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 2011 Nexenta Systems, Inc. All rights reserved.
24 * Copyright (c) 2012, 2019 by Delphix. All rights reserved.
25 * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
26 * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
29 #include <sys/zfs_context.h>
32 #include <sys/dmu_send.h>
33 #include <sys/dmu_impl.h>
35 #include <sys/dmu_objset.h>
36 #include <sys/dsl_dataset.h>
37 #include <sys/dsl_dir.h>
38 #include <sys/dmu_tx.h>
41 #include <sys/dmu_zfetch.h>
43 #include <sys/sa_impl.h>
44 #include <sys/zfeature.h>
45 #include <sys/blkptr.h>
46 #include <sys/range_tree.h>
47 #include <sys/trace_zfs.h>
48 #include <sys/callb.h>
51 #include <sys/cityhash.h>
52 #include <sys/spa_impl.h>
56 typedef struct dbuf_stats {
58 * Various statistics about the size of the dbuf cache.
60 kstat_named_t cache_count;
61 kstat_named_t cache_size_bytes;
62 kstat_named_t cache_size_bytes_max;
64 * Statistics regarding the bounds on the dbuf cache size.
66 kstat_named_t cache_target_bytes;
67 kstat_named_t cache_lowater_bytes;
68 kstat_named_t cache_hiwater_bytes;
70 * Total number of dbuf cache evictions that have occurred.
72 kstat_named_t cache_total_evicts;
74 * The distribution of dbuf levels in the dbuf cache and
75 * the total size of all dbufs at each level.
77 kstat_named_t cache_levels[DN_MAX_LEVELS];
78 kstat_named_t cache_levels_bytes[DN_MAX_LEVELS];
80 * Statistics about the dbuf hash table.
82 kstat_named_t hash_hits;
83 kstat_named_t hash_misses;
84 kstat_named_t hash_collisions;
85 kstat_named_t hash_elements;
86 kstat_named_t hash_elements_max;
88 * Number of sublists containing more than one dbuf in the dbuf
89 * hash table. Keep track of the longest hash chain.
91 kstat_named_t hash_chains;
92 kstat_named_t hash_chain_max;
94 * Number of times a dbuf_create() discovers that a dbuf was
95 * already created and in the dbuf hash table.
97 kstat_named_t hash_insert_race;
99 * Statistics about the size of the metadata dbuf cache.
101 kstat_named_t metadata_cache_count;
102 kstat_named_t metadata_cache_size_bytes;
103 kstat_named_t metadata_cache_size_bytes_max;
105 * For diagnostic purposes, this is incremented whenever we can't add
106 * something to the metadata cache because it's full, and instead put
107 * the data in the regular dbuf cache.
109 kstat_named_t metadata_cache_overflow;
112 dbuf_stats_t dbuf_stats = {
113 { "cache_count", KSTAT_DATA_UINT64 },
114 { "cache_size_bytes", KSTAT_DATA_UINT64 },
115 { "cache_size_bytes_max", KSTAT_DATA_UINT64 },
116 { "cache_target_bytes", KSTAT_DATA_UINT64 },
117 { "cache_lowater_bytes", KSTAT_DATA_UINT64 },
118 { "cache_hiwater_bytes", KSTAT_DATA_UINT64 },
119 { "cache_total_evicts", KSTAT_DATA_UINT64 },
120 { { "cache_levels_N", KSTAT_DATA_UINT64 } },
121 { { "cache_levels_bytes_N", KSTAT_DATA_UINT64 } },
122 { "hash_hits", KSTAT_DATA_UINT64 },
123 { "hash_misses", KSTAT_DATA_UINT64 },
124 { "hash_collisions", KSTAT_DATA_UINT64 },
125 { "hash_elements", KSTAT_DATA_UINT64 },
126 { "hash_elements_max", KSTAT_DATA_UINT64 },
127 { "hash_chains", KSTAT_DATA_UINT64 },
128 { "hash_chain_max", KSTAT_DATA_UINT64 },
129 { "hash_insert_race", KSTAT_DATA_UINT64 },
130 { "metadata_cache_count", KSTAT_DATA_UINT64 },
131 { "metadata_cache_size_bytes", KSTAT_DATA_UINT64 },
132 { "metadata_cache_size_bytes_max", KSTAT_DATA_UINT64 },
133 { "metadata_cache_overflow", KSTAT_DATA_UINT64 }
136 #define DBUF_STAT_INCR(stat, val) \
137 atomic_add_64(&dbuf_stats.stat.value.ui64, (val));
138 #define DBUF_STAT_DECR(stat, val) \
139 DBUF_STAT_INCR(stat, -(val));
140 #define DBUF_STAT_BUMP(stat) \
141 DBUF_STAT_INCR(stat, 1);
142 #define DBUF_STAT_BUMPDOWN(stat) \
143 DBUF_STAT_INCR(stat, -1);
144 #define DBUF_STAT_MAX(stat, v) { \
146 while ((v) > (_m = dbuf_stats.stat.value.ui64) && \
147 (_m != atomic_cas_64(&dbuf_stats.stat.value.ui64, _m, (v))))\
151 static boolean_t dbuf_undirty(dmu_buf_impl_t *db, dmu_tx_t *tx);
152 static void dbuf_write(dbuf_dirty_record_t *dr, arc_buf_t *data, dmu_tx_t *tx);
154 extern inline void dmu_buf_init_user(dmu_buf_user_t *dbu,
155 dmu_buf_evict_func_t *evict_func_sync,
156 dmu_buf_evict_func_t *evict_func_async,
157 dmu_buf_t **clear_on_evict_dbufp);
160 * Global data structures and functions for the dbuf cache.
162 static kmem_cache_t *dbuf_kmem_cache;
163 static taskq_t *dbu_evict_taskq;
165 static kthread_t *dbuf_cache_evict_thread;
166 static kmutex_t dbuf_evict_lock;
167 static kcondvar_t dbuf_evict_cv;
168 static boolean_t dbuf_evict_thread_exit;
171 * There are two dbuf caches; each dbuf can only be in one of them at a time.
173 * 1. Cache of metadata dbufs, to help make read-heavy administrative commands
174 * from /sbin/zfs run faster. The "metadata cache" specifically stores dbufs
175 * that represent the metadata that describes filesystems/snapshots/
176 * bookmarks/properties/etc. We only evict from this cache when we export a
177 * pool, to short-circuit as much I/O as possible for all administrative
178 * commands that need the metadata. There is no eviction policy for this
179 * cache, because we try to only include types in it which would occupy a
180 * very small amount of space per object but create a large impact on the
181 * performance of these commands. Instead, after it reaches a maximum size
182 * (which should only happen on very small memory systems with a very large
183 * number of filesystem objects), we stop taking new dbufs into the
184 * metadata cache, instead putting them in the normal dbuf cache.
186 * 2. LRU cache of dbufs. The dbuf cache maintains a list of dbufs that
187 * are not currently held but have been recently released. These dbufs
188 * are not eligible for arc eviction until they are aged out of the cache.
189 * Dbufs that are aged out of the cache will be immediately destroyed and
190 * become eligible for arc eviction.
192 * Dbufs are added to these caches once the last hold is released. If a dbuf is
193 * later accessed and still exists in the dbuf cache, then it will be removed
194 * from the cache and later re-added to the head of the cache.
196 * If a given dbuf meets the requirements for the metadata cache, it will go
197 * there, otherwise it will be considered for the generic LRU dbuf cache. The
198 * caches and the refcounts tracking their sizes are stored in an array indexed
199 * by those caches' matching enum values (from dbuf_cached_state_t).
201 typedef struct dbuf_cache {
205 dbuf_cache_t dbuf_caches[DB_CACHE_MAX];
207 /* Size limits for the caches */
208 unsigned long dbuf_cache_max_bytes = 0;
209 unsigned long dbuf_metadata_cache_max_bytes = 0;
210 /* Set the default sizes of the caches to log2 fraction of arc size */
211 int dbuf_cache_shift = 5;
212 int dbuf_metadata_cache_shift = 6;
215 * The LRU dbuf cache uses a three-stage eviction policy:
216 * - A low water marker designates when the dbuf eviction thread
217 * should stop evicting from the dbuf cache.
218 * - When we reach the maximum size (aka mid water mark), we
219 * signal the eviction thread to run.
220 * - The high water mark indicates when the eviction thread
221 * is unable to keep up with the incoming load and eviction must
222 * happen in the context of the calling thread.
226 * low water mid water hi water
227 * +----------------------------------------+----------+----------+
232 * +----------------------------------------+----------+----------+
234 * evicting eviction directly
237 * The high and low water marks indicate the operating range for the eviction
238 * thread. The low water mark is, by default, 90% of the total size of the
239 * cache and the high water mark is at 110% (both of these percentages can be
240 * changed by setting dbuf_cache_lowater_pct and dbuf_cache_hiwater_pct,
241 * respectively). The eviction thread will try to ensure that the cache remains
242 * within this range by waking up every second and checking if the cache is
243 * above the low water mark. The thread can also be woken up by callers adding
244 * elements into the cache if the cache is larger than the mid water (i.e max
245 * cache size). Once the eviction thread is woken up and eviction is required,
246 * it will continue evicting buffers until it's able to reduce the cache size
247 * to the low water mark. If the cache size continues to grow and hits the high
248 * water mark, then callers adding elements to the cache will begin to evict
249 * directly from the cache until the cache is no longer above the high water
254 * The percentage above and below the maximum cache size.
