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) 2012 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>
43 #include <sys/bptree.h>
44 #include <sys/zfeature.h>
45 #include <sys/zil_impl.h>
47 int zfs_no_write_throttle = 0;
48 int zfs_write_limit_shift = 3; /* 1/8th of physical memory */
49 int zfs_txg_synctime_ms = 1000; /* target millisecs to sync a txg */
50 int zfs_txg_history = 60; /* statistics for the last N txgs */
52 unsigned long zfs_write_limit_min = 32 << 20; /* min write limit is 32MB */
53 unsigned long zfs_write_limit_max = 0; /* max data payload per txg */
54 unsigned long zfs_write_limit_inflated = 0;
55 unsigned long zfs_write_limit_override = 0;
57 kmutex_t zfs_write_limit_lock;
59 static pgcnt_t old_physmem = 0;
62 dsl_pool_txg_history_update(kstat_t *ksp, int rw)
64 dsl_pool_t *dp = ksp->ks_private;
68 if (rw == KSTAT_WRITE)
72 kmem_free(ksp->ks_data, ksp->ks_data_size);
74 mutex_enter(&dp->dp_lock);
76 ksp->ks_ndata = dp->dp_txg_history_size;
77 ksp->ks_data_size = dp->dp_txg_history_size * sizeof(kstat_txg_t);
78 if (ksp->ks_data_size > 0)
79 ksp->ks_data = kmem_alloc(ksp->ks_data_size, KM_PUSHPAGE);
81 /* Traversed oldest to youngest for the most readable kstat output */
82 for (th = list_tail(&dp->dp_txg_history); th != NULL;
83 th = list_prev(&dp->dp_txg_history, th)) {
84 mutex_enter(&th->th_lock);
85 ASSERT3S(i + sizeof(kstat_txg_t), <=, ksp->ks_data_size);
86 memcpy(ksp->ks_data + i, &th->th_kstat, sizeof(kstat_txg_t));
87 i += sizeof(kstat_txg_t);
88 mutex_exit(&th->th_lock);
91 mutex_exit(&dp->dp_lock);
97 dsl_pool_txg_history_init(dsl_pool_t *dp, uint64_t txg)
99 char name[KSTAT_STRLEN];
101 list_create(&dp->dp_txg_history, sizeof (txg_history_t),
102 offsetof(txg_history_t, th_link));
103 dsl_pool_txg_history_add(dp, txg);
105 (void) snprintf(name, KSTAT_STRLEN, "txgs-%s", spa_name(dp->dp_spa));
106 dp->dp_txg_kstat = kstat_create("zfs", 0, name, "misc",
107 KSTAT_TYPE_TXG, 0, KSTAT_FLAG_VIRTUAL);
108 if (dp->dp_txg_kstat) {
109 dp->dp_txg_kstat->ks_data = NULL;
110 dp->dp_txg_kstat->ks_private = dp;
111 dp->dp_txg_kstat->ks_update = dsl_pool_txg_history_update;
112 kstat_install(dp->dp_txg_kstat);
117 dsl_pool_txg_history_destroy(dsl_pool_t *dp)
121 if (dp->dp_txg_kstat) {
122 if (dp->dp_txg_kstat->ks_data)
123 kmem_free(dp->dp_txg_kstat->ks_data,
124 dp->dp_txg_kstat->ks_data_size);
126 kstat_delete(dp->dp_txg_kstat);
129 mutex_enter(&dp->dp_lock);
130 while ((th = list_remove_head(&dp->dp_txg_history))) {
131 dp->dp_txg_history_size--;
132 mutex_destroy(&th->th_lock);
133 kmem_free(th, sizeof(txg_history_t));
136 ASSERT3U(dp->dp_txg_history_size, ==, 0);
137 list_destroy(&dp->dp_txg_history);
138 mutex_exit(&dp->dp_lock);
142 dsl_pool_txg_history_add(dsl_pool_t *dp, uint64_t txg)
144 txg_history_t *th, *rm;
146 th = kmem_zalloc(sizeof(txg_history_t), KM_SLEEP);
147 mutex_init(&th->th_lock, NULL, MUTEX_DEFAULT, NULL);
148 th->th_kstat.txg = txg;
149 th->th_kstat.state = TXG_STATE_OPEN;
150 th->th_kstat.birth = gethrtime();
152 mutex_enter(&dp->dp_lock);
154 list_insert_head(&dp->dp_txg_history, th);
155 dp->dp_txg_history_size++;
157 while (dp->dp_txg_history_size > zfs_txg_history) {
158 dp->dp_txg_history_size--;
159 rm = list_remove_tail(&dp->dp_txg_history);
160 mutex_destroy(&rm->th_lock);
161 kmem_free(rm, sizeof(txg_history_t));
164 mutex_exit(&dp->dp_lock);
170 * Traversed youngest to oldest because lookups are only done for open
171 * or syncing txgs which are guaranteed to be at the head of the list.
