, dp);
342 bpobj_close(&dp->dp_free_bpobj);
344 /* undo the dmu_objset_open_impl(mos) from dsl_pool_open() */
345 if (dp->dp_meta_objset)
346 dmu_objset_evict(dp->dp_meta_objset);
348 txg_list_destroy(&dp->dp_dirty_datasets);
349 txg_list_destroy(&dp->dp_sync_tasks);
350 txg_list_destroy(&dp->dp_dirty_dirs);
351 list_destroy(&dp->dp_synced_datasets);
353 arc_flush(dp->dp_spa);
356 dsl_pool_txg_history_destroy(dp);
357 rw_destroy(&dp->dp_config_rwlock);
358 mutex_destroy(&dp->dp_lock);
359 taskq_destroy(dp->dp_iput_taskq);
361 kmem_free(dp->dp_blkstats, sizeof (zfs_all_blkstats_t));
362 kmem_free(dp, sizeof (dsl_pool_t));
366 dsl_pool_create(spa_t *spa, nvlist_t *zplprops, uint64_t txg)
369 dsl_pool_t *dp = dsl_pool_open_impl(spa, txg);
370 dmu_tx_t *tx = dmu_tx_create_assigned(dp, txg);
375 /* create and open the MOS (meta-objset) */
376 dp->dp_meta_objset = dmu_objset_create_impl(spa,
377 NULL, &dp->dp_meta_rootbp, DMU_OST_META, tx);
379 /* create the pool directory */
380 err = zap_create_claim(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
381 DMU_OT_OBJECT_DIRECTORY, DMU_OT_NONE, 0, tx);
382 ASSERT3U(err, ==, 0);
384 /* Initialize scan structures */
385 VERIFY3U(0, ==, dsl_scan_init(dp, txg));
387 /* create and open the root dir */
388 dp->dp_root_dir_obj = dsl_dir_create_sync(dp, NULL, NULL, tx);
389 VERIFY(0 == dsl_dir_open_obj(dp, dp->dp_root_dir_obj,
390 NULL, dp, &dp->dp_root_dir));
392 /* create and open the meta-objset dir */
393 (void) dsl_dir_create_sync(dp, dp->dp_root_dir, MOS_DIR_NAME, tx);
394 VERIFY(0 == dsl_pool_open_special_dir(dp,
395 MOS_DIR_NAME, &dp->dp_mos_dir));
397 if (spa_version(spa) >= SPA_VERSION_DEADLISTS) {
398 /* create and open the free dir */
399 (void) dsl_dir_create_sync(dp, dp->dp_root_dir,
401 VERIFY(0 == dsl_pool_open_special_dir(dp,
402 FREE_DIR_NAME, &dp->dp_free_dir));
404 /* create and open the free_bplist */
405 obj = bpobj_alloc(dp->dp_meta_objset, SPA_MAXBLOCKSIZE, tx);
406 VERIFY(zap_add(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
407 DMU_POOL_FREE_BPOBJ, sizeof (uint64_t), 1, &obj, tx) == 0);
408 VERIFY3U(0, ==, bpobj_open(&dp->dp_free_bpobj,
409 dp->dp_meta_objset, obj));
412 if (spa_version(spa) >= SPA_VERSION_DSL_SCRUB)
413 dsl_pool_create_origin(dp, tx);
415 /* create the root dataset */
416 obj = dsl_dataset_create_sync_dd(dp->dp_root_dir, NULL, 0, tx);
418 /* create the root objset */
419 VERIFY(0 == dsl_dataset_hold_obj(dp, obj, FTAG, &ds));
420 VERIFY(NULL != (os = dmu_objset_create_impl(dp->dp_spa, ds,
421 dsl_dataset_get_blkptr(ds), DMU_OST_ZFS, tx)));
423 zfs_create_fs(os, kcred, zplprops, tx);
425 dsl_dataset_rele(ds, FTAG);
433 deadlist_enqueue_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
435 dsl_deadlist_t *dl = arg;
436 dsl_pool_t *dp = dmu_objset_pool(dl->dl_os);
437 rw_enter(&dp->dp_config_rwlock, RW_READER);
438 dsl_deadlist_insert(dl, bp, tx);
439 rw_exit(&dp->dp_config_rwlock);
444 dsl_pool_sync(dsl_pool_t *dp, uint64_t txg)
450 dsl_sync_task_group_t *dstg;
451 objset_t *mos = dp->dp_meta_objset;
452 hrtime_t start, write_time;
453 uint64_t data_written;
457 * We need to copy dp_space_towrite() before doing
458 * dsl_sync_task_group_sync(), because
459 * dsl_dataset_snapshot_reserve_space() will increase
460 * dp_space_towrite but not actually write anything.