256 uint_t dbuf_cache_hiwater_pct = 10;
257 uint_t dbuf_cache_lowater_pct = 10;
261 dbuf_cons(void *vdb, void *unused, int kmflag)
263 dmu_buf_impl_t *db = vdb;
264 bzero(db, sizeof (dmu_buf_impl_t));
266 mutex_init(&db->db_mtx, NULL, MUTEX_DEFAULT, NULL);
267 rw_init(&db->db_rwlock, NULL, RW_DEFAULT, NULL);
268 cv_init(&db->db_changed, NULL, CV_DEFAULT, NULL);
269 multilist_link_init(&db->db_cache_link);
270 zfs_refcount_create(&db->db_holds);
277 dbuf_dest(void *vdb, void *unused)
279 dmu_buf_impl_t *db = vdb;
280 mutex_destroy(&db->db_mtx);
281 rw_destroy(&db->db_rwlock);
282 cv_destroy(&db->db_changed);
283 ASSERT(!multilist_link_active(&db->db_cache_link));
284 zfs_refcount_destroy(&db->db_holds);
288 * dbuf hash table routines
290 static dbuf_hash_table_t dbuf_hash_table;
292 static uint64_t dbuf_hash_count;
295 * We use Cityhash for this. It's fast, and has good hash properties without
296 * requiring any large static buffers.
299 dbuf_hash(void *os, uint64_t obj, uint8_t lvl, uint64_t blkid)
301 return (cityhash4((uintptr_t)os, obj, (uint64_t)lvl, blkid));
304 #define DBUF_EQUAL(dbuf, os, obj, level, blkid) \
305 ((dbuf)->db.db_object == (obj) && \
306 (dbuf)->db_objset == (os) && \
307 (dbuf)->db_level == (level) && \
308 (dbuf)->db_blkid == (blkid))
311 dbuf_find(objset_t *os, uint64_t obj, uint8_t level, uint64_t blkid)
313 dbuf_hash_table_t *h = &dbuf_hash_table;
318 hv = dbuf_hash(os, obj, level, blkid);
319 idx = hv & h->hash_table_mask;
321 mutex_enter(DBUF_HASH_MUTEX(h, idx));
322 for (db = h->hash_table[idx]; db != NULL; db = db->db_hash_next) {
323 if (DBUF_EQUAL(db, os, obj, level, blkid)) {
324 mutex_enter(&db->db_mtx);
325 if (db->db_state != DB_EVICTING) {
326 mutex_exit(DBUF_HASH_MUTEX(h, idx));
329 mutex_exit(&db->db_mtx);
332 mutex_exit(DBUF_HASH_MUTEX(h, idx));
336 static dmu_buf_impl_t *
337 dbuf_find_bonus(objset_t *os, uint64_t object)
340 dmu_buf_impl_t *db = NULL;
342 if (dnode_hold(os, object, FTAG, &dn) == 0) {
343 rw_enter(&dn->dn_struct_rwlock, RW_READER);
344 if (dn->dn_bonus != NULL) {
346 mutex_enter(&db->db_mtx);
348 rw_exit(&dn->dn_struct_rwlock);
349 dnode_rele(dn, FTAG);
355 * Insert an entry into the hash table. If there is already an element
356 * equal to elem in the hash table, then the already existing element
357 * will be returned and the new element will not be inserted.
358 * Otherwise returns NULL.
360 static dmu_buf_impl_t *
361 dbuf_hash_insert(dmu_buf_impl_t *db)
363 dbuf_hash_table_t *h = &dbuf_hash_table;
364 objset_t *os = db->db_objset;
365 uint64_t obj = db->db.db_object;
366 int level = db->db_level;
367 uint64_t blkid, hv, idx;
371 blkid = db->db_blkid;
372 hv = dbuf_hash(os, obj, level, blkid);
373 idx = hv & h->hash_table_mask;
375 mutex_enter(DBUF_HASH_MUTEX(h, idx));
376 for (dbf = h->hash_table[idx], i = 0; dbf != NULL;
377 dbf = dbf->db_hash_next, i++) {
378 if (DBUF_EQUAL(dbf, os, obj, level, blkid)) {
379 mutex_enter(&dbf->db_mtx);
380 if (dbf->db_state != DB_EVICTING) {
381 mutex_exit(DBUF_HASH_MUTEX(h, idx));
384 mutex_exit(&dbf->db_mtx);
389 DBUF_STAT_BUMP(hash_collisions);
391 DBUF_STAT_BUMP(hash_chains);
393 DBUF_STAT_MAX(hash_chain_max, i);
396 mutex_enter(&db->db_mtx);
397 db->db_hash_next = h->hash_table[idx];
398 h->hash_table[idx] = db;
399 mutex_exit(DBUF_HASH_MUTEX(h, idx));
400 atomic_inc_64(&dbuf_hash_count);
401 DBUF_STAT_MAX(hash_elements_max, dbuf_hash_count);
407 * This returns whether this dbuf should be stored in the metadata cache, which
408 * is based on whether it's from one of the dnode types that store data related
409 * to traversing dataset hierarchies.
412 dbuf_include_in_metadata_cache(dmu_buf_impl_t *db)
415 dmu_object_type_t type = DB_DNODE(db)->dn_type;
418 /* Check if this dbuf is one of the types we care about */
419 if (DMU_OT_IS_METADATA_CACHED(type)) {
420 /* If we hit this, then we set something up wrong in dmu_ot */
421 ASSERT(DMU_OT_IS_METADATA(type));
424 * Sanity check for small-memory systems: don't allocate too
425 * much memory for this purpose.
427 if (zfs_refcount_count(
428 &dbuf_caches[DB_DBUF_METADATA_CACHE].size) >
429 dbuf_metadata_cache_max_bytes) {
430 DBUF_STAT_BUMP(metadata_cache_overflow);
441 * Remove an entry from the hash table. It must be in the EVICTING state.
444 dbuf_hash_remove(dmu_buf_impl_t *db)
446 dbuf_hash_table_t *h = &dbuf_hash_table;
448 dmu_buf_impl_t *dbf, **dbp;
450 hv = dbuf_hash(db->db_objset, db->db.db_object,
451 db->db_level, db->db_blkid);
452 idx = hv & h->hash_table_mask;
455 * We mustn't hold db_mtx to maintain lock ordering:
456 * DBUF_HASH_MUTEX > db_mtx.
458 ASSERT(zfs_refcount_is_zero(&db->db_holds));
459 ASSERT(db->db_state == DB_EVICTING);
460 ASSERT(!MUTEX_HELD(&db->db_mtx));
462 mutex_enter(DBUF_HASH_MUTEX(h, idx));
463 dbp = &h->hash_table[idx];
464 while ((dbf = *dbp) != db) {
465 dbp = &dbf->db_hash_next;
468 *dbp = db->db_hash_next;
469 db->db_hash_next = NULL;
470 if (h->hash_table[idx] &&
471 h->hash_table[idx]->db_hash_next == NULL)
472 DBUF_STAT_BUMPDOWN(hash_chains);
473 mutex_exit(DBUF_HASH_MUTEX(h, idx));
474 atomic_dec_64(&dbuf_hash_count);
480 } dbvu_verify_type_t;
483 dbuf_verify_user(dmu_buf_impl_t *db, dbvu_verify_type_t verify_type)
488 if (db->db_user == NULL)
491 /* Only data blocks support the attachment of user data. */
492 ASSERT(db->db_level == 0);
494 /* Clients must resolve a dbuf before attaching user data. */
495 ASSERT(db->db.db_data != NULL);
496 ASSERT3U(db->db_state, ==, DB_CACHED);
498 holds = zfs_refcount_count(&db->db_holds);
499 if (verify_type == DBVU_EVICTING) {
501 * Immediate eviction occurs when holds == dirtycnt.
502 * For normal eviction buffers, holds is zero on
503 * eviction, except when dbuf_fix_old_data() calls
504 * dbuf_clear_data(). However, the hold count can grow
505 * during eviction even though db_mtx is held (see
506 * dmu_bonus_hold() for an example), so we can only
507 * test the generic invariant that holds >= dirtycnt.
509 ASSERT3U(holds, >=, db->db_dirtycnt);
511 if (db->db_user_immediate_evict == TRUE)
512 ASSERT3U(holds, >=, db->db_dirtycnt);
514 ASSERT3U(holds, >, 0);
520 dbuf_evict_user(dmu_buf_impl_t *db)
522 dmu_buf_user_t *dbu = db->db_user;
524 ASSERT(MUTEX_HELD(&db->db_mtx));
529 dbuf_verify_user(db, DBVU_EVICTING);
533 if (dbu->dbu_clear_on_evict_dbufp != NULL)
534 *dbu->dbu_clear_on_evict_dbufp = NULL;
538 * There are two eviction callbacks - one that we call synchronously
539 * and one that we invoke via a taskq. The async one is useful for
540 * avoiding lock order reversals and limiting stack depth.
542 * Note that if we have a sync callback but no async callback,
543 * it's likely that the sync callback will free the structure
544 * containing the dbu. In that case we need to take care to not
545 * dereference dbu after calling the sync evict func.
