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, 2017 by Delphix. All rights reserved.
24 * Copyright (c) 2013 Steven Hartland. All rights reserved.
25 * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
26 * Copyright (c) 2014 Integros [integros.com]
27 * Copyright 2016 Nexenta Systems, Inc. All rights reserved.
30 #include <sys/dsl_pool.h>
31 #include <sys/dsl_dataset.h>
32 #include <sys/dsl_prop.h>
33 #include <sys/dsl_dir.h>
34 #include <sys/dsl_synctask.h>
35 #include <sys/dsl_scan.h>
36 #include <sys/dnode.h>
37 #include <sys/dmu_tx.h>
38 #include <sys/dmu_objset.h>
42 #include <sys/zfs_context.h>
43 #include <sys/fs/zfs.h>
44 #include <sys/zfs_znode.h>
45 #include <sys/spa_impl.h>
46 #include <sys/dsl_deadlist.h>
47 #include <sys/vdev_impl.h>
48 #include <sys/metaslab_impl.h>
49 #include <sys/bptree.h>
50 #include <sys/zfeature.h>
51 #include <sys/zil_impl.h>
52 #include <sys/dsl_userhold.h>
58 * ZFS must limit the rate of incoming writes to the rate at which it is able
59 * to sync data modifications to the backend storage. Throttling by too much
60 * creates an artificial limit; throttling by too little can only be sustained
61 * for short periods and would lead to highly lumpy performance. On a per-pool
62 * basis, ZFS tracks the amount of modified (dirty) data. As operations change
63 * data, the amount of dirty data increases; as ZFS syncs out data, the amount
64 * of dirty data decreases. When the amount of dirty data exceeds a
65 * predetermined threshold further modifications are blocked until the amount
66 * of dirty data decreases (as data is synced out).
68 * The limit on dirty data is tunable, and should be adjusted according to
69 * both the IO capacity and available memory of the system. The larger the
70 * window, the more ZFS is able to aggregate and amortize metadata (and data)
71 * changes. However, memory is a limited resource, and allowing for more dirty
72 * data comes at the cost of keeping other useful data in memory (for example
73 * ZFS data cached by the ARC).
77 * As buffers are modified dsl_pool_willuse_space() increments both the per-
78 * txg (dp_dirty_pertxg[]) and poolwide (dp_dirty_total) accounting of
79 * dirty space used; dsl_pool_dirty_space() decrements those values as data
80 * is synced out from dsl_pool_sync(). While only the poolwide value is
81 * relevant, the per-txg value is useful for debugging. The tunable
82 * zfs_dirty_data_max determines the dirty space limit. Once that value is
83 * exceeded, new writes are halted until space frees up.
85 * The zfs_dirty_data_sync tunable dictates the threshold at which we
86 * ensure that there is a txg syncing (see the comment in txg.c for a full
87 * description of transaction group stages).
89 * The IO scheduler uses both the dirty space limit and current amount of
90 * dirty data as inputs. Those values affect the number of concurrent IOs ZFS
91 * issues. See the comment in vdev_queue.c for details of the IO scheduler.
93 * The delay is also calculated based on the amount of dirty data. See the
94 * comment above dmu_tx_delay() for details.
98 * zfs_dirty_data_max will be set to zfs_dirty_data_max_percent% of all memory,
99 * capped at zfs_dirty_data_max_max. It can also be overridden in /etc/system.
101 uint64_t zfs_dirty_data_max
;
102 uint64_t zfs_dirty_data_max_max
= 4ULL * 1024 * 1024 * 1024;
103 int zfs_dirty_data_max_percent
= 10;
106 * If there is at least this much dirty data, push out a txg.
108 uint64_t zfs_dirty_data_sync
= 64 * 1024 * 1024;
111 * Once there is this amount of dirty data, the dmu_tx_delay() will kick in
112 * and delay each transaction.
113 * This value should be >= zfs_vdev_async_write_active_max_dirty_percent.
115 int zfs_delay_min_dirty_percent
= 60;
118 * This controls how quickly the delay approaches infinity.
119 * Larger values cause it to delay more for a given amount of dirty data.
120 * Therefore larger values will cause there to be less dirty data for a
123 * For the smoothest delay, this value should be about 1 billion divided
124 * by the maximum number of operations per second. This will smoothly
125 * handle between 10x and 1/10th this number.
127 * Note: zfs_delay_scale * zfs_dirty_data_max must be < 2^64, due to the
128 * multiply in dmu_tx_delay().
130 uint64_t zfs_delay_scale
= 1000 * 1000 * 1000 / 2000;
133 * This determines the number of threads used by the dp_sync_taskq.
135 int zfs_sync_taskq_batch_pct
= 75;
138 * These tunables determine the behavior of how zil_itxg_clean() is
139 * called via zil_clean() in the context of spa_sync(). When an itxg
140 * list needs to be cleaned, TQ_NOSLEEP will be used when dispatching.
141 * If the dispatch fails, the call to zil_itxg_clean() will occur
142 * synchronously in the context of spa_sync(), which can negatively
143 * impact the performance of spa_sync() (e.g. in the case of the itxg
144 * list having a large number of itxs that needs to be cleaned).
146 * Thus, these tunables can be used to manipulate the behavior of the
147 * taskq used by zil_clean(); they determine the number of taskq entries
148 * that are pre-populated when the taskq is first created (via the
149 * "zfs_zil_clean_taskq_minalloc" tunable) and the maximum number of
150 * taskq entries that are cached after an on-demand allocation (via the
151 * "zfs_zil_clean_taskq_maxalloc").
153 * The idea being, we want to try reasonably hard to ensure there will
154 * already be a taskq entry pre-allocated by the time that it is needed
155 * by zil_clean(). This way, we can avoid the possibility of an
156 * on-demand allocation of a new taskq entry from failing, which would
157 * result in zil_itxg_clean() being called synchronously from zil_clean()
158 * (which can adversely affect performance of spa_sync()).
160 * Additionally, the number of threads used by the taskq can be
161 * configured via the "zfs_zil_clean_taskq_nthr_pct" tunable.