462 data_written = dp->dp_space_towrite[txg & TXG_MASK];
464 tx = dmu_tx_create_assigned(dp, txg);
466 dp->dp_read_overhead = 0;
469 zio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
470 while ((ds = txg_list_remove(&dp->dp_dirty_datasets, txg))) {
472 * We must not sync any non-MOS datasets twice, because
473 * we may have taken a snapshot of them. However, we
474 * may sync newly-created datasets on pass 2.
476 ASSERT(!list_link_active(&ds->ds_synced_link));
477 list_insert_tail(&dp->dp_synced_datasets, ds);
478 dsl_dataset_sync(ds, zio, tx);
480 DTRACE_PROBE(pool_sync__1setup);
483 write_time = gethrtime() - start;
485 DTRACE_PROBE(pool_sync__2rootzio);
487 for (ds = list_head(&dp->dp_synced_datasets); ds;
488 ds = list_next(&dp->dp_synced_datasets, ds))
489 dmu_objset_do_userquota_updates(ds->ds_objset, tx);
492 * Sync the datasets again to push out the changes due to
493 * userspace updates. This must be done before we process the
494 * sync tasks, because that could cause a snapshot of a dataset
495 * whose ds_bp will be rewritten when we do this 2nd sync.
497 zio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
498 while ((ds = txg_list_remove(&dp->dp_dirty_datasets, txg))) {
499 ASSERT(list_link_active(&ds->ds_synced_link));
500 dmu_buf_rele(ds->ds_dbuf, ds);
501 dsl_dataset_sync(ds, zio, tx);
506 * Move dead blocks from the pending deadlist to the on-disk
509 for (ds = list_head(&dp->dp_synced_datasets); ds;
510 ds = list_next(&dp->dp_synced_datasets, ds)) {
511 bplist_iterate(&ds->ds_pending_deadlist,
512 deadlist_enqueue_cb, &ds->ds_deadlist, tx);
515 while ((dstg = txg_list_remove(&dp->dp_sync_tasks, txg))) {
517 * No more sync tasks should have been added while we
520 ASSERT(spa_sync_pass(dp->dp_spa) == 1);
521 dsl_sync_task_group_sync(dstg, tx);
523 DTRACE_PROBE(pool_sync__3task);
526 while ((dd = txg_list_remove(&dp->dp_dirty_dirs, txg)))
527 dsl_dir_sync(dd, tx);
528 write_time += gethrtime() - start;
531 if (list_head(&mos->os_dirty_dnodes[txg & TXG_MASK]) != NULL ||
532 list_head(&mos->os_free_dnodes[txg & TXG_MASK]) != NULL) {
533 zio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
534 dmu_objset_sync(mos, zio, tx);
537 dprintf_bp(&dp->dp_meta_rootbp, "meta objset rootbp is %s", "");
538 spa_set_rootblkptr(dp->dp_spa, &dp->dp_meta_rootbp);
540 write_time += gethrtime() - start;
541 DTRACE_PROBE2(pool_sync__4io, hrtime_t, write_time,
542 hrtime_t, dp->dp_read_overhead);
543 write_time -= dp->dp_read_overhead;
547 dp->dp_space_towrite[txg & TXG_MASK] = 0;
548 ASSERT(dp->dp_tempreserved[txg & TXG_MASK] == 0);
551 * If the write limit max has not been explicitly set, set it
552 * to a fraction of available physical memory (default 1/8th).