547 boolean_t has_async = (dbu->dbu_evict_func_async != NULL);
549 if (dbu->dbu_evict_func_sync != NULL)
550 dbu->dbu_evict_func_sync(dbu);
553 taskq_dispatch_ent(dbu_evict_taskq, dbu->dbu_evict_func_async,
554 dbu, 0, &dbu->dbu_tqent);
559 dbuf_is_metadata(dmu_buf_impl_t *db)
562 * Consider indirect blocks and spill blocks to be meta data.
564 if (db->db_level > 0 || db->db_blkid == DMU_SPILL_BLKID) {
567 boolean_t is_metadata;
570 is_metadata = DMU_OT_IS_METADATA(DB_DNODE(db)->dn_type);
573 return (is_metadata);
579 * This function *must* return indices evenly distributed between all
580 * sublists of the multilist. This is needed due to how the dbuf eviction
581 * code is laid out; dbuf_evict_thread() assumes dbufs are evenly
582 * distributed between all sublists and uses this assumption when
583 * deciding which sublist to evict from and how much to evict from it.
586 dbuf_cache_multilist_index_func(multilist_t *ml, void *obj)
588 dmu_buf_impl_t *db = obj;
591 * The assumption here, is the hash value for a given
592 * dmu_buf_impl_t will remain constant throughout it's lifetime
593 * (i.e. it's objset, object, level and blkid fields don't change).
594 * Thus, we don't need to store the dbuf's sublist index
595 * on insertion, as this index can be recalculated on removal.
597 * Also, the low order bits of the hash value are thought to be
598 * distributed evenly. Otherwise, in the case that the multilist
599 * has a power of two number of sublists, each sublists' usage
600 * would not be evenly distributed.
602 return (dbuf_hash(db->db_objset, db->db.db_object,
603 db->db_level, db->db_blkid) %
604 multilist_get_num_sublists(ml));
607 static inline unsigned long
608 dbuf_cache_target_bytes(void)
610 return MIN(dbuf_cache_max_bytes,
611 arc_target_bytes() >> dbuf_cache_shift);
614 static inline uint64_t
615 dbuf_cache_hiwater_bytes(void)
617 uint64_t dbuf_cache_target = dbuf_cache_target_bytes();
618 return (dbuf_cache_target +
619 (dbuf_cache_target * dbuf_cache_hiwater_pct) / 100);
622 static inline uint64_t
623 dbuf_cache_lowater_bytes(void)
625 uint64_t dbuf_cache_target = dbuf_cache_target_bytes();
626 return (dbuf_cache_target -
627 (dbuf_cache_target * dbuf_cache_lowater_pct) / 100);
630 static inline boolean_t
631 dbuf_cache_above_hiwater(void)
633 return (zfs_refcount_count(&dbuf_caches[DB_DBUF_CACHE].size) >
634 dbuf_cache_hiwater_bytes());
637 static inline boolean_t
638 dbuf_cache_above_lowater(void)
640 return (zfs_refcount_count(&dbuf_caches[DB_DBUF_CACHE].size) >
641 dbuf_cache_lowater_bytes());
645 * Evict the oldest eligible dbuf from the dbuf cache.
650 int idx = multilist_get_random_index(dbuf_caches[DB_DBUF_CACHE].cache);
651 multilist_sublist_t *mls = multilist_sublist_lock(
652 dbuf_caches[DB_DBUF_CACHE].cache, idx);
654 ASSERT(!MUTEX_HELD(&dbuf_evict_lock));
656 dmu_buf_impl_t *db = multilist_sublist_tail(mls);
657 while (db != NULL && mutex_tryenter(&db->db_mtx) == 0) {
658 db = multilist_sublist_prev(mls, db);
661 DTRACE_PROBE2(dbuf__evict__one, dmu_buf_impl_t *, db,
662 multilist_sublist_t *, mls);
665 multilist_sublist_remove(mls, db);
666 multilist_sublist_unlock(mls);
667 (void) zfs_refcount_remove_many(
668 &dbuf_caches[DB_DBUF_CACHE].size, db->db.db_size, db);
669 DBUF_STAT_BUMPDOWN(cache_levels[db->db_level]);
670 DBUF_STAT_BUMPDOWN(cache_count);
671 DBUF_STAT_DECR(cache_levels_bytes[db->db_level],
673 ASSERT3U(db->db_caching_status, ==, DB_DBUF_CACHE);
674 db->db_caching_status = DB_NO_CACHE;
676 DBUF_STAT_MAX(cache_size_bytes_max,
677 zfs_refcount_count(&dbuf_caches[DB_DBUF_CACHE].size));
678 DBUF_STAT_BUMP(cache_total_evicts);
680 multilist_sublist_unlock(mls);
685 * The dbuf evict thread is responsible for aging out dbufs from the
686 * cache. Once the cache has reached it's maximum size, dbufs are removed
687 * and destroyed. The eviction thread will continue running until the size
688 * of the dbuf cache is at or below the maximum size. Once the dbuf is aged
689 * out of the cache it is destroyed and becomes eligible for arc eviction.
693 dbuf_evict_thread(void *unused)
697 CALLB_CPR_INIT(&cpr, &dbuf_evict_lock, callb_generic_cpr, FTAG);
699 mutex_enter(&dbuf_evict_lock);
700 while (!dbuf_evict_thread_exit) {
701 while (!dbuf_cache_above_lowater() && !dbuf_evict_thread_exit) {
702 CALLB_CPR_SAFE_BEGIN(&cpr);
703 (void) cv_timedwait_sig_hires(&dbuf_evict_cv,
704 &dbuf_evict_lock, SEC2NSEC(1), MSEC2NSEC(1), 0);
705 CALLB_CPR_SAFE_END(&cpr, &dbuf_evict_lock);
707 mutex_exit(&dbuf_evict_lock);
710 * Keep evicting as long as we're above the low water mark
711 * for the cache. We do this without holding the locks to
712 * minimize lock contention.
714 while (dbuf_cache_above_lowater() && !dbuf_evict_thread_exit) {
718 mutex_enter(&dbuf_evict_lock);
721 dbuf_evict_thread_exit = B_FALSE;
722 cv_broadcast(&dbuf_evict_cv);
723 CALLB_CPR_EXIT(&cpr); /* drops dbuf_evict_lock */
728 * Wake up the dbuf eviction thread if the dbuf cache is at its max size.
729 * If the dbuf cache is at its high water mark, then evict a dbuf from the
730 * dbuf cache using the callers context.
733 dbuf_evict_notify(void)
736 * We check if we should evict without holding the dbuf_evict_lock,
737 * because it's OK to occasionally make the wrong decision here,
738 * and grabbing the lock results in massive lock contention.
740 if (zfs_refcount_count(&dbuf_caches[DB_DBUF_CACHE].size) >
741 dbuf_cache_target_bytes()) {
742 if (dbuf_cache_above_hiwater())
744 cv_signal(&dbuf_evict_cv);
749 dbuf_kstat_update(kstat_t *ksp, int rw)
751 dbuf_stats_t *ds = ksp->ks_data;
753 if (rw == KSTAT_WRITE) {
754 return (SET_ERROR(EACCES));
756 ds->metadata_cache_size_bytes.value.ui64 = zfs_refcount_count(
757 &dbuf_caches[DB_DBUF_METADATA_CACHE].size);
758 ds->cache_size_bytes.value.ui64 =
759 zfs_refcount_count(&dbuf_caches[DB_DBUF_CACHE].size);
760 ds->cache_target_bytes.value.ui64 = dbuf_cache_target_bytes();
761 ds->cache_hiwater_bytes.value.ui64 = dbuf_cache_hiwater_bytes();
762 ds->cache_lowater_bytes.value.ui64 = dbuf_cache_lowater_bytes();
763 ds->hash_elements.value.ui64 = dbuf_hash_count;
772 uint64_t hsize = 1ULL << 16;
773 dbuf_hash_table_t *h = &dbuf_hash_table;
777 * The hash table is big enough to fill all of physical memory
778 * with an average block size of zfs_arc_average_blocksize (default 8K).
779 * By default, the table will take up
780 * totalmem * sizeof(void*) / 8K (1MB per GB with 8-byte pointers).
782 while (hsize * zfs_arc_average_blocksize < physmem * PAGESIZE)
786 h->hash_table_mask = hsize - 1;
789 * Large allocations which do not require contiguous pages
790 * should be using vmem_alloc() in the linux kernel
792 h->hash_table = vmem_zalloc(hsize * sizeof (void *), KM_SLEEP);
794 h->hash_table = kmem_zalloc(hsize * sizeof (void *), KM_NOSLEEP);
796 if (h->hash_table == NULL) {
797 /* XXX - we should really return an error instead of assert */
798 ASSERT(hsize > (1ULL << 10));
803 dbuf_kmem_cache = kmem_cache_create("dmu_buf_impl_t",
804 sizeof (dmu_buf_impl_t),
805 0, dbuf_cons, dbuf_dest, NULL, NULL, NULL, 0);
807 for (i = 0; i < DBUF_MUTEXES; i++)
808 mutex_init(&h->hash_mutexes[i], NULL, MUTEX_DEFAULT, NULL);
813 * Setup the parameters for the dbuf caches. We set the sizes of the
814 * dbuf cache and the metadata cache to 1/32nd and 1/16th (default)
815 * of the target size of the ARC. If the values has been specified as
816 * a module option and they're not greater than the target size of the
817 * ARC, then we honor that value.