172 * The txg_history_t structure will be returned locked.
175 dsl_pool_txg_history_get(dsl_pool_t *dp, uint64_t txg)
179 mutex_enter(&dp->dp_lock);
180 for (th = list_head(&dp->dp_txg_history); th != NULL;
181 th = list_next(&dp->dp_txg_history, th)) {
182 if (th->th_kstat.txg == txg) {
183 mutex_enter(&th->th_lock);
187 mutex_exit(&dp->dp_lock);
193 dsl_pool_txg_history_put(txg_history_t *th)
195 mutex_exit(&th->th_lock);
199 dsl_pool_open_special_dir(dsl_pool_t *dp, const char *name, dsl_dir_t **ddp)
204 err = zap_lookup(dp->dp_meta_objset,
205 dp->dp_root_dir->dd_phys->dd_child_dir_zapobj,
206 name, sizeof (obj), 1, &obj);
210 return (dsl_dir_open_obj(dp, obj, name, dp, ddp));
214 dsl_pool_open_impl(spa_t *spa, uint64_t txg)
217 blkptr_t *bp = spa_get_rootblkptr(spa);
219 dp = kmem_zalloc(sizeof (dsl_pool_t), KM_SLEEP);
221 dp->dp_meta_rootbp = *bp;
222 rw_init(&dp->dp_config_rwlock, NULL, RW_DEFAULT, NULL);
223 dp->dp_write_limit = zfs_write_limit_min;
226 txg_list_create(&dp->dp_dirty_datasets,
227 offsetof(dsl_dataset_t, ds_dirty_link));
228 txg_list_create(&dp->dp_dirty_zilogs,
229 offsetof(zilog_t, zl_dirty_link));
230 txg_list_create(&dp->dp_dirty_dirs,
231 offsetof(dsl_dir_t, dd_dirty_link));
232 txg_list_create(&dp->dp_sync_tasks,
233 offsetof(dsl_sync_task_group_t, dstg_node));
235 mutex_init(&dp->dp_lock, NULL, MUTEX_DEFAULT, NULL);
237 dp->dp_iput_taskq = taskq_create("zfs_iput_taskq", 1, minclsyspri,
240 dsl_pool_txg_history_init(dp, txg);
246 dsl_pool_init(spa_t *spa, uint64_t txg, dsl_pool_t **dpp)
249 dsl_pool_t *dp = dsl_pool_open_impl(spa, txg);
251 err = dmu_objset_open_impl(spa, NULL, &dp->dp_meta_rootbp,
252 &dp->dp_meta_objset);
262 dsl_pool_open(dsl_pool_t *dp)
269 rw_enter(&dp->dp_config_rwlock, RW_WRITER);
270 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
271 DMU_POOL_ROOT_DATASET, sizeof (uint64_t), 1,
272 &dp->dp_root_dir_obj);
276 err = dsl_dir_open_obj(dp, dp->dp_root_dir_obj,
277 NULL, dp, &dp->dp_root_dir);
281 err = dsl_pool_open_special_dir(dp, MOS_DIR_NAME, &dp->dp_mos_dir);
285 if (spa_version(dp->dp_spa) >= SPA_VERSION_ORIGIN) {
286 err = dsl_pool_open_special_dir(dp, ORIGIN_DIR_NAME, &dd);
289 err = dsl_dataset_hold_obj(dp, dd->dd_phys->dd_head_dataset_obj,
292 err = dsl_dataset_hold_obj(dp,
293 ds->ds_phys->ds_prev_snap_obj, dp,
294 &dp->dp_origin_snap);
295 dsl_dataset_rele(ds, FTAG);
297 dsl_dir_close(dd, dp);
302 if (spa_version(dp->dp_spa) >= SPA_VERSION_DEADLISTS) {
303 err = dsl_pool_open_special_dir(dp, FREE_DIR_NAME,
308 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
309 DMU_POOL_FREE_BPOBJ, sizeof (uint64_t), 1, &obj);
312 VERIFY3U(0, ==, bpobj_open(&dp->dp_free_bpobj,
313 dp->dp_meta_objset, obj));
316 if (spa_feature_is_active(dp->dp_spa,
317 &spa_feature_table[SPA_FEATURE_ASYNC_DESTROY])) {
318 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
319 DMU_POOL_BPTREE_OBJ, sizeof (uint64_t), 1,
325 if (spa_feature_is_active(dp->dp_spa,
326 &spa_feature_table[SPA_FEATURE_EMPTY_BPOBJ])) {
327 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
328 DMU_POOL_EMPTY_BPOBJ, sizeof (uint64_t), 1,
329 &dp->dp_empty_bpobj);
334 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
335 DMU_POOL_TMP_USERREFS, sizeof (uint64_t), 1,
336 &dp->dp_tmp_userrefs_obj);
342 err = dsl_scan_init(dp, dp->dp_tx.tx_open_txg);
345 rw_exit(&dp->dp_config_rwlock);
350 dsl_pool_close(dsl_pool_t *dp)
352 /* drop our references from dsl_pool_open() */
355 * Since we held the origin_snap from "syncing" context (which
356 * includes pool-opening context), it actually only got a "ref"
357 * and not a hold, so just drop that here.