163 int zfs_zil_clean_taskq_nthr_pct
= 100;
164 int zfs_zil_clean_taskq_minalloc
= 1024;
165 int zfs_zil_clean_taskq_maxalloc
= 1024 * 1024;
168 dsl_pool_open_special_dir(dsl_pool_t
*dp
, const char *name
, dsl_dir_t
**ddp
)
173 err
= zap_lookup(dp
->dp_meta_objset
,
174 dsl_dir_phys(dp
->dp_root_dir
)->dd_child_dir_zapobj
,
175 name
, sizeof (obj
), 1, &obj
);
179 return (dsl_dir_hold_obj(dp
, obj
, name
, dp
, ddp
));
183 dsl_pool_open_impl(spa_t
*spa
, uint64_t txg
)
186 blkptr_t
*bp
= spa_get_rootblkptr(spa
);
188 dp
= kmem_zalloc(sizeof (dsl_pool_t
), KM_SLEEP
);
190 dp
->dp_meta_rootbp
= *bp
;
191 rrw_init(&dp
->dp_config_rwlock
, B_TRUE
);
194 txg_list_create(&dp
->dp_dirty_datasets
, spa
,
195 offsetof(dsl_dataset_t
, ds_dirty_link
));
196 txg_list_create(&dp
->dp_dirty_zilogs
, spa
,
197 offsetof(zilog_t
, zl_dirty_link
));
198 txg_list_create(&dp
->dp_dirty_dirs
, spa
,
199 offsetof(dsl_dir_t
, dd_dirty_link
));
200 txg_list_create(&dp
->dp_sync_tasks
, spa
,
201 offsetof(dsl_sync_task_t
, dst_node
));
202 txg_list_create(&dp
->dp_early_sync_tasks
, spa
,
203 offsetof(dsl_sync_task_t
, dst_node
));
205 dp
->dp_sync_taskq
= taskq_create("dp_sync_taskq",
206 zfs_sync_taskq_batch_pct
, minclsyspri
, 1, INT_MAX
,
207 TASKQ_THREADS_CPU_PCT
);
209 dp
->dp_zil_clean_taskq
= taskq_create("dp_zil_clean_taskq",
210 zfs_zil_clean_taskq_nthr_pct
, minclsyspri
,
211 zfs_zil_clean_taskq_minalloc
,
212 zfs_zil_clean_taskq_maxalloc
,
213 TASKQ_PREPOPULATE
| TASKQ_THREADS_CPU_PCT
);
215 mutex_init(&dp
->dp_lock
, NULL
, MUTEX_DEFAULT
, NULL
);
216 cv_init(&dp
->dp_spaceavail_cv
, NULL
, CV_DEFAULT
, NULL
);
218 dp
->dp_vnrele_taskq
= taskq_create("zfs_vn_rele_taskq", 1, minclsyspri
,
225 dsl_pool_init(spa_t
*spa
, uint64_t txg
, dsl_pool_t
**dpp
)
228 dsl_pool_t
*dp
= dsl_pool_open_impl(spa
, txg
);
230 err
= dmu_objset_open_impl(spa
, NULL
, &dp
->dp_meta_rootbp
,
231 &dp
->dp_meta_objset
);
241 dsl_pool_open(dsl_pool_t
*dp
)
248 rrw_enter(&dp
->dp_config_rwlock
, RW_WRITER
, FTAG
);
249 err
= zap_lookup(dp
->dp_meta_objset
, DMU_POOL_DIRECTORY_OBJECT
,
250 DMU_POOL_ROOT_DATASET
, sizeof (uint64_t), 1,
251 &dp
->dp_root_dir_obj
);
255 err
= dsl_dir_hold_obj(dp
, dp
->dp_root_dir_obj
,
256 NULL
, dp
, &dp
->dp_root_dir
);
260 err
= dsl_pool_open_special_dir(dp
, MOS_DIR_NAME
, &dp
->dp_mos_dir
);
264 if (spa_version(dp
->dp_spa
) >= SPA_VERSION_ORIGIN
) {
265 err
= dsl_pool_open_special_dir(dp
, ORIGIN_DIR_NAME
, &dd
);
268 err
= dsl_dataset_hold_obj(dp
,
269 dsl_dir_phys(dd
)->dd_head_dataset_obj
, FTAG
, &ds
);
271 err
= dsl_dataset_hold_obj(dp
,
272 dsl_dataset_phys(ds
)->ds_prev_snap_obj
, dp
,
273 &dp
->dp_origin_snap
);
274 dsl_dataset_rele(ds
, FTAG
);
276 dsl_dir_rele(dd
, dp
);
281 if (spa_version(dp
->dp_spa
) >= SPA_VERSION_DEADLISTS
) {
282 err
= dsl_pool_open_special_dir(dp
, FREE_DIR_NAME
,
287 err
= zap_lookup(dp
->dp_meta_objset
, DMU_POOL_DIRECTORY_OBJECT
,
288 DMU_POOL_FREE_BPOBJ
, sizeof (uint64_t), 1, &obj
);
291 VERIFY0(bpobj_open(&dp
->dp_free_bpobj
,
292 dp
->dp_meta_objset
, obj
));
295 if (spa_feature_is_active(dp
->dp_spa
, SPA_FEATURE_OBSOLETE_COUNTS
)) {
296 err
= zap_lookup(dp
->dp_meta_objset
, DMU_POOL_DIRECTORY_OBJECT
,
297 DMU_POOL_OBSOLETE_BPOBJ
, sizeof (uint64_t), 1, &obj
);
299 VERIFY0(bpobj_open(&dp
->dp_obsolete_bpobj
,
300 dp
->dp_meta_objset
, obj
));
301 } else if (err
== ENOENT
) {
303 * We might not have created the remap bpobj yet.
312 * Note: errors ignored, because the these special dirs, used for
313 * space accounting, are only created on demand.