553 * Note that we must inflate the limit because the spa
554 * inflates write sizes to account for data replication.
555 * Check this each sync phase to catch changing memory size.
557 if (physmem != old_physmem && zfs_write_limit_shift) {
558 mutex_enter(&zfs_write_limit_lock);
559 old_physmem = physmem;
560 zfs_write_limit_max = ptob(physmem) >> zfs_write_limit_shift;
561 zfs_write_limit_inflated = MAX(zfs_write_limit_min,
562 spa_get_asize(dp->dp_spa, zfs_write_limit_max));
563 mutex_exit(&zfs_write_limit_lock);
567 * Attempt to keep the sync time consistent by adjusting the
568 * amount of write traffic allowed into each transaction group.
569 * Weight the throughput calculation towards the current value:
570 * thru = 3/4 old_thru + 1/4 new_thru
572 * Note: write_time is in nanosecs, so write_time/MICROSEC
575 ASSERT(zfs_write_limit_min > 0);
576 if (data_written > zfs_write_limit_min / 8 && write_time > MICROSEC) {
577 uint64_t throughput = data_written / (write_time / MICROSEC);
579 if (dp->dp_throughput)
580 dp->dp_throughput = throughput / 4 +
581 3 * dp->dp_throughput / 4;
583 dp->dp_throughput = throughput;
584 dp->dp_write_limit = MIN(zfs_write_limit_inflated,
585 MAX(zfs_write_limit_min,
586 dp->dp_throughput * zfs_txg_synctime_ms));
591 dsl_pool_sync_done(dsl_pool_t *dp, uint64_t txg)
596 while ((ds = list_head(&dp->dp_synced_datasets))) {
597 list_remove(&dp->dp_synced_datasets, ds);
599 zil_clean(os->os_zil, txg);
600 ASSERT(!dmu_objset_is_dirty(os, txg));
601 dmu_buf_rele(ds->ds_dbuf, ds);
603 ASSERT(!dmu_objset_is_dirty(dp->dp_meta_objset, txg));
607 * TRUE if the current thread is the tx_sync_thread or if we
608 * are being called from SPA context during pool initialization.
611 dsl_pool_sync_context(dsl_pool_t *dp)
613 return (curthread == dp->dp_tx.tx_sync_thread ||
614 spa_get_dsl(dp->dp_spa) == NULL);
618 dsl_pool_adjustedsize(dsl_pool_t *dp, boolean_t netfree)
620 uint64_t space, resv;
623 * Reserve about 1.6% (1/64), or at least 32MB, for allocation
625 * XXX The intent log is not accounted for, so it must fit
628 * If we're trying to assess whether it's OK to do a free,
629 * cut the reservation in half to allow forward progress
630 * (e.g. make it possible to rm(1) files from a full pool).
632 space = spa_get_dspace(dp->dp_spa);
633 resv = MAX(space >> 6, SPA_MINDEVSIZE >> 1);
637 return (space - resv);
641 dsl_pool_tempreserve_space(dsl_pool_t *dp, uint64_t space, dmu_tx_t *tx)
643 uint64_t reserved = 0;
644 uint64_t write_limit = (zfs_write_limit_override ?
645 zfs_write_limit_override : dp->dp_write_limit);
647 if (zfs_no_write_throttle) {
648 atomic_add_64(&dp->dp_tempreserved[tx->tx_txg & TXG_MASK],
654 * Check to see if we have exceeded the maximum allowed IO for
655 * this transaction group. We can do this without locks since
656 * a little slop here is ok. Note that we do the reserved check
657 * with only half the requested reserve: this is because the
658 * reserve requests are worst-case, and we really don't want to
659 * throttle based off of worst-case estimates.
661 if (write_limit > 0) {
662 reserved = dp->dp_space_towrite[tx->tx_txg & TXG_MASK]
663 + dp->dp_tempreserved[tx->tx_txg & TXG_MASK] / 2;
665 if (reserved && reserved > write_limit) {
666 DMU_TX_STAT_BUMP(dmu_tx_write_limit);
671 atomic_add_64(&dp->dp_tempreserved[tx->tx_txg & TXG_MASK], space);
674 * If this transaction group is over 7/8ths capacity, delay
675 * the caller 1 clock tick. This will slow down the "fill"
676 * rate until the sync process can catch up with us.