359 if (dp->dp_origin_snap)
360 dsl_dataset_drop_ref(dp->dp_origin_snap, dp);
362 dsl_dir_close(dp->dp_mos_dir, dp);
364 dsl_dir_close(dp->dp_free_dir, dp);
366 dsl_dir_close(dp->dp_root_dir, dp);
368 bpobj_close(&dp->dp_free_bpobj);
370 /* undo the dmu_objset_open_impl(mos) from dsl_pool_open() */
371 if (dp->dp_meta_objset)
372 dmu_objset_evict(dp->dp_meta_objset);
374 txg_list_destroy(&dp->dp_dirty_datasets);
375 txg_list_destroy(&dp->dp_dirty_zilogs);
376 txg_list_destroy(&dp->dp_sync_tasks);
377 txg_list_destroy(&dp->dp_dirty_dirs);
379 arc_flush(dp->dp_spa);
382 dsl_pool_txg_history_destroy(dp);
383 rw_destroy(&dp->dp_config_rwlock);
384 mutex_destroy(&dp->dp_lock);
385 taskq_destroy(dp->dp_iput_taskq);
387 kmem_free(dp->dp_blkstats, sizeof (zfs_all_blkstats_t));
388 kmem_free(dp, sizeof (dsl_pool_t));
392 dsl_pool_create(spa_t *spa, nvlist_t *zplprops, uint64_t txg)
395 dsl_pool_t *dp = dsl_pool_open_impl(spa, txg);
396 dmu_tx_t *tx = dmu_tx_create_assigned(dp, txg);
401 /* create and open the MOS (meta-objset) */
402 dp->dp_meta_objset = dmu_objset_create_impl(spa,
403 NULL, &dp->dp_meta_rootbp, DMU_OST_META, tx);
405 /* create the pool directory */
406 err = zap_create_claim(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
407 DMU_OT_OBJECT_DIRECTORY, DMU_OT_NONE, 0, tx);
408 ASSERT3U(err, ==, 0);
410 /* Initialize scan structures */
411 VERIFY3U(0, ==, dsl_scan_init(dp, txg));
413 /* create and open the root dir */
414 dp->dp_root_dir_obj = dsl_dir_create_sync(dp, NULL, NULL, tx);
415 VERIFY(0 == dsl_dir_open_obj(dp, dp->dp_root_dir_obj,
416 NULL, dp, &dp->dp_root_dir));
418 /* create and open the meta-objset dir */
419 (void) dsl_dir_create_sync(dp, dp->dp_root_dir, MOS_DIR_NAME, tx);
420 VERIFY(0 == dsl_pool_open_special_dir(dp,
421 MOS_DIR_NAME, &dp->dp_mos_dir));
423 if (spa_version(spa) >= SPA_VERSION_DEADLISTS) {
424 /* create and open the free dir */
425 (void) dsl_dir_create_sync(dp, dp->dp_root_dir,
427 VERIFY(0 == dsl_pool_open_special_dir(dp,
428 FREE_DIR_NAME, &dp->dp_free_dir));
430 /* create and open the free_bplist */
431 obj = bpobj_alloc(dp->dp_meta_objset, SPA_MAXBLOCKSIZE, tx);
432 VERIFY(zap_add(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
433 DMU_POOL_FREE_BPOBJ, sizeof (uint64_t), 1, &obj, tx) == 0);
434 VERIFY3U(0, ==, bpobj_open(&dp->dp_free_bpobj,
435 dp->dp_meta_objset, obj));
438 if (spa_version(spa) >= SPA_VERSION_DSL_SCRUB)
439 dsl_pool_create_origin(dp, tx);
441 /* create the root dataset */
442 obj = dsl_dataset_create_sync_dd(dp->dp_root_dir, NULL, 0, tx);
444 /* create the root objset */
445 VERIFY(0 == dsl_dataset_hold_obj(dp, obj, FTAG, &ds));
446 VERIFY(NULL != (os = dmu_objset_create_impl(dp->dp_spa, ds,
447 dsl_dataset_get_blkptr(ds), DMU_OST_ZFS, tx)));
449 zfs_create_fs(os, kcred, zplprops, tx);
451 dsl_dataset_rele(ds, FTAG);
459 * Account for the meta-objset space in its placeholder dsl_dir.