315 (void) dsl_pool_open_special_dir(dp
, LEAK_DIR_NAME
,
318 if (spa_feature_is_active(dp
->dp_spa
, SPA_FEATURE_ASYNC_DESTROY
)) {
319 err
= zap_lookup(dp
->dp_meta_objset
, DMU_POOL_DIRECTORY_OBJECT
,
320 DMU_POOL_BPTREE_OBJ
, sizeof (uint64_t), 1,
326 if (spa_feature_is_active(dp
->dp_spa
, 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 rrw_exit(&dp
->dp_config_rwlock
, FTAG
);
350 dsl_pool_close(dsl_pool_t
*dp
)
353 * 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
!= NULL
)
360 dsl_dataset_rele(dp
->dp_origin_snap
, dp
);
361 if (dp
->dp_mos_dir
!= NULL
)
362 dsl_dir_rele(dp
->dp_mos_dir
, dp
);
363 if (dp
->dp_free_dir
!= NULL
)
364 dsl_dir_rele(dp
->dp_free_dir
, dp
);
365 if (dp
->dp_leak_dir
!= NULL
)
366 dsl_dir_rele(dp
->dp_leak_dir
, dp
);
367 if (dp
->dp_root_dir
!= NULL
)
368 dsl_dir_rele(dp
->dp_root_dir
, dp
);
370 bpobj_close(&dp
->dp_free_bpobj
);
371 bpobj_close(&dp
->dp_obsolete_bpobj
);
373 /* undo the dmu_objset_open_impl(mos) from dsl_pool_open() */
374 if (dp
->dp_meta_objset
!= NULL
)
375 dmu_objset_evict(dp
->dp_meta_objset
);
377 txg_list_destroy(&dp
->dp_dirty_datasets
);
378 txg_list_destroy(&dp
->dp_dirty_zilogs
);
379 txg_list_destroy(&dp
->dp_sync_tasks
);
380 txg_list_destroy(&dp
->dp_early_sync_tasks
);
381 txg_list_destroy(&dp
->dp_dirty_dirs
);
383 taskq_destroy(dp
->dp_zil_clean_taskq
);
384 taskq_destroy(dp
->dp_sync_taskq
);
387 * We can't set retry to TRUE since we're explicitly specifying
388 * a spa to flush. This is good enough; any missed buffers for
389 * this spa won't cause trouble, and they'll eventually fall
390 * out of the ARC just like any other unused buffer.
392 arc_flush(dp
->dp_spa
, FALSE
);
396 dmu_buf_user_evict_wait();
398 rrw_destroy(&dp
->dp_config_rwlock
);
399 mutex_destroy(&dp
->dp_lock
);
400 taskq_destroy(dp
->dp_vnrele_taskq
);
401 if (dp
->dp_blkstats
!= NULL
)
402 kmem_free(dp
->dp_blkstats
, sizeof (zfs_all_blkstats_t
));
403 kmem_free(dp
, sizeof (dsl_pool_t
));
407 dsl_pool_create_obsolete_bpobj(dsl_pool_t
*dp
, dmu_tx_t
*tx
)
411 * Currently, we only create the obsolete_bpobj where there are
412 * indirect vdevs with referenced mappings.
414 ASSERT(spa_feature_is_active(dp
->dp_spa
, SPA_FEATURE_DEVICE_REMOVAL
));
415 /* create and open the obsolete_bpobj */
416 obj
= bpobj_alloc(dp
->dp_meta_objset
, SPA_OLD_MAXBLOCKSIZE
, tx
);
417 VERIFY0(bpobj_open(&dp
->dp_obsolete_bpobj
, dp
->dp_meta_objset
, obj
));
418 VERIFY0(zap_add(dp
->dp_meta_objset
, DMU_POOL_DIRECTORY_OBJECT
,
419 DMU_POOL_OBSOLETE_BPOBJ
, sizeof (uint64_t), 1, &obj
, tx
));
420 spa_feature_incr(dp
->dp_spa
, SPA_FEATURE_OBSOLETE_COUNTS
, tx
);
424 dsl_pool_destroy_obsolete_bpobj(dsl_pool_t
*dp
, dmu_tx_t
*tx
)
426 spa_feature_decr(dp
->dp_spa
, SPA_FEATURE_OBSOLETE_COUNTS
, tx
);
427 VERIFY0(zap_remove(dp
->dp_meta_objset
,
428 DMU_POOL_DIRECTORY_OBJECT
,
429 DMU_POOL_OBSOLETE_BPOBJ
, tx
));
430 bpobj_free(dp
->dp_meta_objset
,
431 dp
->dp_obsolete_bpobj
.bpo_object
, tx
);
432 bpobj_close(&dp
->dp_obsolete_bpobj
);
436 dsl_pool_create(spa_t
*spa
, nvlist_t
*zplprops
, uint64_t txg
)
439 dsl_pool_t
*dp
= dsl_pool_open_impl(spa
, txg
);
440 dmu_tx_t
*tx
= dmu_tx_create_assigned(dp
, txg
);
444 rrw_enter(&dp
->dp_config_rwlock
, RW_WRITER
, FTAG
);
446 /* create and open the MOS (meta-objset) */
447 dp
->dp_meta_objset
= dmu_objset_create_impl(spa
,
448 NULL
, &dp
->dp_meta_rootbp
, DMU_OST_META
, tx
);
450 /* create the pool directory */
451 err
= zap_create_claim(dp
->dp_meta_objset
, DMU_POOL_DIRECTORY_OBJECT
,
452 DMU_OT_OBJECT_DIRECTORY
, DMU_OT_NONE
, 0, tx
);
455 /* Initialize scan structures */
456 VERIFY0(dsl_scan_init(dp
, txg
));
458 /* create and open the root dir */
459 dp
->dp_root_dir_obj
= dsl_dir_create_sync(dp
, NULL
, NULL
, tx
);
460 VERIFY0(dsl_dir_hold_obj(dp
, dp
->dp_root_dir_obj
,
461 NULL
, dp
, &dp
->dp_root_dir
));
463 /* create and open the meta-objset dir */
464 (void) dsl_dir_create_sync(dp
, dp
->dp_root_dir
, MOS_DIR_NAME
, tx
);
465 VERIFY0(dsl_pool_open_special_dir(dp
,
466 MOS_DIR_NAME
, &dp
->dp_mos_dir
));
468 if (spa_version(spa
) >= SPA_VERSION_DEADLISTS
) {
469 /* create and open the free dir */
470 (void) dsl_dir_create_sync(dp
, dp
->dp_root_dir
,
472 VERIFY0(dsl_pool_open_special_dir(dp
,
473 FREE_DIR_NAME
, &dp
->dp_free_dir
));
475 /* create and open the free_bplist */
476 obj
= bpobj_alloc(dp
->dp_meta_objset
, SPA_OLD_MAXBLOCKSIZE
, tx
);
477 VERIFY(zap_add(dp
->dp_meta_objset
, DMU_POOL_DIRECTORY_OBJECT
,
478 DMU_POOL_FREE_BPOBJ
, sizeof (uint64_t), 1, &obj
, tx
) == 0);
479 VERIFY0(bpobj_open(&dp
->dp_free_bpobj
,
480 dp
->dp_meta_objset
, obj
));
483 if (spa_version(spa
) >= SPA_VERSION_DSL_SCRUB
)
484 dsl_pool_create_origin(dp
, tx
);
486 /* create the root dataset */
487 obj
= dsl_dataset_create_sync_dd(dp
->dp_root_dir
, NULL
, 0, tx
);
489 /* create the root objset */
490 VERIFY0(dsl_dataset_hold_obj(dp
, obj
, FTAG
, &ds
));
494 rrw_enter(&ds
->ds_bp_rwlock
, RW_READER
, FTAG
);
495 os
= dmu_objset_create_impl(dp
->dp_spa
, ds
,
496 dsl_dataset_get_blkptr(ds
), DMU_OST_ZFS
, tx
);
497 rrw_exit(&ds
->ds_bp_rwlock
, FTAG
);
498 zfs_create_fs(os
, kcred
, zplprops
, tx
);
501 dsl_dataset_rele(ds
, FTAG
);
505 rrw_exit(&dp
->dp_config_rwlock
, FTAG
);
511 * Account for the meta-objset space in its placeholder dsl_dir.