819 if (dbuf_cache_max_bytes == 0 ||
820 dbuf_cache_max_bytes >= arc_target_bytes()) {
821 dbuf_cache_max_bytes = arc_target_bytes() >> dbuf_cache_shift;
823 if (dbuf_metadata_cache_max_bytes == 0 ||
824 dbuf_metadata_cache_max_bytes >= arc_target_bytes()) {
825 dbuf_metadata_cache_max_bytes =
826 arc_target_bytes() >> dbuf_metadata_cache_shift;
830 * All entries are queued via taskq_dispatch_ent(), so min/maxalloc
831 * configuration is not required.
833 dbu_evict_taskq = taskq_create("dbu_evict", 1, defclsyspri, 0, 0, 0);
835 for (dbuf_cached_state_t dcs = 0; dcs < DB_CACHE_MAX; dcs++) {
836 dbuf_caches[dcs].cache =
837 multilist_create(sizeof (dmu_buf_impl_t),
838 offsetof(dmu_buf_impl_t, db_cache_link),
839 dbuf_cache_multilist_index_func);
840 zfs_refcount_create(&dbuf_caches[dcs].size);
843 dbuf_evict_thread_exit = B_FALSE;
844 mutex_init(&dbuf_evict_lock, NULL, MUTEX_DEFAULT, NULL);
845 cv_init(&dbuf_evict_cv, NULL, CV_DEFAULT, NULL);
846 dbuf_cache_evict_thread = thread_create(NULL, 0, dbuf_evict_thread,
847 NULL, 0, &p0, TS_RUN, minclsyspri);
849 dbuf_ksp = kstat_create("zfs", 0, "dbufstats", "misc",
850 KSTAT_TYPE_NAMED, sizeof (dbuf_stats) / sizeof (kstat_named_t),
852 if (dbuf_ksp != NULL) {
853 for (i = 0; i < DN_MAX_LEVELS; i++) {
854 snprintf(dbuf_stats.cache_levels[i].name,
855 KSTAT_STRLEN, "cache_level_%d", i);
856 dbuf_stats.cache_levels[i].data_type =
858 snprintf(dbuf_stats.cache_levels_bytes[i].name,
859 KSTAT_STRLEN, "cache_level_%d_bytes", i);
860 dbuf_stats.cache_levels_bytes[i].data_type =
863 dbuf_ksp->ks_data = &dbuf_stats;
864 dbuf_ksp->ks_update = dbuf_kstat_update;
865 kstat_install(dbuf_ksp);
872 dbuf_hash_table_t *h = &dbuf_hash_table;
875 dbuf_stats_destroy();
877 for (i = 0; i < DBUF_MUTEXES; i++)
878 mutex_destroy(&h->hash_mutexes[i]);
881 * Large allocations which do not require contiguous pages
882 * should be using vmem_free() in the linux kernel
884 vmem_free(h->hash_table, (h->hash_table_mask + 1) * sizeof (void *));
886 kmem_free(h->hash_table, (h->hash_table_mask + 1) * sizeof (void *));
888 kmem_cache_destroy(dbuf_kmem_cache);
889 taskq_destroy(dbu_evict_taskq);
891 mutex_enter(&dbuf_evict_lock);
892 dbuf_evict_thread_exit = B_TRUE;
893 while (dbuf_evict_thread_exit) {
894 cv_signal(&dbuf_evict_cv);
895 cv_wait(&dbuf_evict_cv, &dbuf_evict_lock);
897 mutex_exit(&dbuf_evict_lock);
899 mutex_destroy(&dbuf_evict_lock);
900 cv_destroy(&dbuf_evict_cv);
902 for (dbuf_cached_state_t dcs = 0; dcs < DB_CACHE_MAX; dcs++) {
903 zfs_refcount_destroy(&dbuf_caches[dcs].size);
904 multilist_destroy(dbuf_caches[dcs].cache);
907 if (dbuf_ksp != NULL) {
908 kstat_delete(dbuf_ksp);
919 dbuf_verify(dmu_buf_impl_t *db)
922 dbuf_dirty_record_t *dr;
924 ASSERT(MUTEX_HELD(&db->db_mtx));
926 if (!(zfs_flags & ZFS_DEBUG_DBUF_VERIFY))
929 ASSERT(db->db_objset != NULL);
933 ASSERT(db->db_parent == NULL);
934 ASSERT(db->db_blkptr == NULL);
936 ASSERT3U(db->db.db_object, ==, dn->dn_object);
937 ASSERT3P(db->db_objset, ==, dn->dn_objset);
938 ASSERT3U(db->db_level, <, dn->dn_nlevels);
939 ASSERT(db->db_blkid == DMU_BONUS_BLKID ||
940 db->db_blkid == DMU_SPILL_BLKID ||
941 !avl_is_empty(&dn->dn_dbufs));
943 if (db->db_blkid == DMU_BONUS_BLKID) {
945 ASSERT3U(db->db.db_size, >=, dn->dn_bonuslen);
946 ASSERT3U(db->db.db_offset, ==, DMU_BONUS_BLKID);
947 } else if (db->db_blkid == DMU_SPILL_BLKID) {
949 ASSERT0(db->db.db_offset);
951 ASSERT3U(db->db.db_offset, ==, db->db_blkid * db->db.db_size);
954 for (dr = db->db_data_pending; dr != NULL; dr = dr->dr_next)
955 ASSERT(dr->dr_dbuf == db);
957 for (dr = db->db_last_dirty; dr != NULL; dr = dr->dr_next)
958 ASSERT(dr->dr_dbuf == db);
961 * We can't assert that db_size matches dn_datablksz because it
962 * can be momentarily different when another thread is doing
965 if (db->db_level == 0 && db->db.db_object == DMU_META_DNODE_OBJECT) {
966 dr = db->db_data_pending;
968 * It should only be modified in syncing context, so
969 * make sure we only have one copy of the data.
971 ASSERT(dr == NULL || dr->dt.dl.dr_data == db->db_buf);
974 /* verify db->db_blkptr */
976 if (db->db_parent == dn->dn_dbuf) {
977 /* db is pointed to by the dnode */
978 /* ASSERT3U(db->db_blkid, <, dn->dn_nblkptr); */
979 if (DMU_OBJECT_IS_SPECIAL(db->db.db_object))
980 ASSERT(db->db_parent == NULL);
982 ASSERT(db->db_parent != NULL);
983 if (db->db_blkid != DMU_SPILL_BLKID)
984 ASSERT3P(db->db_blkptr, ==,
985 &dn->dn_phys->dn_blkptr[db->db_blkid]);
987 /* db is pointed to by an indirect block */
988 int epb __maybe_unused = db->db_parent->db.db_size >>
990 ASSERT3U(db->db_parent->db_level, ==, db->db_level+1);
991 ASSERT3U(db->db_parent->db.db_object, ==,
994 * dnode_grow_indblksz() can make this fail if we don't
995 * have the parent's rwlock. XXX indblksz no longer
996 * grows. safe to do this now?
998 if (RW_LOCK_HELD(&db->db_parent->db_rwlock)) {
999 ASSERT3P(db->db_blkptr, ==,
1000 ((blkptr_t *)db->db_parent->db.db_data +
1001 db->db_blkid % epb));
1005 if ((db->db_blkptr == NULL || BP_IS_HOLE(db->db_blkptr)) &&
1006 (db->db_buf == NULL || db->db_buf->b_data) &&
1007 db->db.db_data && db->db_blkid != DMU_BONUS_BLKID &&
1008 db->db_state != DB_FILL && !dn->dn_free_txg) {
1010 * If the blkptr isn't set but they have nonzero data,
1011 * it had better be dirty, otherwise we'll lose that
1012 * data when we evict this buffer.
1014 * There is an exception to this rule for indirect blocks; in
1015 * this case, if the indirect block is a hole, we fill in a few
1016 * fields on each of the child blocks (importantly, birth time)
1017 * to prevent hole birth times from being lost when you
1018 * partially fill in a hole.
1020 if (db->db_dirtycnt == 0) {
1021 if (db->db_level == 0) {
1022 uint64_t *buf = db->db.db_data;
1025 for (i = 0; i < db->db.db_size >> 3; i++) {
1026 ASSERT(buf[i] == 0);
1029 blkptr_t *bps = db->db.db_data;
1030 ASSERT3U(1 << DB_DNODE(db)->dn_indblkshift, ==,
1033 * We want to verify that all the blkptrs in the
1034 * indirect block are holes, but we may have
1035 * automatically set up a few fields for them.
1036 * We iterate through each blkptr and verify
1037 * they only have those fields set.