678 if (reserved && reserved > (write_limit - (write_limit >> 3)))
679 txg_delay(dp, tx->tx_txg, 1);
685 dsl_pool_tempreserve_clear(dsl_pool_t *dp, int64_t space, dmu_tx_t *tx)
687 ASSERT(dp->dp_tempreserved[tx->tx_txg & TXG_MASK] >= space);
688 atomic_add_64(&dp->dp_tempreserved[tx->tx_txg & TXG_MASK], -space);
692 dsl_pool_memory_pressure(dsl_pool_t *dp)
694 uint64_t space_inuse = 0;
697 if (dp->dp_write_limit == zfs_write_limit_min)
700 for (i = 0; i < TXG_SIZE; i++) {
701 space_inuse += dp->dp_space_towrite[i];
702 space_inuse += dp->dp_tempreserved[i];
704 dp->dp_write_limit = MAX(zfs_write_limit_min,
705 MIN(dp->dp_write_limit, space_inuse / 4));
709 dsl_pool_willuse_space(dsl_pool_t *dp, int64_t space, dmu_tx_t *tx)
712 mutex_enter(&dp->dp_lock);
713 dp->dp_space_towrite[tx->tx_txg & TXG_MASK] += space;
714 mutex_exit(&dp->dp_lock);
720 upgrade_clones_cb(spa_t *spa, uint64_t dsobj, const char *dsname, void *arg)
723 dsl_dataset_t *ds, *prev = NULL;
725 dsl_pool_t *dp = spa_get_dsl(spa);
727 err = dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds);
731 while (ds->ds_phys->ds_prev_snap_obj != 0) {
732 err = dsl_dataset_hold_obj(dp, ds->ds_phys->ds_prev_snap_obj,
735 dsl_dataset_rele(ds, FTAG);
739 if (prev->ds_phys->ds_next_snap_obj != ds->ds_object)
741 dsl_dataset_rele(ds, FTAG);
747 prev = dp->dp_origin_snap;
750 * The $ORIGIN can't have any data, or the accounting
753 ASSERT(prev->ds_phys->ds_bp.blk_birth == 0);
755 /* The origin doesn't get attached to itself */
756 if (ds->ds_object == prev->ds_object) {
757 dsl_dataset_rele(ds, FTAG);
761 dmu_buf_will_dirty(ds->ds_dbuf, tx);
762 ds->ds_phys->ds_prev_snap_obj = prev->ds_object;
763 ds->ds_phys->ds_prev_snap_txg = prev->ds_phys->ds_creation_txg;
765 dmu_buf_will_dirty(ds->ds_dir->dd_dbuf, tx);
766 ds->ds_dir->dd_phys->dd_origin_obj = prev->ds_object;
768 dmu_buf_will_dirty(prev->ds_dbuf, tx);
769 prev->ds_phys->ds_num_children++;
771 if (ds->ds_phys->ds_next_snap_obj == 0) {
772 ASSERT(ds->ds_prev == NULL);
773 VERIFY(0 == dsl_dataset_hold_obj(dp,
774 ds->ds_phys->ds_prev_snap_obj, ds, &ds->ds_prev));
778 ASSERT(ds->ds_dir->dd_phys->dd_origin_obj == prev->ds_object);
779 ASSERT(ds->ds_phys->ds_prev_snap_obj == prev->ds_object);
781 if (prev->ds_phys->ds_next_clones_obj == 0) {
782 dmu_buf_will_dirty(prev->ds_dbuf, tx);
783 prev->ds_phys->ds_next_clones_obj =
784 zap_create(dp->dp_meta_objset,
785 DMU_OT_NEXT_CLONES, DMU_OT_NONE, 0, tx);
787 VERIFY(0 == zap_add_int(dp->dp_meta_objset,
788 prev->ds_phys->ds_next_clones_obj, ds->ds_object, tx));
790 dsl_dataset_rele(ds, FTAG);
791 if (prev != dp->dp_origin_snap)
792 dsl_dataset_rele(prev, FTAG);
797 dsl_pool_upgrade_clones(dsl_pool_t *dp, dmu_tx_t *tx)
799 ASSERT(dmu_tx_is_syncing(tx));
800 ASSERT(dp->dp_origin_snap != NULL);
802 VERIFY3U(0, ==, dmu_objset_find_spa(dp->dp_spa, NULL, upgrade_clones_cb,
803 tx, DS_FIND_CHILDREN));
808 upgrade_dir_clones_cb(spa_t *spa, uint64_t dsobj, const char *dsname, void *arg)