514 dsl_pool_mos_diduse_space(dsl_pool_t
*dp
,
515 int64_t used
, int64_t comp
, int64_t uncomp
)
517 ASSERT3U(comp
, ==, uncomp
); /* it's all metadata */
518 mutex_enter(&dp
->dp_lock
);
519 dp
->dp_mos_used_delta
+= used
;
520 dp
->dp_mos_compressed_delta
+= comp
;
521 dp
->dp_mos_uncompressed_delta
+= uncomp
;
522 mutex_exit(&dp
->dp_lock
);
526 dsl_pool_sync_mos(dsl_pool_t
*dp
, dmu_tx_t
*tx
)
528 zio_t
*zio
= zio_root(dp
->dp_spa
, NULL
, NULL
, ZIO_FLAG_MUSTSUCCEED
);
529 dmu_objset_sync(dp
->dp_meta_objset
, zio
, tx
);
530 VERIFY0(zio_wait(zio
));
531 dprintf_bp(&dp
->dp_meta_rootbp
, "meta objset rootbp is %s", "");
532 spa_set_rootblkptr(dp
->dp_spa
, &dp
->dp_meta_rootbp
);
536 dsl_pool_dirty_delta(dsl_pool_t
*dp
, int64_t delta
)
538 ASSERT(MUTEX_HELD(&dp
->dp_lock
));
541 ASSERT3U(-delta
, <=, dp
->dp_dirty_total
);
543 dp
->dp_dirty_total
+= delta
;
546 * Note: we signal even when increasing dp_dirty_total.
547 * This ensures forward progress -- each thread wakes the next waiter.
549 if (dp
->dp_dirty_total
< zfs_dirty_data_max
)
550 cv_signal(&dp
->dp_spaceavail_cv
);
554 dsl_early_sync_task_verify(dsl_pool_t
*dp
, uint64_t txg
)
556 spa_t
*spa
= dp
->dp_spa
;
557 vdev_t
*rvd
= spa
->spa_root_vdev
;
559 for (uint64_t c
= 0; c
< rvd
->vdev_children
; c
++) {
560 vdev_t
*vd
= rvd
->vdev_child
[c
];
561 txg_list_t
*tl
= &vd
->vdev_ms_list
;
564 for (ms
= txg_list_head(tl
, TXG_CLEAN(txg
)); ms
;
565 ms
= txg_list_next(tl
, ms
, TXG_CLEAN(txg
))) {
566 VERIFY(range_tree_is_empty(ms
->ms_freeing
));
567 VERIFY(range_tree_is_empty(ms
->ms_checkpointing
));
575 dsl_pool_sync(dsl_pool_t
*dp
, uint64_t txg
)
581 objset_t
*mos
= dp
->dp_meta_objset
;
582 list_t synced_datasets
;
584 list_create(&synced_datasets
, sizeof (dsl_dataset_t
),
585 offsetof(dsl_dataset_t
, ds_synced_link
));
587 tx
= dmu_tx_create_assigned(dp
, txg
);
590 * Run all early sync tasks before writing out any dirty blocks.
591 * For more info on early sync tasks see block comment in
592 * dsl_early_sync_task().
594 if (!txg_list_empty(&dp
->dp_early_sync_tasks
, txg
)) {
595 dsl_sync_task_t
*dst
;
597 ASSERT3U(spa_sync_pass(dp
->dp_spa
), ==, 1);
599 txg_list_remove(&dp
->dp_early_sync_tasks
, txg
)) != NULL
) {
600 ASSERT(dsl_early_sync_task_verify(dp
, txg
));
601 dsl_sync_task_sync(dst
, tx
);
603 ASSERT(dsl_early_sync_task_verify(dp
, txg
));
607 * Write out all dirty blocks of dirty datasets.
609 zio
= zio_root(dp
->dp_spa
, NULL
, NULL
, ZIO_FLAG_MUSTSUCCEED
);
610 while ((ds
= txg_list_remove(&dp
->dp_dirty_datasets
, txg
)) != NULL
) {
612 * We must not sync any non-MOS datasets twice, because
613 * we may have taken a snapshot of them. However, we
614 * may sync newly-created datasets on pass 2.
616 ASSERT(!list_link_active(&ds
->ds_synced_link
));
617 list_insert_tail(&synced_datasets
, ds
);
618 dsl_dataset_sync(ds
, zio
, tx
);
620 VERIFY0(zio_wait(zio
));
623 * We have written all of the accounted dirty data, so our
624 * dp_space_towrite should now be zero. However, some seldom-used
625 * code paths do not adhere to this (e.g. dbuf_undirty(), also
626 * rounding error in dbuf_write_physdone).
627 * Shore up the accounting of any dirtied space now.