462 dsl_pool_mos_diduse_space(dsl_pool_t *dp,
463 int64_t used, int64_t comp, int64_t uncomp)
465 ASSERT3U(comp, ==, uncomp); /* it's all metadata */
466 mutex_enter(&dp->dp_lock);
467 dp->dp_mos_used_delta += used;
468 dp->dp_mos_compressed_delta += comp;
469 dp->dp_mos_uncompressed_delta += uncomp;
470 mutex_exit(&dp->dp_lock);
474 deadlist_enqueue_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
476 dsl_deadlist_t *dl = arg;
477 dsl_pool_t *dp = dmu_objset_pool(dl->dl_os);
478 rw_enter(&dp->dp_config_rwlock, RW_READER);
479 dsl_deadlist_insert(dl, bp, tx);
480 rw_exit(&dp->dp_config_rwlock);
485 dsl_pool_sync(dsl_pool_t *dp, uint64_t txg)
491 objset_t *mos = dp->dp_meta_objset;
492 hrtime_t start, write_time;
493 uint64_t data_written;
495 list_t synced_datasets;
497 list_create(&synced_datasets, sizeof (dsl_dataset_t),
498 offsetof(dsl_dataset_t, ds_synced_link));
501 * We need to copy dp_space_towrite() before doing
502 * dsl_sync_task_group_sync(), because
503 * dsl_dataset_snapshot_reserve_space() will increase
504 * dp_space_towrite but not actually write anything.
506 data_written = dp->dp_space_towrite[txg & TXG_MASK];
508 tx = dmu_tx_create_assigned(dp, txg);
510 dp->dp_read_overhead = 0;
513 zio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
514 while ((ds = txg_list_remove(&dp->dp_dirty_datasets, txg))) {
516 * We must not sync any non-MOS datasets twice, because
517 * we may have taken a snapshot of them. However, we
518 * may sync newly-created datasets on pass 2.
520 ASSERT(!list_link_active(&ds->ds_synced_link));
521 list_insert_tail(&synced_datasets, ds);
522 dsl_dataset_sync(ds, zio, tx);
524 DTRACE_PROBE(pool_sync__1setup);
527 write_time = gethrtime() - start;
529 DTRACE_PROBE(pool_sync__2rootzio);
532 * After the data blocks have been written (ensured by the zio_wait()
533 * above), update the user/group space accounting.
535 for (ds = list_head(&synced_datasets); ds;
536 ds = list_next(&synced_datasets, ds))
537 dmu_objset_do_userquota_updates(ds->ds_objset, tx);
540 * Sync the datasets again to push out the changes due to
541 * userspace updates. This must be done before we process the
542 * sync tasks, so that any snapshots will have the correct
543 * user accounting information (and we won't get confused
544 * about which blocks are part of the snapshot).
546 zio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
547 while ((ds = txg_list_remove(&dp->dp_dirty_datasets, txg))) {
548 ASSERT(list_link_active(&ds->ds_synced_link));
549 dmu_buf_rele(ds->ds_dbuf, ds);
550 dsl_dataset_sync(ds, zio, tx);
555 * Now that the datasets have been completely synced, we can
556 * clean up our in-memory structures accumulated while syncing:
558 * - move dead blocks from the pending deadlist to the on-disk deadlist
559 * - clean up zil records
560 * - release hold from dsl_dataset_dirty()
562 while ((ds = list_remove_head(&synced_datasets))) {
563 ASSERTV(objset_t *os = ds->ds_objset);
564 bplist_iterate(&ds->ds_pending_deadlist,
565 deadlist_enqueue_cb, &ds->ds_deadlist, tx);
566 ASSERT(!dmu_objset_is_dirty(os, txg));
567 dmu_buf_rele(ds->ds_dbuf, ds);
571 while ((dd = txg_list_remove(&dp->dp_dirty_dirs, txg)))
572 dsl_dir_sync(dd, tx);
573 write_time += gethrtime() - start;
576 * The MOS's space is accounted for in the pool/$MOS
577 * (dp_mos_dir). We can't modify the mos while we're syncing
578 * it, so we remember the deltas and apply them here.