1040 i < db->db.db_size / sizeof (blkptr_t);
1042 blkptr_t *bp = &bps[i];
1043 ASSERT(ZIO_CHECKSUM_IS_ZERO(
1046 DVA_IS_EMPTY(&bp->blk_dva[0]) &&
1047 DVA_IS_EMPTY(&bp->blk_dva[1]) &&
1048 DVA_IS_EMPTY(&bp->blk_dva[2]));
1049 ASSERT0(bp->blk_fill);
1050 ASSERT0(bp->blk_pad[0]);
1051 ASSERT0(bp->blk_pad[1]);
1052 ASSERT(!BP_IS_EMBEDDED(bp));
1053 ASSERT(BP_IS_HOLE(bp));
1054 ASSERT0(bp->blk_phys_birth);
1064 dbuf_clear_data(dmu_buf_impl_t *db)
1066 ASSERT(MUTEX_HELD(&db->db_mtx));
1067 dbuf_evict_user(db);
1068 ASSERT3P(db->db_buf, ==, NULL);
1069 db->db.db_data = NULL;
1070 if (db->db_state != DB_NOFILL)
1071 db->db_state = DB_UNCACHED;
1075 dbuf_set_data(dmu_buf_impl_t *db, arc_buf_t *buf)
1077 ASSERT(MUTEX_HELD(&db->db_mtx));
1078 ASSERT(buf != NULL);
1081 ASSERT(buf->b_data != NULL);
1082 db->db.db_data = buf->b_data;
1086 * Loan out an arc_buf for read. Return the loaned arc_buf.
1089 dbuf_loan_arcbuf(dmu_buf_impl_t *db)
1093 ASSERT(db->db_blkid != DMU_BONUS_BLKID);
1094 mutex_enter(&db->db_mtx);
1095 if (arc_released(db->db_buf) || zfs_refcount_count(&db->db_holds) > 1) {
1096 int blksz = db->db.db_size;
1097 spa_t *spa = db->db_objset->os_spa;
1099 mutex_exit(&db->db_mtx);
1100 abuf = arc_loan_buf(spa, B_FALSE, blksz);
1101 bcopy(db->db.db_data, abuf->b_data, blksz);
1104 arc_loan_inuse_buf(abuf, db);
1106 dbuf_clear_data(db);
1107 mutex_exit(&db->db_mtx);
1113 * Calculate which level n block references the data at the level 0 offset
1117 dbuf_whichblock(const dnode_t *dn, const int64_t level, const uint64_t offset)
1119 if (dn->dn_datablkshift != 0 && dn->dn_indblkshift != 0) {
1121 * The level n blkid is equal to the level 0 blkid divided by
1122 * the number of level 0s in a level n block.
1124 * The level 0 blkid is offset >> datablkshift =
1125 * offset / 2^datablkshift.
1127 * The number of level 0s in a level n is the number of block
1128 * pointers in an indirect block, raised to the power of level.
1129 * This is 2^(indblkshift - SPA_BLKPTRSHIFT)^level =
1130 * 2^(level*(indblkshift - SPA_BLKPTRSHIFT)).
1132 * Thus, the level n blkid is: offset /
1133 * ((2^datablkshift)*(2^(level*(indblkshift-SPA_BLKPTRSHIFT))))
1134 * = offset / 2^(datablkshift + level *
1135 * (indblkshift - SPA_BLKPTRSHIFT))
1136 * = offset >> (datablkshift + level *
1137 * (indblkshift - SPA_BLKPTRSHIFT))
1140 const unsigned exp = dn->dn_datablkshift +
1141 level * (dn->dn_indblkshift - SPA_BLKPTRSHIFT);
1143 if (exp >= 8 * sizeof (offset)) {
1144 /* This only happens on the highest indirection level */
1145 ASSERT3U(level, ==, dn->dn_nlevels - 1);
1149 ASSERT3U(exp, <, 8 * sizeof (offset));
1151 return (offset >> exp);
1153 ASSERT3U(offset, <, dn->dn_datablksz);
1159 * This function is used to lock the parent of the provided dbuf. This should be
1160 * used when modifying or reading db_blkptr.
1163 dmu_buf_lock_parent(dmu_buf_impl_t *db, krw_t rw, void *tag)
1165 enum db_lock_type ret = DLT_NONE;
1166 if (db->db_parent != NULL) {
1167 rw_enter(&db->db_parent->db_rwlock, rw);
1169 } else if (dmu_objset_ds(db->db_objset) != NULL) {
1170 rrw_enter(&dmu_objset_ds(db->db_objset)->ds_bp_rwlock, rw,
1175 * We only return a DLT_NONE lock when it's the top-most indirect block
1176 * of the meta-dnode of the MOS.
1182 * We need to pass the lock type in because it's possible that the block will
1183 * move from being the topmost indirect block in a dnode (and thus, have no
1184 * parent) to not the top-most via an indirection increase. This would cause a
1185 * panic if we didn't pass the lock type in.
1188 dmu_buf_unlock_parent(dmu_buf_impl_t *db, db_lock_type_t type, void *tag)
1190 if (type == DLT_PARENT)
1191 rw_exit(&db->db_parent->db_rwlock);
1192 else if (type == DLT_OBJSET)
1193 rrw_exit(&dmu_objset_ds(db->db_objset)->ds_bp_rwlock, tag);
1197 dbuf_read_done(zio_t *zio, const zbookmark_phys_t *zb, const blkptr_t *bp,
1198 arc_buf_t *buf, void *vdb)
1200 dmu_buf_impl_t *db = vdb;
1202 mutex_enter(&db->db_mtx);
1203 ASSERT3U(db->db_state, ==, DB_READ);
1205 * All reads are synchronous, so we must have a hold on the dbuf
1207 ASSERT(zfs_refcount_count(&db->db_holds) > 0);
1208 ASSERT(db->db_buf == NULL);
1209 ASSERT(db->db.db_data == NULL);
1212 ASSERT(zio == NULL || zio->io_error != 0);
1213 ASSERT(db->db_blkid != DMU_BONUS_BLKID);
1214 ASSERT3P(db->db_buf, ==, NULL);
1215 db->db_state = DB_UNCACHED;
1216 } else if (db->db_level == 0 && db->db_freed_in_flight) {
1217 /* freed in flight */
1218 ASSERT(zio == NULL || zio->io_error == 0);
1219 arc_release(buf, db);
1220 bzero(buf->b_data, db->db.db_size);
1221 arc_buf_freeze(buf);
1222 db->db_freed_in_flight = FALSE;
1223 dbuf_set_data(db, buf);
1224 db->db_state = DB_CACHED;
1227 ASSERT(zio == NULL || zio->io_error == 0);
1228 dbuf_set_data(db, buf);
1229 db->db_state = DB_CACHED;
1231 cv_broadcast(&db->db_changed);
1232 dbuf_rele_and_unlock(db, NULL, B_FALSE);
1237 * This function ensures that, when doing a decrypting read of a block,
1238 * we make sure we have decrypted the dnode associated with it. We must do
1239 * this so that we ensure we are fully authenticating the checksum-of-MACs
1240 * tree from the root of the objset down to this block. Indirect blocks are
1241 * always verified against their secure checksum-of-MACs assuming that the
1242 * dnode containing them is correct. Now that we are doing a decrypting read,
1243 * we can be sure that the key is loaded and verify that assumption. This is
1244 * especially important considering that we always read encrypted dnode
1245 * blocks as raw data (without verifying their MACs) to start, and
1246 * decrypt / authenticate them when we need to read an encrypted bonus buffer.
1249 dbuf_read_verify_dnode_crypt(dmu_buf_impl_t *db, uint32_t flags)
1252 objset_t *os = db->db_objset;
1253 arc_buf_t *dnode_abuf;
1255 zbookmark_phys_t zb;
1257 ASSERT(MUTEX_HELD(&db->db_mtx));
1259 if (!os->os_encrypted || os->os_raw_receive ||
1260 (flags & DB_RF_NO_DECRYPT) != 0)
1265 dnode_abuf = (dn->dn_dbuf != NULL) ? dn->dn_dbuf->db_buf : NULL;
1267 if (dnode_abuf == NULL || !arc_is_encrypted(dnode_abuf)) {
1272 SET_BOOKMARK(&zb, dmu_objset_id(os),
1273 DMU_META_DNODE_OBJECT, 0, dn->dn_dbuf->db_blkid);
1274 err = arc_untransform(dnode_abuf, os->os_spa, &zb, B_TRUE);
1277 * An error code of EACCES tells us that the key is still not
1278 * available. This is ok if we are only reading authenticated
1279 * (and therefore non-encrypted) blocks.
1281 if (err == EACCES && ((db->db_blkid != DMU_BONUS_BLKID &&
1282 !DMU_OT_IS_ENCRYPTED(dn->dn_type)) ||
1283 (db->db_blkid == DMU_BONUS_BLKID &&
1284 !DMU_OT_IS_ENCRYPTED(dn->dn_bonustype))))
1293 * Drops db_mtx and the parent lock specified by dblt and tag before
1297 dbuf_read_impl(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags,
1298 db_lock_type_t dblt, void *tag)
1301 zbookmark_phys_t zb;
1302 uint32_t aflags = ARC_FLAG_NOWAIT;
1303 int err, zio_flags = 0;
1307 ASSERT(!zfs_refcount_is_zero(&db->db_holds));
1308 ASSERT(MUTEX_HELD(&db->db_mtx));
1309 ASSERT(db->db_state == DB_UNCACHED);
1310 ASSERT(db->db_buf == NULL);
1311 ASSERT(db->db_parent == NULL ||
1312 RW_LOCK_HELD(&db->db_parent->db_rwlock));
1314 if (db->db_blkid == DMU_BONUS_BLKID) {
1316 * The bonus length stored in the dnode may be less than
1317 * the maximum available space in the bonus buffer.