629 dsl_pool_undirty_space(dp
, dp
->dp_dirty_pertxg
[txg
& TXG_MASK
], txg
);
632 * Update the long range free counter after
633 * we're done syncing user data
635 mutex_enter(&dp
->dp_lock
);
636 ASSERT(spa_sync_pass(dp
->dp_spa
) == 1 ||
637 dp
->dp_long_free_dirty_pertxg
[txg
& TXG_MASK
] == 0);
638 dp
->dp_long_free_dirty_pertxg
[txg
& TXG_MASK
] = 0;
639 mutex_exit(&dp
->dp_lock
);
642 * After the data blocks have been written (ensured by the zio_wait()
643 * above), update the user/group space accounting. This happens
644 * in tasks dispatched to dp_sync_taskq, so wait for them before
647 for (ds
= list_head(&synced_datasets
); ds
!= NULL
;
648 ds
= list_next(&synced_datasets
, ds
)) {
649 dmu_objset_do_userquota_updates(ds
->ds_objset
, tx
);
651 taskq_wait(dp
->dp_sync_taskq
);
654 * Sync the datasets again to push out the changes due to
655 * userspace updates. This must be done before we process the
656 * sync tasks, so that any snapshots will have the correct
657 * user accounting information (and we won't get confused
658 * about which blocks are part of the snapshot).
660 zio
= zio_root(dp
->dp_spa
, NULL
, NULL
, ZIO_FLAG_MUSTSUCCEED
);
661 while ((ds
= txg_list_remove(&dp
->dp_dirty_datasets
, txg
)) != NULL
) {
662 ASSERT(list_link_active(&ds
->ds_synced_link
));
663 dmu_buf_rele(ds
->ds_dbuf
, ds
);
664 dsl_dataset_sync(ds
, zio
, tx
);
666 VERIFY0(zio_wait(zio
));
669 * Now that the datasets have been completely synced, we can
670 * clean up our in-memory structures accumulated while syncing:
672 * - move dead blocks from the pending deadlist to the on-disk deadlist
673 * - release hold from dsl_dataset_dirty()
675 while ((ds
= list_remove_head(&synced_datasets
)) != NULL
) {
676 dsl_dataset_sync_done(ds
, tx
);
678 while ((dd
= txg_list_remove(&dp
->dp_dirty_dirs
, txg
)) != NULL
) {
679 dsl_dir_sync(dd
, tx
);
683 * The MOS's space is accounted for in the pool/$MOS
684 * (dp_mos_dir). We can't modify the mos while we're syncing
685 * it, so we remember the deltas and apply them here.
687 if (dp
->dp_mos_used_delta
!= 0 || dp
->dp_mos_compressed_delta
!= 0 ||
688 dp
->dp_mos_uncompressed_delta
!= 0) {
689 dsl_dir_diduse_space(dp
->dp_mos_dir
, DD_USED_HEAD
,
690 dp
->dp_mos_used_delta
,
691 dp
->dp_mos_compressed_delta
,
692 dp
->dp_mos_uncompressed_delta
, tx
);
693 dp
->dp_mos_used_delta
= 0;
694 dp
->dp_mos_compressed_delta
= 0;
695 dp
->dp_mos_uncompressed_delta
= 0;
698 if (!multilist_is_empty(mos
->os_dirty_dnodes
[txg
& TXG_MASK
])) {
699 dsl_pool_sync_mos(dp
, tx
);
703 * If we modify a dataset in the same txg that we want to destroy it,
704 * its dsl_dir's dd_dbuf will be dirty, and thus have a hold on it.
705 * dsl_dir_destroy_check() will fail if there are unexpected holds.
706 * Therefore, we want to sync the MOS (thus syncing the dd_dbuf
707 * and clearing the hold on it) before we process the sync_tasks.
708 * The MOS data dirtied by the sync_tasks will be synced on the next
711 if (!txg_list_empty(&dp
->dp_sync_tasks
, txg
)) {
712 dsl_sync_task_t
*dst
;
714 * No more sync tasks should have been added while we
717 ASSERT3U(spa_sync_pass(dp
->dp_spa
), ==, 1);
718 while ((dst
= txg_list_remove(&dp
->dp_sync_tasks
, txg
)) != NULL
)
719 dsl_sync_task_sync(dst
, tx
);
724 DTRACE_PROBE2(dsl_pool_sync__done
, dsl_pool_t
*dp
, dp
, uint64_t, txg
);
728 dsl_pool_sync_done(dsl_pool_t
*dp
, uint64_t txg
)
732 while (zilog
= txg_list_head(&dp
->dp_dirty_zilogs
, txg
)) {
733 dsl_dataset_t
*ds
= dmu_objset_ds(zilog
->zl_os
);
735 * We don't remove the zilog from the dp_dirty_zilogs
736 * list until after we've cleaned it. This ensures that
737 * callers of zilog_is_dirty() receive an accurate
738 * answer when they are racing with the spa sync thread.
740 zil_clean(zilog
, txg
);
741 (void) txg_list_remove_this(&dp
->dp_dirty_zilogs
, zilog
, txg
);
742 ASSERT(!dmu_objset_is_dirty(zilog
->zl_os
, txg
));
743 dmu_buf_rele(ds
->ds_dbuf
, zilog
);
745 ASSERT(!dmu_objset_is_dirty(dp
->dp_meta_objset
, txg
));
749 * TRUE if the current thread is the tx_sync_thread or if we
750 * are being called from SPA context during pool initialization.
753 dsl_pool_sync_context(dsl_pool_t
*dp
)
755 return (curthread
== dp
->dp_tx
.tx_sync_thread
||
756 spa_is_initializing(dp
->dp_spa
) ||
757 taskq_member(dp
->dp_sync_taskq
, curthread
));
761 * This function returns the amount of allocatable space in the pool
762 * minus whatever space is currently reserved by ZFS for specific
763 * purposes. Specifically:
765 * 1] Any reserved SLOP space
766 * 2] Any space used by the checkpoint
767 * 3] Any space used for deferred frees
769 * The latter 2 are especially important because they are needed to
770 * rectify the SPA's and DMU's different understanding of how much space
771 * is used. Now the DMU is aware of that extra space tracked by the SPA
772 * without having to maintain a separate special dir (e.g similar to
773 * $MOS, $FREEING, and $LEAKED).
775 * Note: By deferred frees here, we mean the frees that were deferred
776 * in spa_sync() after sync pass 1 (spa_deferred_bpobj), and not the
777 * segments placed in ms_defer trees during metaslab_sync_done().