812 dsl_pool_t *dp = spa_get_dsl(spa);
813 objset_t *mos = dp->dp_meta_objset;
815 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds));
817 if (ds->ds_dir->dd_phys->dd_origin_obj) {
818 dsl_dataset_t *origin;
820 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp,
821 ds->ds_dir->dd_phys->dd_origin_obj, FTAG, &origin));
823 if (origin->ds_dir->dd_phys->dd_clones == 0) {
824 dmu_buf_will_dirty(origin->ds_dir->dd_dbuf, tx);
825 origin->ds_dir->dd_phys->dd_clones = zap_create(mos,
826 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx);
829 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset,
830 origin->ds_dir->dd_phys->dd_clones, dsobj, tx));
832 dsl_dataset_rele(origin, FTAG);
835 dsl_dataset_rele(ds, FTAG);
840 dsl_pool_upgrade_dir_clones(dsl_pool_t *dp, dmu_tx_t *tx)
844 ASSERT(dmu_tx_is_syncing(tx));
846 (void) dsl_dir_create_sync(dp, dp->dp_root_dir, FREE_DIR_NAME, tx);
847 VERIFY(0 == dsl_pool_open_special_dir(dp,
848 FREE_DIR_NAME, &dp->dp_free_dir));
851 * We can't use bpobj_alloc(), because spa_version() still
852 * returns the old version, and we need a new-version bpobj with
853 * subobj support. So call dmu_object_alloc() directly.
855 obj = dmu_object_alloc(dp->dp_meta_objset, DMU_OT_BPOBJ,
856 SPA_MAXBLOCKSIZE, DMU_OT_BPOBJ_HDR, sizeof (bpobj_phys_t), tx);
857 VERIFY3U(0, ==, zap_add(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
858 DMU_POOL_FREE_BPOBJ, sizeof (uint64_t), 1, &obj, tx));
859 VERIFY3U(0, ==, bpobj_open(&dp->dp_free_bpobj,
860 dp->dp_meta_objset, obj));
862 VERIFY3U(0, ==, dmu_objset_find_spa(dp->dp_spa, NULL,
863 upgrade_dir_clones_cb, tx, DS_FIND_CHILDREN));
867 dsl_pool_create_origin(dsl_pool_t *dp, dmu_tx_t *tx)
872 ASSERT(dmu_tx_is_syncing(tx));
873 ASSERT(dp->dp_origin_snap == NULL);
875 /* create the origin dir, ds, & snap-ds */
876 rw_enter(&dp->dp_config_rwlock, RW_WRITER);
877 dsobj = dsl_dataset_create_sync(dp->dp_root_dir, ORIGIN_DIR_NAME,
879 VERIFY(0 == dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds));
880 dsl_dataset_snapshot_sync(ds, ORIGIN_DIR_NAME, tx);
881 VERIFY(0 == dsl_dataset_hold_obj(dp, ds->ds_phys->ds_prev_snap_obj,
882 dp, &dp->dp_origin_snap));
883 dsl_dataset_rele(ds, FTAG);
884 rw_exit(&dp->dp_config_rwlock);
888 dsl_pool_iput_taskq(dsl_pool_t *dp)
890 return (dp->dp_iput_taskq);
894 * Walk through the pool-wide zap object of temporary snapshot user holds
898 dsl_pool_clean_tmp_userrefs(dsl_pool_t *dp)
902 objset_t *mos = dp->dp_meta_objset;
903 uint64_t zapobj = dp->dp_tmp_userrefs_obj;
907 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS);
909 for (zap_cursor_init(&zc, mos, zapobj);
910 zap_cursor_retrieve(&zc, &za) == 0;
911 zap_cursor_advance(&zc)) {
915 htag = strchr(za.za_name, '-');
918 dsobj = strtonum(za.za_name, NULL);
919 (void) dsl_dataset_user_release_tmp(dp, dsobj, htag, B_FALSE);
921 zap_cursor_fini(&zc);
925 * Create the pool-wide zap object for storing temporary snapshot holds.