1319 int bonuslen = MIN(dn->dn_bonuslen, dn->dn_phys->dn_bonuslen);
1320 int max_bonuslen = DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots);
1322 /* if the underlying dnode block is encrypted, decrypt it */
1323 err = dbuf_read_verify_dnode_crypt(db, flags);
1326 mutex_exit(&db->db_mtx);
1330 ASSERT3U(bonuslen, <=, db->db.db_size);
1331 db->db.db_data = kmem_alloc(max_bonuslen, KM_SLEEP);
1332 arc_space_consume(max_bonuslen, ARC_SPACE_BONUS);
1333 if (bonuslen < max_bonuslen)
1334 bzero(db->db.db_data, max_bonuslen);
1336 bcopy(DN_BONUS(dn->dn_phys), db->db.db_data, bonuslen);
1338 db->db_state = DB_CACHED;
1339 mutex_exit(&db->db_mtx);
1340 dmu_buf_unlock_parent(db, dblt, tag);
1345 * Recheck BP_IS_HOLE() after dnode_block_freed() in case dnode_sync()
1346 * processes the delete record and clears the bp while we are waiting
1347 * for the dn_mtx (resulting in a "no" from block_freed).
1349 if (db->db_blkptr == NULL || BP_IS_HOLE(db->db_blkptr) ||
1350 (db->db_level == 0 && (dnode_block_freed(dn, db->db_blkid) ||
1351 BP_IS_HOLE(db->db_blkptr)))) {
1352 arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db);
1354 dbuf_set_data(db, arc_alloc_buf(db->db_objset->os_spa, db, type,
1356 bzero(db->db.db_data, db->db.db_size);
1358 if (db->db_blkptr != NULL && db->db_level > 0 &&
1359 BP_IS_HOLE(db->db_blkptr) &&
1360 db->db_blkptr->blk_birth != 0) {
1361 blkptr_t *bps = db->db.db_data;
1362 for (int i = 0; i < ((1 <<
1363 DB_DNODE(db)->dn_indblkshift) / sizeof (blkptr_t));
1365 blkptr_t *bp = &bps[i];
1366 ASSERT3U(BP_GET_LSIZE(db->db_blkptr), ==,
1367 1 << dn->dn_indblkshift);
1369 BP_GET_LEVEL(db->db_blkptr) == 1 ?
1371 BP_GET_LSIZE(db->db_blkptr));
1372 BP_SET_TYPE(bp, BP_GET_TYPE(db->db_blkptr));
1374 BP_GET_LEVEL(db->db_blkptr) - 1);
1375 BP_SET_BIRTH(bp, db->db_blkptr->blk_birth, 0);
1379 db->db_state = DB_CACHED;
1380 mutex_exit(&db->db_mtx);
1381 dmu_buf_unlock_parent(db, dblt, tag);
1386 * Any attempt to read a redacted block should result in an error. This
1387 * will never happen under normal conditions, but can be useful for
1388 * debugging purposes.
1390 if (BP_IS_REDACTED(db->db_blkptr)) {
1391 ASSERT(dsl_dataset_feature_is_active(
1392 db->db_objset->os_dsl_dataset,
1393 SPA_FEATURE_REDACTED_DATASETS));
1395 mutex_exit(&db->db_mtx);
1396 return (SET_ERROR(EIO));
1400 SET_BOOKMARK(&zb, dmu_objset_id(db->db_objset),
1401 db->db.db_object, db->db_level, db->db_blkid);
1404 * All bps of an encrypted os should have the encryption bit set.
1405 * If this is not true it indicates tampering and we report an error.
1407 if (db->db_objset->os_encrypted && !BP_USES_CRYPT(db->db_blkptr)) {
1408 spa_log_error(db->db_objset->os_spa, &zb);
1409 zfs_panic_recover("unencrypted block in encrypted "
1410 "object set %llu", dmu_objset_id(db->db_objset));
1412 mutex_exit(&db->db_mtx);
1413 dmu_buf_unlock_parent(db, dblt, tag);
1414 return (SET_ERROR(EIO));
1417 err = dbuf_read_verify_dnode_crypt(db, flags);
1420 dmu_buf_unlock_parent(db, dblt, tag);
1421 mutex_exit(&db->db_mtx);
1427 db->db_state = DB_READ;
1428 mutex_exit(&db->db_mtx);
1430 if (DBUF_IS_L2CACHEABLE(db))
1431 aflags |= ARC_FLAG_L2CACHE;
1433 dbuf_add_ref(db, NULL);
1435 zio_flags = (flags & DB_RF_CANFAIL) ?
1436 ZIO_FLAG_CANFAIL : ZIO_FLAG_MUSTSUCCEED;
1438 if ((flags & DB_RF_NO_DECRYPT) && BP_IS_PROTECTED(db->db_blkptr))
1439 zio_flags |= ZIO_FLAG_RAW;
1441 * The zio layer will copy the provided blkptr later, but we need to
1442 * do this now so that we can release the parent's rwlock. We have to
1443 * do that now so that if dbuf_read_done is called synchronously (on
1444 * an l1 cache hit) we don't acquire the db_mtx while holding the
1445 * parent's rwlock, which would be a lock ordering violation.
1447 blkptr_t bp = *db->db_blkptr;
1448 dmu_buf_unlock_parent(db, dblt, tag);
1449 (void) arc_read(zio, db->db_objset->os_spa, &bp,
1450 dbuf_read_done, db, ZIO_PRIORITY_SYNC_READ, zio_flags,
1456 * This is our just-in-time copy function. It makes a copy of buffers that
1457 * have been modified in a previous transaction group before we access them in
1458 * the current active group.
1460 * This function is used in three places: when we are dirtying a buffer for the
1461 * first time in a txg, when we are freeing a range in a dnode that includes
1462 * this buffer, and when we are accessing a buffer which was received compressed
1463 * and later referenced in a WRITE_BYREF record.
1465 * Note that when we are called from dbuf_free_range() we do not put a hold on
1466 * the buffer, we just traverse the active dbuf list for the dnode.
1469 dbuf_fix_old_data(dmu_buf_impl_t *db, uint64_t txg)
1471 dbuf_dirty_record_t *dr = db->db_last_dirty;
1473 ASSERT(MUTEX_HELD(&db->db_mtx));
1474 ASSERT(db->db.db_data != NULL);
1475 ASSERT(db->db_level == 0);
1476 ASSERT(db->db.db_object != DMU_META_DNODE_OBJECT);
1479 (dr->dt.dl.dr_data !=
1480 ((db->db_blkid == DMU_BONUS_BLKID) ? db->db.db_data : db->db_buf)))
1484 * If the last dirty record for this dbuf has not yet synced
1485 * and its referencing the dbuf data, either:
1486 * reset the reference to point to a new copy,
1487 * or (if there a no active holders)
1488 * just null out the current db_data pointer.
1490 ASSERT3U(dr->dr_txg, >=, txg - 2);
1491 if (db->db_blkid == DMU_BONUS_BLKID) {
1492 dnode_t *dn = DB_DNODE(db);
1493 int bonuslen = DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots);
1494 dr->dt.dl.dr_data = kmem_alloc(bonuslen, KM_SLEEP);
1495 arc_space_consume(bonuslen, ARC_SPACE_BONUS);
1496 bcopy(db->db.db_data, dr->dt.dl.dr_data, bonuslen);
1497 } else if (zfs_refcount_count(&db->db_holds) > db->db_dirtycnt) {
1498 dnode_t *dn = DB_DNODE(db);
1499 int size = arc_buf_size(db->db_buf);
1500 arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db);
1501 spa_t *spa = db->db_objset->os_spa;
1502 enum zio_compress compress_type =
1503 arc_get_compression(db->db_buf);
1505 if (arc_is_encrypted(db->db_buf)) {
1506 boolean_t byteorder;
1507 uint8_t salt[ZIO_DATA_SALT_LEN];
1508 uint8_t iv[ZIO_DATA_IV_LEN];
1509 uint8_t mac[ZIO_DATA_MAC_LEN];
1511 arc_get_raw_params(db->db_buf, &byteorder, salt,
1513 dr->dt.dl.dr_data = arc_alloc_raw_buf(spa, db,
1514 dmu_objset_id(dn->dn_objset), byteorder, salt, iv,
1515 mac, dn->dn_type, size, arc_buf_lsize(db->db_buf),
1517 } else if (compress_type != ZIO_COMPRESS_OFF) {
1518 ASSERT3U(type, ==, ARC_BUFC_DATA);
1519 dr->dt.dl.dr_data = arc_alloc_compressed_buf(spa, db,
1520 size, arc_buf_lsize(db->db_buf), compress_type);
1522 dr->dt.dl.dr_data = arc_alloc_buf(spa, db, type, size);
1524 bcopy(db->db.db_data, dr->dt.dl.dr_data->b_data, size);
1527 dbuf_clear_data(db);
1532 dbuf_read(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags)
1539 * We don't have to hold the mutex to check db_state because it
1540 * can't be freed while we have a hold on the buffer.
1542 ASSERT(!zfs_refcount_is_zero(&db->db_holds));
1544 if (db->db_state == DB_NOFILL)
1545 return (SET_ERROR(EIO));
1550 prefetch = db->db_level == 0 && db->db_blkid != DMU_BONUS_BLKID &&
1551 (flags & DB_RF_NOPREFETCH) == 0 && dn != NULL &&
1552 DBUF_IS_CACHEABLE(db);
1554 mutex_enter(&db->db_mtx);
1555 if (db->db_state == DB_CACHED) {
1556 spa_t *spa = dn->dn_objset->os_spa;
1559 * Ensure that this block's dnode has been decrypted if
1560 * the caller has requested decrypted data.