780 dsl_pool_adjustedsize(dsl_pool_t
*dp
, zfs_space_check_t slop_policy
)
782 spa_t
*spa
= dp
->dp_spa
;
783 uint64_t space
, resv
, adjustedsize
;
784 uint64_t spa_deferred_frees
=
785 spa
->spa_deferred_bpobj
.bpo_phys
->bpo_bytes
;
787 space
= spa_get_dspace(spa
)
788 - spa_get_checkpoint_space(spa
) - spa_deferred_frees
;
789 resv
= spa_get_slop_space(spa
);
791 switch (slop_policy
) {
792 case ZFS_SPACE_CHECK_NORMAL
:
794 case ZFS_SPACE_CHECK_RESERVED
:
797 case ZFS_SPACE_CHECK_EXTRA_RESERVED
:
800 case ZFS_SPACE_CHECK_NONE
:
804 panic("invalid slop policy value: %d", slop_policy
);
807 adjustedsize
= (space
>= resv
) ? (space
- resv
) : 0;
809 return (adjustedsize
);
813 dsl_pool_unreserved_space(dsl_pool_t
*dp
, zfs_space_check_t slop_policy
)
815 uint64_t poolsize
= dsl_pool_adjustedsize(dp
, slop_policy
);
817 metaslab_class_get_deferred(spa_normal_class(dp
->dp_spa
));
818 uint64_t quota
= (poolsize
>= deferred
) ? (poolsize
- deferred
) : 0;
823 dsl_pool_need_dirty_delay(dsl_pool_t
*dp
)
825 uint64_t delay_min_bytes
=
826 zfs_dirty_data_max
* zfs_delay_min_dirty_percent
/ 100;
829 mutex_enter(&dp
->dp_lock
);
830 if (dp
->dp_dirty_total
> zfs_dirty_data_sync
)
832 rv
= (dp
->dp_dirty_total
> delay_min_bytes
);
833 mutex_exit(&dp
->dp_lock
);
838 dsl_pool_dirty_space(dsl_pool_t
*dp
, int64_t space
, dmu_tx_t
*tx
)
841 mutex_enter(&dp
->dp_lock
);
842 dp
->dp_dirty_pertxg
[tx
->tx_txg
& TXG_MASK
] += space
;
843 dsl_pool_dirty_delta(dp
, space
);
844 mutex_exit(&dp
->dp_lock
);
849 dsl_pool_undirty_space(dsl_pool_t
*dp
, int64_t space
, uint64_t txg
)
851 ASSERT3S(space
, >=, 0);
854 mutex_enter(&dp
->dp_lock
);
855 if (dp
->dp_dirty_pertxg
[txg
& TXG_MASK
] < space
) {
856 /* XXX writing something we didn't dirty? */
857 space
= dp
->dp_dirty_pertxg
[txg
& TXG_MASK
];
859 ASSERT3U(dp
->dp_dirty_pertxg
[txg
& TXG_MASK
], >=, space
);
860 dp
->dp_dirty_pertxg
[txg
& TXG_MASK
] -= space
;
861 ASSERT3U(dp
->dp_dirty_total
, >=, space
);
862 dsl_pool_dirty_delta(dp
, -space
);
863 mutex_exit(&dp
->dp_lock
);
868 upgrade_clones_cb(dsl_pool_t
*dp
, dsl_dataset_t
*hds
, void *arg
)
871 dsl_dataset_t
*ds
, *prev
= NULL
;
874 err
= dsl_dataset_hold_obj(dp
, hds
->ds_object
, FTAG
, &ds
);
878 while (dsl_dataset_phys(ds
)->ds_prev_snap_obj
!= 0) {
879 err
= dsl_dataset_hold_obj(dp
,
880 dsl_dataset_phys(ds
)->ds_prev_snap_obj
, FTAG
, &prev
);
882 dsl_dataset_rele(ds
, FTAG
);
886 if (dsl_dataset_phys(prev
)->ds_next_snap_obj
!= ds
->ds_object
)
888 dsl_dataset_rele(ds
, FTAG
);
894 prev
= dp
->dp_origin_snap
;
897 * The $ORIGIN can't have any data, or the accounting
900 rrw_enter(&ds
->ds_bp_rwlock
, RW_READER
, FTAG
);
901 ASSERT0(dsl_dataset_phys(prev
)->ds_bp
.blk_birth
);
902 rrw_exit(&ds
->ds_bp_rwlock
, FTAG
);
904 /* The origin doesn't get attached to itself */
905 if (ds
->ds_object
== prev
->ds_object
) {
906 dsl_dataset_rele(ds
, FTAG
);
910 dmu_buf_will_dirty(ds
->ds_dbuf
, tx
);
911 dsl_dataset_phys(ds
)->ds_prev_snap_obj
= prev
->ds_object
;
912 dsl_dataset_phys(ds
)->ds_prev_snap_txg
=
913 dsl_dataset_phys(prev
)->ds_creation_txg
;
915 dmu_buf_will_dirty(ds
->ds_dir
->dd_dbuf
, tx
);
916 dsl_dir_phys(ds
->ds_dir
)->dd_origin_obj
= prev
->ds_object
;
918 dmu_buf_will_dirty(prev
->ds_dbuf
, tx
);
919 dsl_dataset_phys(prev
)->ds_num_children
++;
921 if (dsl_dataset_phys(ds
)->ds_next_snap_obj
== 0) {
922 ASSERT(ds
->ds_prev
== NULL
);
923 VERIFY0(dsl_dataset_hold_obj(dp
,
924 dsl_dataset_phys(ds
)->ds_prev_snap_obj
,
929 ASSERT3U(dsl_dir_phys(ds
->ds_dir
)->dd_origin_obj
, ==, prev
->ds_object
);
930 ASSERT3U(dsl_dataset_phys(ds
)->ds_prev_snap_obj
, ==, prev
->ds_object
);
932 if (dsl_dataset_phys(prev
)->ds_next_clones_obj
== 0) {
933 dmu_buf_will_dirty(prev
->ds_dbuf
, tx
);
934 dsl_dataset_phys(prev