928 dsl_pool_user_hold_create_obj(dsl_pool_t *dp, dmu_tx_t *tx)
930 objset_t *mos = dp->dp_meta_objset;
932 ASSERT(dp->dp_tmp_userrefs_obj == 0);
933 ASSERT(dmu_tx_is_syncing(tx));
935 dp->dp_tmp_userrefs_obj = zap_create(mos, DMU_OT_USERREFS,
938 VERIFY(zap_add(mos, DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_TMP_USERREFS,
939 sizeof (uint64_t), 1, &dp->dp_tmp_userrefs_obj, tx) == 0);
943 dsl_pool_user_hold_rele_impl(dsl_pool_t *dp, uint64_t dsobj,
944 const char *tag, uint64_t *now, dmu_tx_t *tx, boolean_t holding)
946 objset_t *mos = dp->dp_meta_objset;
947 uint64_t zapobj = dp->dp_tmp_userrefs_obj;
951 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS);
952 ASSERT(dmu_tx_is_syncing(tx));
955 * If the pool was created prior to SPA_VERSION_USERREFS, the
956 * zap object for temporary holds might not exist yet.
960 dsl_pool_user_hold_create_obj(dp, tx);
961 zapobj = dp->dp_tmp_userrefs_obj;
967 name = kmem_asprintf("%llx-%s", (u_longlong_t)dsobj, tag);
969 error = zap_add(mos, zapobj, name, 8, 1, now, tx);
971 error = zap_remove(mos, zapobj, name, tx);
978 * Add a temporary hold for the given dataset object and tag.
981 dsl_pool_user_hold(dsl_pool_t *dp, uint64_t dsobj, const char *tag,
982 uint64_t *now, dmu_tx_t *tx)
984 return (dsl_pool_user_hold_rele_impl(dp, dsobj, tag, now, tx, B_TRUE));
988 * Release a temporary hold for the given dataset object and tag.
991 dsl_pool_user_release(dsl_pool_t *dp, uint64_t dsobj, const char *tag,
994 return (dsl_pool_user_hold_rele_impl(dp, dsobj, tag, NULL,
998 #if defined(_KERNEL) && defined(HAVE_SPL)
999 module_param(zfs_no_write_throttle, int, 0644);
1000 MODULE_PARM_DESC(zfs_no_write_throttle, "Disable write throttling");
1002 module_param(zfs_write_limit_shift, int, 0444);
1003 MODULE_PARM_DESC(zfs_write_limit_shift, "log2(fraction of memory) per txg");
1005 module_param(zfs_txg_synctime_ms, int, 0644);
1006 MODULE_PARM_DESC(zfs_txg_synctime_ms, "Target milliseconds between txg sync");
1008 module_param(zfs_txg_history, int, 0644);
1009 MODULE_PARM_DESC(zfs_txg_history, "Historic statistics for the last N txgs");
1011 module_param(zfs_write_limit_min, ulong, 0444);
1012 MODULE_PARM_DESC(zfs_write_limit_min, "Min txg write limit");
1014 module_param(zfs_write_limit_max, ulong, 0444);
1015 MODULE_PARM_DESC(zfs_write_limit_max, "Max txg write limit");
1017 module_param(zfs_write_limit_inflated, ulong, 0444);
1018 MODULE_PARM_DESC(zfs_write_limit_inflated, "Inflated txg write limit");
1020 module_param(zfs_write_limit_override, ulong, 0444);
1021 MODULE_PARM_DESC(zfs_write_limit_override, "Override txg write limit");