1562 err = dbuf_read_verify_dnode_crypt(db, flags);
1565 * If the arc buf is compressed or encrypted and the caller
1566 * requested uncompressed data, we need to untransform it
1567 * before returning. We also call arc_untransform() on any
1568 * unauthenticated blocks, which will verify their MAC if
1569 * the key is now available.
1571 if (err == 0 && db->db_buf != NULL &&
1572 (flags & DB_RF_NO_DECRYPT) == 0 &&
1573 (arc_is_encrypted(db->db_buf) ||
1574 arc_is_unauthenticated(db->db_buf) ||
1575 arc_get_compression(db->db_buf) != ZIO_COMPRESS_OFF)) {
1576 zbookmark_phys_t zb;
1578 SET_BOOKMARK(&zb, dmu_objset_id(db->db_objset),
1579 db->db.db_object, db->db_level, db->db_blkid);
1580 dbuf_fix_old_data(db, spa_syncing_txg(spa));
1581 err = arc_untransform(db->db_buf, spa, &zb, B_FALSE);
1582 dbuf_set_data(db, db->db_buf);
1584 mutex_exit(&db->db_mtx);
1585 if (err == 0 && prefetch) {
1586 dmu_zfetch(&dn->dn_zfetch, db->db_blkid, 1, B_TRUE,
1587 flags & DB_RF_HAVESTRUCT);
1590 DBUF_STAT_BUMP(hash_hits);
1591 } else if (db->db_state == DB_UNCACHED) {
1592 spa_t *spa = dn->dn_objset->os_spa;
1593 boolean_t need_wait = B_FALSE;
1595 db_lock_type_t dblt = dmu_buf_lock_parent(db, RW_READER, FTAG);
1598 db->db_blkptr != NULL && !BP_IS_HOLE(db->db_blkptr)) {
1599 zio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL);
1602 err = dbuf_read_impl(db, zio, flags, dblt, FTAG);
1604 * dbuf_read_impl has dropped db_mtx and our parent's rwlock
1607 if (!err && prefetch) {
1608 dmu_zfetch(&dn->dn_zfetch, db->db_blkid, 1, B_TRUE,
1609 flags & DB_RF_HAVESTRUCT);
1613 DBUF_STAT_BUMP(hash_misses);
1616 * If we created a zio_root we must execute it to avoid
1617 * leaking it, even if it isn't attached to any work due
1618 * to an error in dbuf_read_impl().
1622 err = zio_wait(zio);
1624 VERIFY0(zio_wait(zio));
1628 * Another reader came in while the dbuf was in flight
1629 * between UNCACHED and CACHED. Either a writer will finish
1630 * writing the buffer (sending the dbuf to CACHED) or the
1631 * first reader's request will reach the read_done callback
1632 * and send the dbuf to CACHED. Otherwise, a failure
1633 * occurred and the dbuf went to UNCACHED.
1635 mutex_exit(&db->db_mtx);
1637 dmu_zfetch(&dn->dn_zfetch, db->db_blkid, 1, B_TRUE,
1638 flags & DB_RF_HAVESTRUCT);
1641 DBUF_STAT_BUMP(hash_misses);
1643 /* Skip the wait per the caller's request. */
1644 mutex_enter(&db->db_mtx);
1645 if ((flags & DB_RF_NEVERWAIT) == 0) {
1646 while (db->db_state == DB_READ ||
1647 db->db_state == DB_FILL) {
1648 ASSERT(db->db_state == DB_READ ||
1649 (flags & DB_RF_HAVESTRUCT) == 0);
1650 DTRACE_PROBE2(blocked__read, dmu_buf_impl_t *,
1652 cv_wait(&db->db_changed, &db->db_mtx);
1654 if (db->db_state == DB_UNCACHED)
1655 err = SET_ERROR(EIO);
1657 mutex_exit(&db->db_mtx);
1664 dbuf_noread(dmu_buf_impl_t *db)
1666 ASSERT(!zfs_refcount_is_zero(&db->db_holds));
1667 ASSERT(db->db_blkid != DMU_BONUS_BLKID);
1668 mutex_enter(&db->db_mtx);
1669 while (db->db_state == DB_READ || db->db_state == DB_FILL)
1670 cv_wait(&db->db_changed, &db->db_mtx);
1671 if (db->db_state == DB_UNCACHED) {
1672 arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db);
1673 spa_t *spa = db->db_objset->os_spa;
1675 ASSERT(db->db_buf == NULL);
1676 ASSERT(db->db.db_data == NULL);
1677 dbuf_set_data(db, arc_alloc_buf(spa, db, type, db->db.db_size));
1678 db->db_state = DB_FILL;
1679 } else if (db->db_state == DB_NOFILL) {
1680 dbuf_clear_data(db);
1682 ASSERT3U(db->db_state, ==, DB_CACHED);
1684 mutex_exit(&db->db_mtx);
1688 dbuf_unoverride(dbuf_dirty_record_t *dr)
1690 dmu_buf_impl_t *db = dr->dr_dbuf;
1691 blkptr_t *bp = &dr->dt.dl.dr_overridden_by;
1692 uint64_t txg = dr->dr_txg;
1694 ASSERT(MUTEX_HELD(&db->db_mtx));
1696 * This assert is valid because dmu_sync() expects to be called by
1697 * a zilog's get_data while holding a range lock. This call only
1698 * comes from dbuf_dirty() callers who must also hold a range lock.
1700 ASSERT(dr->dt.dl.dr_override_state != DR_IN_DMU_SYNC);
1701 ASSERT(db->db_level == 0);
1703 if (db->db_blkid == DMU_BONUS_BLKID ||
1704 dr->dt.dl.dr_override_state == DR_NOT_OVERRIDDEN)
1707 ASSERT(db->db_data_pending != dr);
1709 /* free this block */
1710 if (!BP_IS_HOLE(bp) && !dr->dt.dl.dr_nopwrite)
1711 zio_free(db->db_objset->os_spa, txg, bp);
1713 dr->dt.dl.dr_override_state = DR_NOT_OVERRIDDEN;
1714 dr->dt.dl.dr_nopwrite = B_FALSE;
1715 dr->dt.dl.dr_has_raw_params = B_FALSE;
1718 * Release the already-written buffer, so we leave it in
1719 * a consistent dirty state. Note that all callers are
1720 * modifying the buffer, so they will immediately do
1721 * another (redundant) arc_release(). Therefore, leave
1722 * the buf thawed to save the effort of freezing &
1723 * immediately re-thawing it.
1725 arc_release(dr->dt.dl.dr_data, db);
1729 * Evict (if its unreferenced) or clear (if its referenced) any level-0
1730 * data blocks in the free range, so that any future readers will find
1734 dbuf_free_range(dnode_t *dn, uint64_t start_blkid, uint64_t end_blkid,
1737 dmu_buf_impl_t *db_search;
1738 dmu_buf_impl_t *db, *db_next;
1739 uint64_t txg = tx->tx_txg;
1742 if (end_blkid > dn->dn_maxblkid &&
1743 !(start_blkid == DMU_SPILL_BLKID || end_blkid == DMU_SPILL_BLKID))
1744 end_blkid = dn->dn_maxblkid;
1745 dprintf_dnode(dn, "start=%llu end=%llu\n", start_blkid, end_blkid);
1747 db_search = kmem_alloc(sizeof (dmu_buf_impl_t), KM_SLEEP);
1748 db_search->db_level = 0;
1749 db_search->db_blkid = start_blkid;
1750 db_search->db_state = DB_SEARCH;
1752 mutex_enter(&dn->dn_dbufs_mtx);
1753 db = avl_find(&dn->dn_dbufs, db_search, &where);
1754 ASSERT3P(db, ==, NULL);
1756 db = avl_nearest(&dn->dn_dbufs, where, AVL_AFTER);
1758 for (; db != NULL; db = db_next) {
1759 db_next = AVL_NEXT(&dn->dn_dbufs, db);
1760 ASSERT(db->db_blkid != DMU_BONUS_BLKID);
1762 if (db->db_level != 0 || db->db_blkid > end_blkid) {
1765 ASSERT3U(db->db_blkid, >=, start_blkid);
1767 /* found a level 0 buffer in the range */
1768 mutex_enter(&db->db_mtx);
1769 if (dbuf_undirty(db, tx)) {
1770 /* mutex has been dropped and dbuf destroyed */
1774 if (db->db_state == DB_UNCACHED ||
1775 db->db_state == DB_NOFILL ||
1776 db->db_state == DB_EVICTING) {
1777 ASSERT(db->db.db_data == NULL);
1778 mutex_exit(&db->db_mtx);
1781 if (db->db_state == DB_READ || db->db_state == DB_FILL) {
1782 /* will be handled in dbuf_read_done or dbuf_rele */
1783 db->db_freed_in_flight = TRUE;
1784 mutex_exit(&db->db_mtx);
1787 if (zfs_refcount_count(&db->db_holds) == 0) {
1792 /* The dbuf is referenced */
1794 if (db->db_last_dirty != NULL) {
1795 dbuf_dirty_record_t *dr = db->db_last_dirty;
1797 if (dr->dr_txg == txg) {
1799 * This buffer is "in-use", re-adjust the file
1800 * size to reflect that this buffer may
1801 * contain new data when we sync.