)->ds_next_clones_obj
=
935 zap_create(dp
->dp_meta_objset
,
936 DMU_OT_NEXT_CLONES
, DMU_OT_NONE
, 0, tx
);
938 VERIFY0(zap_add_int(dp
->dp_meta_objset
,
939 dsl_dataset_phys(prev
)->ds_next_clones_obj
, ds
->ds_object
, tx
));
941 dsl_dataset_rele(ds
, FTAG
);
942 if (prev
!= dp
->dp_origin_snap
)
943 dsl_dataset_rele(prev
, FTAG
);
948 dsl_pool_upgrade_clones(dsl_pool_t
*dp
, dmu_tx_t
*tx
)
950 ASSERT(dmu_tx_is_syncing(tx
));
951 ASSERT(dp
->dp_origin_snap
!= NULL
);
953 VERIFY0(dmu_objset_find_dp(dp
, dp
->dp_root_dir_obj
, upgrade_clones_cb
,
954 tx
, DS_FIND_CHILDREN
| DS_FIND_SERIALIZE
));
959 upgrade_dir_clones_cb(dsl_pool_t
*dp
, dsl_dataset_t
*ds
, void *arg
)
962 objset_t
*mos
= dp
->dp_meta_objset
;
964 if (dsl_dir_phys(ds
->ds_dir
)->dd_origin_obj
!= 0) {
965 dsl_dataset_t
*origin
;
967 VERIFY0(dsl_dataset_hold_obj(dp
,
968 dsl_dir_phys(ds
->ds_dir
)->dd_origin_obj
, FTAG
, &origin
));
970 if (dsl_dir_phys(origin
->ds_dir
)->dd_clones
== 0) {
971 dmu_buf_will_dirty(origin
->ds_dir
->dd_dbuf
, tx
);
972 dsl_dir_phys(origin
->ds_dir
)->dd_clones
=
973 zap_create(mos
, DMU_OT_DSL_CLONES
, DMU_OT_NONE
,
977 VERIFY0(zap_add_int(dp
->dp_meta_objset
,
978 dsl_dir_phys(origin
->ds_dir
)->dd_clones
,
981 dsl_dataset_rele(origin
, FTAG
);
987 dsl_pool_upgrade_dir_clones(dsl_pool_t
*dp
, dmu_tx_t
*tx
)
989 ASSERT(dmu_tx_is_syncing(tx
));
992 (void) dsl_dir_create_sync(dp
, dp
->dp_root_dir
, FREE_DIR_NAME
, tx
);
993 VERIFY0(dsl_pool_open_special_dir(dp
,
994 FREE_DIR_NAME
, &dp
->dp_free_dir
));
997 * We can't use bpobj_alloc(), because spa_version() still
998 * returns the old version, and we need a new-version bpobj with
999 * subobj support. So call dmu_object_alloc() directly.
1001 obj
= dmu_object_alloc(dp
->dp_meta_objset
, DMU_OT_BPOBJ
,
1002 SPA_OLD_MAXBLOCKSIZE
, DMU_OT_BPOBJ_HDR
, sizeof (bpobj_phys_t
), tx
);
1003 VERIFY0(zap_add(dp
->dp_meta_objset
, DMU_POOL_DIRECTORY_OBJECT
,
1004 DMU_POOL_FREE_BPOBJ
, sizeof (uint64_t), 1, &obj
, tx
));
1005 VERIFY0(bpobj_open(&dp
->dp_free_bpobj
, dp
->dp_meta_objset
, obj
));
1007 VERIFY0(dmu_objset_find_dp(dp
, dp
->dp_root_dir_obj
,
1008 upgrade_dir_clones_cb
, tx
, DS_FIND_CHILDREN
| DS_FIND_SERIALIZE
));
1012 dsl_pool_create_origin(dsl_pool_t
*dp
, dmu_tx_t
*tx
)
1017 ASSERT(dmu_tx_is_syncing(tx
));
1018 ASSERT(dp
->dp_origin_snap
== NULL
);
1019 ASSERT(rrw_held(&dp
->dp_config_rwlock
, RW_WRITER
));
1021 /* create the origin dir, ds, & snap-ds */
1022 dsobj
= dsl_dataset_create_sync(dp
->dp_root_dir
, ORIGIN_DIR_NAME
,
1023 NULL
, 0, kcred
, tx
);
1024 VERIFY0(dsl_dataset_hold_obj(dp
, dsobj
, FTAG
, &ds
));
1025 dsl_dataset_snapshot_sync_impl(ds
, ORIGIN_DIR_NAME
, tx
);
1026 VERIFY0(dsl_dataset_hold_obj(dp
, dsl_dataset_phys(ds
)->ds_prev_snap_obj
,
1027 dp
, &dp
->dp_origin_snap
));
1028 dsl_dataset_rele(ds
, FTAG
);
1032 dsl_pool_vnrele_taskq(dsl_pool_t
*dp
)
1034 return (dp
->dp_vnrele_taskq
);
1038 * Walk through the pool-wide zap object of temporary snapshot user holds
1042 dsl_pool_clean_tmp_userrefs(dsl_pool_t
*dp
)
1046 objset_t
*mos
= dp
->dp_meta_objset
;
1047 uint64_t zapobj
= dp
->dp_tmp_userrefs_obj
;
1052 ASSERT(spa_version(dp
->dp_spa
) >= SPA_VERSION_USERREFS
);
1054 holds
= fnvlist_alloc();
1056 for (zap_cursor_init(&zc
, mos
, zapobj
);
1057 zap_cursor_retrieve(&zc
, &za
) == 0;
1058 zap_cursor_advance(&zc
)) {
1062 htag
= strchr(za
.za_name
, '-');
1065 if (nvlist_lookup_nvlist(holds
, za
.za_name
, &tags
) != 0) {
1066 tags
= fnvlist_alloc();
1067 fnvlist_add_boolean(tags
, htag
);
1068 fnvlist_add_nvlist(holds
, za
.za_name
, tags
);
1071 fnvlist_add_boolean(tags
, htag
);
1074 dsl_dataset_user_release_tmp(dp
, holds
);
1075 fnvlist_free(holds
);
1076 zap_cursor_fini(&zc
);
1080 * Create the pool-wide zap object for storing temporary snapshot holds.