580 if (dp->dp_mos_used_delta != 0 || dp->dp_mos_compressed_delta != 0 ||
581 dp->dp_mos_uncompressed_delta != 0) {
582 dsl_dir_diduse_space(dp->dp_mos_dir, DD_USED_HEAD,
583 dp->dp_mos_used_delta,
584 dp->dp_mos_compressed_delta,
585 dp->dp_mos_uncompressed_delta, tx);
586 dp->dp_mos_used_delta = 0;
587 dp->dp_mos_compressed_delta = 0;
588 dp->dp_mos_uncompressed_delta = 0;
592 if (list_head(&mos->os_dirty_dnodes[txg & TXG_MASK]) != NULL ||
593 list_head(&mos->os_free_dnodes[txg & TXG_MASK]) != NULL) {
594 zio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
595 dmu_objset_sync(mos, zio, tx);
598 dprintf_bp(&dp->dp_meta_rootbp, "meta objset rootbp is %s", "");
599 spa_set_rootblkptr(dp->dp_spa, &dp->dp_meta_rootbp);
601 write_time += gethrtime() - start;
602 DTRACE_PROBE2(pool_sync__4io, hrtime_t, write_time,
603 hrtime_t, dp->dp_read_overhead);
604 write_time -= dp->dp_read_overhead;
607 * If we modify a dataset in the same txg that we want to destroy it,
608 * its dsl_dir's dd_dbuf will be dirty, and thus have a hold on it.
609 * dsl_dir_destroy_check() will fail if there are unexpected holds.
610 * Therefore, we want to sync the MOS (thus syncing the dd_dbuf
611 * and clearing the hold on it) before we process the sync_tasks.
612 * The MOS data dirtied by the sync_tasks will be synced on the next
615 DTRACE_PROBE(pool_sync__3task);
616 if (!txg_list_empty(&dp->dp_sync_tasks, txg)) {
617 dsl_sync_task_group_t *dstg;
619 * No more sync tasks should have been added while we
622 ASSERT(spa_sync_pass(dp->dp_spa) == 1);
623 while ((dstg = txg_list_remove(&dp->dp_sync_tasks, txg)))
624 dsl_sync_task_group_sync(dstg, tx);
629 dp->dp_space_towrite[txg & TXG_MASK] = 0;
630 ASSERT(dp->dp_tempreserved[txg & TXG_MASK] == 0);
633 * If the write limit max has not been explicitly set, set it
634 * to a fraction of available physical memory (default 1/8th).
635 * Note that we must inflate the limit because the spa
636 * inflates write sizes to account for data replication.
637 * Check this each sync phase to catch changing memory size.
639 if (physmem != old_physmem && zfs_write_limit_shift) {
640 mutex_enter(&zfs_write_limit_lock);
641 old_physmem = physmem;
642 zfs_write_limit_max = ptob(physmem) >> zfs_write_limit_shift;
643 zfs_write_limit_inflated = MAX(zfs_write_limit_min,
644 spa_get_asize(dp->dp_spa, zfs_write_limit_max));
645 mutex_exit(&zfs_write_limit_lock);
649 * Attempt to keep the sync time consistent by adjusting the
650 * amount of write traffic allowed into each transaction group.
651 * Weight the throughput calculation towards the current value:
652 * thru = 3/4 old_thru + 1/4 new_thru
654 * Note: write_time is in nanosecs, so write_time/MICROSEC
657 ASSERT(zfs_write_limit_min > 0);
658 if (data_written > zfs_write_limit_min / 8 && write_time > MICROSEC) {
659 uint64_t throughput = data_written / (write_time / MICROSEC);
661 if (dp->dp_throughput)
662 dp->dp_throughput = throughput / 4 +
663 3 * dp->dp_throughput / 4;
665 dp->dp_throughput = throughput;
666 dp->dp_write_limit = MIN(zfs_write_limit_inflated,
667 MAX(zfs_write_limit_min,
668 dp->dp_throughput * zfs_txg_synctime_ms));
673 dsl_pool_sync_done(dsl_pool_t *dp, uint64_t txg)
678 while ((zilog = txg_list_remove(&dp->dp_dirty_zilogs, txg))) {
679 ds = dmu_objset_ds(zilog->zl_os);
680 zil_clean(zilog, txg);
681 ASSERT(!dmu_objset_is_dirty(zilog->zl_os, txg));
682 dmu_buf_rele(ds->ds_dbuf, zilog);
684 ASSERT(!dmu_objset_is_dirty(dp->dp_meta_objset, txg));
688 * TRUE if the current thread is the tx_sync_thread or if we
689 * are being called from SPA context during pool initialization.