1083 dsl_pool_user_hold_create_obj(dsl_pool_t
*dp
, dmu_tx_t
*tx
)
1085 objset_t
*mos
= dp
->dp_meta_objset
;
1087 ASSERT(dp
->dp_tmp_userrefs_obj
== 0);
1088 ASSERT(dmu_tx_is_syncing(tx
));
1090 dp
->dp_tmp_userrefs_obj
= zap_create_link(mos
, DMU_OT_USERREFS
,
1091 DMU_POOL_DIRECTORY_OBJECT
, DMU_POOL_TMP_USERREFS
, tx
);
1095 dsl_pool_user_hold_rele_impl(dsl_pool_t
*dp
, uint64_t dsobj
,
1096 const char *tag
, uint64_t now
, dmu_tx_t
*tx
, boolean_t holding
)
1098 objset_t
*mos
= dp
->dp_meta_objset
;
1099 uint64_t zapobj
= dp
->dp_tmp_userrefs_obj
;
1103 ASSERT(spa_version(dp
->dp_spa
) >= SPA_VERSION_USERREFS
);
1104 ASSERT(dmu_tx_is_syncing(tx
));
1107 * If the pool was created prior to SPA_VERSION_USERREFS, the
1108 * zap object for temporary holds might not exist yet.
1112 dsl_pool_user_hold_create_obj(dp
, tx
);
1113 zapobj
= dp
->dp_tmp_userrefs_obj
;
1115 return (SET_ERROR(ENOENT
));
1119 name
= kmem_asprintf("%llx-%s", (u_longlong_t
)dsobj
, tag
);
1121 error
= zap_add(mos
, zapobj
, name
, 8, 1, &now
, tx
);
1123 error
= zap_remove(mos
, zapobj
, name
, tx
);
1130 * Add a temporary hold for the given dataset object and tag.
1133 dsl_pool_user_hold(dsl_pool_t
*dp
, uint64_t dsobj
, const char *tag
,
1134 uint64_t now
, dmu_tx_t
*tx
)
1136 return (dsl_pool_user_hold_rele_impl(dp
, dsobj
, tag
, now
, tx
, B_TRUE
));
1140 * Release a temporary hold for the given dataset object and tag.
1143 dsl_pool_user_release(dsl_pool_t
*dp
, uint64_t dsobj
, const char *tag
,
1146 return (dsl_pool_user_hold_rele_impl(dp
, dsobj
, tag
, (uintptr_t)NULL
,
1151 * DSL Pool Configuration Lock
1153 * The dp_config_rwlock protects against changes to DSL state (e.g. dataset
1154 * creation / destruction / rename / property setting). It must be held for
1155 * read to hold a dataset or dsl_dir. I.e. you must call
1156 * dsl_pool_config_enter() or dsl_pool_hold() before calling
1157 * dsl_{dataset,dir}_hold{_obj}. In most circumstances, the dp_config_rwlock
1158 * must be held continuously until all datasets and dsl_dirs are released.
1160 * The only exception to this rule is that if a "long hold" is placed on
1161 * a dataset, then the dp_config_rwlock may be dropped while the dataset
1162 * is still held. The long hold will prevent the dataset from being
1163 * destroyed -- the destroy will fail with EBUSY. A long hold can be
1164 * obtained by calling dsl_dataset_long_hold(), or by "owning" a dataset
1165 * (by calling dsl_{dataset,objset}_{try}own{_obj}).
1167 * Legitimate long-holders (including owners) should be long-running, cancelable
1168 * tasks that should cause "zfs destroy" to fail. This includes DMU
1169 * consumers (i.e. a ZPL filesystem being mounted or ZVOL being open),
1170 * "zfs send", and "zfs diff". There are several other long-holders whose
1171 * uses are suboptimal (e.g. "zfs promote", and zil_suspend()).
1173 * The usual formula for long-holding would be:
1175 * dsl_dataset_hold()
1176 * ... perform checks ...
1177 * dsl_dataset_long_hold()
1179 * ... perform long-running task ...
1180 * dsl_dataset_long_rele()
1181 * dsl_dataset_rele()
1183 * Note that when the long hold is released, the dataset is still held but
1184 * the pool is not held. The dataset may change arbitrarily during this time
1185 * (e.g. it could be destroyed). Therefore you shouldn't do anything to the
1186 * dataset except release it.
1188 * User-initiated operations (e.g. ioctls, zfs_ioc_*()) are either read-only
1189 * or modifying operations.
1191 * Modifying operations should generally use dsl_sync_task(). The synctask
1192 * infrastructure enforces proper locking strategy with respect to the
1193 * dp_config_rwlock. See the comment above dsl_sync_task() for details.
1195 * Read-only operations will manually hold the pool, then the dataset, obtain
1196 * information from the dataset, then release the pool and dataset.
1197 * dmu_objset_{hold,rele}() are convenience routines that also do the pool
1202 dsl_pool_hold(const char *name
, void *tag
, dsl_pool_t
**dp
)
1207 error
= spa_open(name
, &spa
, tag
);
1209 *dp
= spa_get_dsl(spa
);
1210 dsl_pool_config_enter(*dp
, tag
);
1216 dsl_pool_rele(dsl_pool_t
*dp
, void *tag
)
1218 dsl_pool_config_exit(dp
, tag
);
1219 spa_close(dp
->dp_spa
, tag
);
1223 dsl_pool_config_enter(dsl_pool_t
*dp
, void *tag
)
1226 * We use a "reentrant" reader-writer lock, but not reentrantly.
1228 * The rrwlock can (with the track_all flag) track all reading threads,
1229 * which is very useful for debugging which code path failed to release
1230 * the lock, and for verifying that the *current* thread does hold
1233 * (Unlike a rwlock, which knows that N threads hold it for
1234 * read, but not *which* threads, so rw_held(RW_READER) returns TRUE
1235 * if any thread holds it for read, even if this thread doesn't).
1237 ASSERT(!rrw_held(&dp
->dp_config_rwlock
, RW_READER
));
1238 rrw_enter(&dp
->dp_config_rwlock
, RW_READER
, tag
);
1242 dsl_pool_config_enter_prio(dsl_pool_t
*dp
, void *tag
)
1244 ASSERT(!rrw_held(&dp
->dp_config_rwlock
, RW_READER
));
1245 rrw_enter_read_prio(&dp
->dp_config_rwlock
, tag
);
1249 dsl_pool_config_exit(dsl_pool_t
*dp
, void *tag
)
1251 rrw_exit(&dp
->dp_config_rwlock
, tag
);
1255 dsl_pool_config_held(dsl_pool_t
*dp
)
1257 return (RRW_LOCK_HELD(&dp
->dp_config_rwlock
));
1261 dsl_pool_config_held_writer(dsl_pool_t
*dp
)
1263 return (RRW_WRITE_HELD(&dp
->dp_config_rwlock
));