692 dsl_pool_sync_context(dsl_pool_t *dp)
694 return (curthread == dp->dp_tx.tx_sync_thread ||
695 spa_is_initializing(dp->dp_spa));
699 dsl_pool_adjustedsize(dsl_pool_t *dp, boolean_t netfree)
701 uint64_t space, resv;
704 * Reserve about 1.6% (1/64), or at least 32MB, for allocation
706 * XXX The intent log is not accounted for, so it must fit
709 * If we're trying to assess whether it's OK to do a free,
710 * cut the reservation in half to allow forward progress
711 * (e.g. make it possible to rm(1) files from a full pool).
713 space = spa_get_dspace(dp->dp_spa);
714 resv = MAX(space >> 6, SPA_MINDEVSIZE >> 1);
718 return (space - resv);
722 dsl_pool_tempreserve_space(dsl_pool_t *dp, uint64_t space, dmu_tx_t *tx)
724 uint64_t reserved = 0;
725 uint64_t write_limit = (zfs_write_limit_override ?
726 zfs_write_limit_override : dp->dp_write_limit);
728 if (zfs_no_write_throttle) {
729 atomic_add_64(&dp->dp_tempreserved[tx->tx_txg & TXG_MASK],
735 * Check to see if we have exceeded the maximum allowed IO for
736 * this transaction group. We can do this without locks since
737 * a little slop here is ok. Note that we do the reserved check
738 * with only half the requested reserve: this is because the
739 * reserve requests are worst-case, and we really don't want to
740 * throttle based off of worst-case estimates.
742 if (write_limit > 0) {
743 reserved = dp->dp_space_towrite[tx->tx_txg & TXG_MASK]
744 + dp->dp_tempreserved[tx->tx_txg & TXG_MASK] / 2;
746 if (reserved && reserved > write_limit) {
747 DMU_TX_STAT_BUMP(dmu_tx_write_limit);
752 atomic_add_64(&dp->dp_tempreserved[tx->tx_txg & TXG_MASK], space);
755 * If this transaction group is over 7/8ths capacity, delay
756 * the caller 1 clock tick. This will slow down the "fill"
757 * rate until the sync process can catch up with us.
759 if (reserved && reserved > (write_limit - (write_limit >> 3)))
760 txg_delay(dp, tx->tx_txg, 1);
766 dsl_pool_tempreserve_clear(dsl_pool_t *dp, int64_t space, dmu_tx_t *tx)
768 ASSERT(dp->dp_tempreserved[tx->tx_txg & TXG_MASK] >= space);
769 atomic_add_64(&dp->dp_tempreserved[tx->tx_txg & TXG_MASK], -space);
773 dsl_pool_memory_pressure(dsl_pool_t *dp)
775 uint64_t space_inuse = 0;
778 if (dp->dp_write_limit == zfs_write_limit_min)
781 for (i = 0; i < TXG_SIZE; i++) {
782 space_inuse += dp->dp_space_towrite[i];
783 space_inuse += dp->dp_tempreserved[i];
785 dp->dp_write_limit = MAX(zfs_write_limit_min,
786 MIN(dp->dp_write_limit, space_inuse / 4));
790 dsl_pool_willuse_space(dsl_pool_t *dp, int64_t space, dmu_tx_t *tx)
793 mutex_enter(&dp->dp_lock);
794 dp->dp_space_towrite[tx->tx_txg & TXG_MASK] += space;
795 mutex_exit(&dp->dp_lock);
801 upgrade_clones_cb(spa_t *spa, uint64_t dsobj, const char *dsname, void *arg)
804 dsl_dataset_t *ds, *prev = NULL;
806 dsl_pool_t *dp = spa_get_dsl(spa);
808 err = dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds);
812 while (ds->ds_phys->ds_prev_snap_obj != 0) {
813 err = dsl_dataset_hold_obj(dp, ds->ds_phys->ds_prev_snap_obj,
816 dsl_dataset_rele(ds, FTAG);
820 if (prev->ds_phys->ds_next_snap_obj != ds->ds_object)
822 dsl_dataset_rele(ds, FTAG);
828 prev = dp->dp_origin_snap;
831 * The $ORIGIN can't have any data, or the accounting
834 ASSERT(prev->ds_phys->ds_bp.blk_birth == 0);
836 /* The origin doesn't get attached to itself */
837 if (ds->ds_object == prev->ds_object) {
838 dsl_dataset_rele(ds, FTAG);
842 dmu_buf_will_dirty(ds->ds_dbuf, tx);
843 ds->ds_phys->ds_prev_snap_obj = prev->ds_object;
844 ds->ds_phys->ds_prev_snap_txg = prev->ds_phys->ds_creation_txg;
846 dmu_buf_will_dirty(ds->ds_dir->dd_dbuf, tx);
847 ds->ds_dir->dd_phys->dd_origin_obj = prev->ds_object;
849 dmu_buf_will_dirty(prev->ds_dbuf, tx);
850 prev->ds_phys->ds_num_children++;
852 if (ds->ds_phys->ds_next_snap_obj == 0) {
853 ASSERT(ds->ds_prev == NULL);
854 VERIFY(0 == dsl_dataset_hold_obj(dp,
855 ds->ds_phys->ds_prev_snap_obj, ds, &ds->ds_prev));
859 ASSERT(ds->ds_dir->dd_phys->dd_origin_obj == prev->ds_object);
860 ASSERT(ds->ds_phys->ds_prev_snap_obj == prev->ds_object);
862 if (prev->ds_phys->ds_next_clones_obj == 0) {
863 dmu_buf_will_dirty(prev->ds_dbuf, tx);
864 prev->ds_phys->ds_next_clones_obj =
865 zap_create(dp->dp_meta_objset,
866 DMU_OT_NEXT_CLONES, DMU_OT_NONE, 0, tx);
868 VERIFY(0 == zap_add_int(dp->dp_meta_objset,
869 prev->ds_phys->ds_next_clones_obj, ds->ds_object, tx));
871 dsl_dataset_rele(ds, FTAG);
872 if (prev != dp->dp_origin_snap)
873 dsl_dataset_rele(prev, FTAG);
878 dsl_pool_upgrade_clones(dsl_pool_t *dp, dmu_tx_t *tx)
880 ASSERT(dmu_tx_is_syncing(tx));
881 ASSERT(dp->dp_origin_snap != NULL);
883 VERIFY3U(0, ==, dmu_objset_find_spa(dp->dp_spa, NULL, upgrade_clones_cb,
884 tx, DS_FIND_CHILDREN));
889 upgrade_dir_clones_cb(spa_t *spa, uint64_t dsobj, const char *dsname, void *arg)
893 dsl_pool_t *dp = spa_get_dsl(spa);
894 objset_t *mos = dp->dp_meta_objset;
896 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds));
898 if (ds->ds_dir->dd_phys->dd_origin_obj) {
899 dsl_dataset_t *origin;
901 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp,
902 ds->ds_dir->dd_phys->dd_origin_obj, FTAG, &origin));
904 if (origin->ds_dir->dd_phys->dd_clones == 0) {
905 dmu_buf_will_dirty(origin->ds_dir->dd_dbuf, tx);
906 origin->ds_dir->dd_phys->dd_clones = zap_create(mos,
907 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx);
910 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset,
911 origin->ds_dir->dd_phys->dd_clones, dsobj, tx));
913 dsl_dataset_rele(origin, FTAG);
916 dsl_dataset_rele(ds, FTAG);
921 dsl_pool_upgrade_dir_clones(dsl_pool_t *dp, dmu_tx_t *tx)
925 ASSERT(dmu_tx_is_syncing(tx));
927 (void) dsl_dir_create_sync(dp, dp->dp_root_dir, FREE_DIR_NAME, tx);
928 VERIFY(0 == dsl_pool_open_special_dir(dp,
929 FREE_DIR_NAME, &dp->dp_free_dir));
932 * We can't use bpobj_alloc(), because spa_version() still
933 * returns the old version, and we need a new-version bpobj with
934 * subobj support. So call dmu_object_alloc() directly.
936 obj = dmu_object_alloc(dp->dp_meta_objset, DMU_OT_BPOBJ,
937 SPA_MAXBLOCKSIZE, DMU_OT_BPOBJ_HDR, sizeof (bpobj_phys_t), tx);
938 VERIFY3U(0, ==, zap_add(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
939 DMU_POOL_FREE_BPOBJ, sizeof (uint64_t), 1, &obj, tx));
940 VERIFY3U(0, ==, bpobj_open(&dp->dp_free_bpobj,
941 dp->dp_meta_objset, obj));
943 VERIFY3U(0, ==, dmu_objset_find_spa(dp->dp_spa, NULL,
944 upgrade_dir_clones_cb, tx, DS_FIND_CHILDREN));
948 dsl_pool_create_origin(dsl_pool_t *dp, dmu_tx_t *tx)
953 ASSERT(dmu_tx_is_syncing(tx));
954 ASSERT(dp->dp_origin_snap == NULL);
956 /* create the origin dir, ds, & snap-ds */
957 rw_enter(&dp->dp_config_rwlock, RW_WRITER);
958 dsobj = dsl_dataset_create_sync(dp->dp_root_dir, ORIGIN_DIR_NAME,
960 VERIFY(0 == dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds));
961 dsl_dataset_snapshot_sync(ds, ORIGIN_DIR_NAME, tx);
962 VERIFY(0 == dsl_dataset_hold_obj(dp, ds->ds_phys->ds_prev_snap_obj,
963 dp, &dp->dp_origin_snap));
964 dsl_dataset_rele(ds, FTAG);
965 rw_exit(&dp->dp_config_rwlock);
969 dsl_pool_iput_taskq(dsl_pool_t *dp)
971 return (dp->dp_iput_taskq);
975 * Walk through the pool-wide zap object of temporary snapshot user holds
979 dsl_pool_clean_tmp_userrefs(dsl_pool_t *dp)
983 objset_t *mos = dp->dp_meta_objset;
984 uint64_t zapobj = dp->dp_tmp_userrefs_obj;
988 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS);
990 for (zap_cursor_init(&zc, mos, zapobj);
991 zap_cursor_retrieve(&zc, &za) == 0;
992 zap_cursor_advance(&zc)) {
996 htag = strchr(za.za_name, '-');
999 dsobj = strtonum(za.za_name, NULL);
1000 (void) dsl_dataset_user_release_tmp(dp, dsobj, htag, B_FALSE);
1002 zap_cursor_fini(&zc);
1006 * Create the pool-wide zap object for storing temporary snapshot holds.
1009 dsl_pool_user_hold_create_obj(dsl_pool_t *dp, dmu_tx_t *tx)
1011 objset_t *mos = dp->dp_meta_objset;
1013 ASSERT(dp->dp_tmp_userrefs_obj == 0);
1014 ASSERT(dmu_tx_is_syncing(tx));
1016 dp->dp_tmp_userrefs_obj = zap_create_link(mos, DMU_OT_USERREFS,
1017 DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_TMP_USERREFS, tx);
1021 dsl_pool_user_hold_rele_impl(dsl_pool_t *dp, uint64_t dsobj,
1022 const char *tag, uint64_t *now, dmu_tx_t *tx, boolean_t holding)
1024 objset_t *mos = dp->dp_meta_objset;
1025 uint64_t zapobj = dp->dp_tmp_userrefs_obj;
1029 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS);
1030 ASSERT(dmu_tx_is_syncing(tx));
1033 * If the pool was created prior to SPA_VERSION_USERREFS, the
1034 * zap object for temporary holds might not exist yet.
1038 dsl_pool_user_hold_create_obj(dp, tx);
1039 zapobj = dp->dp_tmp_userrefs_obj;
1045 name = kmem_asprintf("%llx-%s", (u_longlong_t)dsobj, tag);
1047 error = zap_add(mos, zapobj, name, 8, 1, now, tx);
1049 error = zap_remove(mos, zapobj, name, tx);
1056 * Add a temporary hold for the given dataset object and tag.
1059 dsl_pool_user_hold(dsl_pool_t *dp, uint64_t dsobj, const char *tag,
1060 uint64_t *now, dmu_tx_t *tx)
1062 return (dsl_pool_user_hold_rele_impl(dp, dsobj, tag, now, tx, B_TRUE));
1066 * Release a temporary hold for the given dataset object and tag.
1069 dsl_pool_user_release(dsl_pool_t *dp, uint64_t dsobj, const char *tag,
1072 return (dsl_pool_user_hold_rele_impl(dp, dsobj, tag, NULL,
1076 #if defined(_KERNEL) && defined(HAVE_SPL)
1077 module_param(zfs_no_write_throttle, int, 0644);
1078 MODULE_PARM_DESC(zfs_no_write_throttle, "Disable write throttling");
1080 module_param(zfs_write_limit_shift, int, 0444);
1081 MODULE_PARM_DESC(zfs_write_limit_shift, "log2(fraction of memory) per txg");
1083 module_param(zfs_txg_synctime_ms, int, 0644);
1084 MODULE_PARM_DESC(zfs_txg_synctime_ms, "Target milliseconds between txg sync");
1086 module_param(zfs_txg_history, int, 0644);
1087 MODULE_PARM_DESC(zfs_txg_history, "Historic statistics for the last N txgs");
1089 module_param(zfs_write_limit_min, ulong, 0444);
1090 MODULE_PARM_DESC(zfs_write_limit_min, "Min txg write limit");
1092 module_param(zfs_write_limit_max, ulong, 0444);
1093 MODULE_PARM_DESC(zfs_write_limit_max, "Max txg write limit");
1095 module_param(zfs_write_limit_inflated, ulong, 0444);
1096 MODULE_PARM_DESC(zfs_write_limit_inflated, "Inflated txg write limit");
1098 module_param(zfs_write_limit_override, ulong, 0444);
1099 MODULE_PARM_DESC(zfs_write_limit_override, "Override txg write limit");