1803 if (db->db_blkid != DMU_SPILL_BLKID &&
1804 db->db_blkid > dn->dn_maxblkid)
1805 dn->dn_maxblkid = db->db_blkid;
1806 dbuf_unoverride(dr);
1809 * This dbuf is not dirty in the open context.
1810 * Either uncache it (if its not referenced in
1811 * the open context) or reset its contents to
1814 dbuf_fix_old_data(db, txg);
1817 /* clear the contents if its cached */
1818 if (db->db_state == DB_CACHED) {
1819 ASSERT(db->db.db_data != NULL);
1820 arc_release(db->db_buf, db);
1821 rw_enter(&db->db_rwlock, RW_WRITER);
1822 bzero(db->db.db_data, db->db.db_size);
1823 rw_exit(&db->db_rwlock);
1824 arc_buf_freeze(db->db_buf);
1827 mutex_exit(&db->db_mtx);
1830 kmem_free(db_search, sizeof (dmu_buf_impl_t));
1831 mutex_exit(&dn->dn_dbufs_mtx);
1835 dbuf_new_size(dmu_buf_impl_t *db, int size, dmu_tx_t *tx)
1837 arc_buf_t *buf, *obuf;
1838 int osize = db->db.db_size;
1839 arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db);
1842 ASSERT(db->db_blkid != DMU_BONUS_BLKID);
1848 * XXX we should be doing a dbuf_read, checking the return
1849 * value and returning that up to our callers
1851 dmu_buf_will_dirty(&db->db, tx);
1853 /* create the data buffer for the new block */
1854 buf = arc_alloc_buf(dn->dn_objset->os_spa, db, type, size);
1856 /* copy old block data to the new block */
1858 bcopy(obuf->b_data, buf->b_data, MIN(osize, size));
1859 /* zero the remainder */
1861 bzero((uint8_t *)buf->b_data + osize, size - osize);
1863 mutex_enter(&db->db_mtx);
1864 dbuf_set_data(db, buf);
1865 arc_buf_destroy(obuf, db);
1866 db->db.db_size = size;
1868 if (db->db_level == 0) {
1869 db->db_last_dirty->dt.dl.dr_data = buf;
1871 ASSERT3U(db->db_last_dirty->dr_txg, ==, tx->tx_txg);
1872 ASSERT3U(db->db_last_dirty->dr_accounted, ==, osize);
1873 db->db_last_dirty->dr_accounted = size;
1874 mutex_exit(&db->db_mtx);
1876 dmu_objset_willuse_space(dn->dn_objset, size - osize, tx);
1881 dbuf_release_bp(dmu_buf_impl_t *db)
1883 objset_t *os __maybe_unused = db->db_objset;
1885 ASSERT(dsl_pool_sync_context(dmu_objset_pool(os)));
1886 ASSERT(arc_released(os->os_phys_buf) ||
1887 list_link_active(&os->os_dsl_dataset->ds_synced_link));
1888 ASSERT(db->db_parent == NULL || arc_released(db->db_parent->db_buf));
1890 (void) arc_release(db->db_buf, db);
1894 * We already have a dirty record for this TXG, and we are being
1898 dbuf_redirty(dbuf_dirty_record_t *dr)
1900 dmu_buf_impl_t *db = dr->dr_dbuf;
1902 ASSERT(MUTEX_HELD(&db->db_mtx));
1904 if (db->db_level == 0 && db->db_blkid != DMU_BONUS_BLKID) {
1906 * If this buffer has already been written out,
1907 * we now need to reset its state.
1909 dbuf_unoverride(dr);
1910 if (db->db.db_object != DMU_META_DNODE_OBJECT &&
1911 db->db_state != DB_NOFILL) {
1912 /* Already released on initial dirty, so just thaw. */
1913 ASSERT(arc_released(db->db_buf));
1914 arc_buf_thaw(db->db_buf);
1919 dbuf_dirty_record_t *
1920 dbuf_dirty(dmu_buf_impl_t *db, dmu_tx_t *tx)
1924 dbuf_dirty_record_t **drp, *dr;
1925 int txgoff = tx->tx_txg & TXG_MASK;
1926 boolean_t drop_struct_rwlock = B_FALSE;
1928 ASSERT(tx->tx_txg != 0);
1929 ASSERT(!zfs_refcount_is_zero(&db->db_holds));
1930 DMU_TX_DIRTY_BUF(tx, db);
1935 * Shouldn't dirty a regular buffer in syncing context. Private
1936 * objects may be dirtied in syncing context, but only if they
1937 * were already pre-dirtied in open context.
1940 if (dn->dn_objset->os_dsl_dataset != NULL) {
1941 rrw_enter(&dn->dn_objset->os_dsl_dataset->ds_bp_rwlock,
1944 ASSERT(!dmu_tx_is_syncing(tx) ||
1945 BP_IS_HOLE(dn->dn_objset->os_rootbp) ||
1946 DMU_OBJECT_IS_SPECIAL(dn->dn_object) ||
1947 dn->dn_objset->os_dsl_dataset == NULL);
1948 if (dn->dn_objset->os_dsl_dataset != NULL)
1949 rrw_exit(&dn->dn_objset->os_dsl_dataset->ds_bp_rwlock, FTAG);
1952 * We make this assert for private objects as well, but after we
1953 * check if we're already dirty. They are allowed to re-dirty
1954 * in syncing context.
1956 ASSERT(dn->dn_object == DMU_META_DNODE_OBJECT ||
1957 dn->dn_dirtyctx == DN_UNDIRTIED || dn->dn_dirtyctx ==
1958 (dmu_tx_is_syncing(tx) ? DN_DIRTY_SYNC : DN_DIRTY_OPEN));
1960 mutex_enter(&db->db_mtx);
1962 * XXX make this true for indirects too? The problem is that
1963 * transactions created with dmu_tx_create_assigned() from
1964 * syncing context don't bother holding ahead.
1966 ASSERT(db->db_level != 0 ||
1967 db->db_state == DB_CACHED || db->db_state == DB_FILL ||
1968 db->db_state == DB_NOFILL);
1970 mutex_enter(&dn->dn_mtx);
1972 * Don't set dirtyctx to SYNC if we're just modifying this as we
1973 * initialize the objset.
1975 if (dn->dn_dirtyctx == DN_UNDIRTIED) {
1976 if (dn->dn_objset->os_dsl_dataset != NULL) {
1977 rrw_enter(&dn->dn_objset->os_dsl_dataset->ds_bp_rwlock,
1980 if (!BP_IS_HOLE(dn->dn_objset->os_rootbp)) {
1981 dn->dn_dirtyctx = (dmu_tx_is_syncing(tx) ?
1982 DN_DIRTY_SYNC : DN_DIRTY_OPEN);
1983 ASSERT(dn->dn_dirtyctx_firstset == NULL);
1984 dn->dn_dirtyctx_firstset = kmem_alloc(1, KM_SLEEP);
1986 if (dn->dn_objset->os_dsl_dataset != NULL) {
1987 rrw_exit(&dn->dn_objset->os_dsl_dataset->ds_bp_rwlock,
1992 if (tx->tx_txg > dn->dn_dirty_txg)
1993 dn->dn_dirty_txg = tx->tx_txg;
1994 mutex_exit(&dn->dn_mtx);
1996 if (db->db_blkid == DMU_SPILL_BLKID)
1997 dn->dn_have_spill = B_TRUE;
2000 * If this buffer is already dirty, we're done.
2002 drp = &db->db_last_dirty;
2003 ASSERT(*drp == NULL || (*drp)->dr_txg <= tx->tx_txg ||
2004 db->db.db_object == DMU_META_DNODE_OBJECT);
2005 while ((dr = *drp) != NULL && dr->dr_txg > tx->tx_txg)
2007 if (dr && dr->dr_txg == tx->tx_txg) {
2011 mutex_exit(&db->db_mtx);
2016 * Only valid if not already dirty.
2018 ASSERT(dn->dn_object == 0 ||
2019 dn->dn_dirtyctx == DN_UNDIRTIED || dn->dn_dirtyctx ==
2020 (dmu_tx_is_syncing(tx) ? DN_DIRTY_SYNC : DN_DIRTY_OPEN));
2022 ASSERT3U(dn->dn_nlevels, >, db->db_level);
2025 * We should only be dirtying in syncing context if it's the
2026 * mos or we're initializing the os or it's a special object.
2027 * However, we are allowed to dirty in syncing context provided
2028 * we already dirtied it in open context. Hence we must make
2029 * this assertion only if we're not already dirty.
2032 VERIFY3U(tx->tx_txg, <=, spa_final_dirty_txg(os->os_spa));
2034 if (dn->dn_objset->os_dsl_dataset != NULL)
2035 rrw_enter(&os->os_dsl_dataset->ds_bp_rwlock, RW_READER, FTAG);
2036 ASSERT(!dmu_tx_is_syncing(tx) || DMU_OBJECT_IS_SPECIAL(dn->dn_object) ||
2037 os->os_dsl_dataset == NULL || BP_IS_HOLE(os->os_rootbp));
2038 if (dn->dn_objset->os_dsl_dataset != NULL)
2039 rrw_exit(&os->os_dsl_dataset->ds_bp_rwlock, FTAG);
2041 ASSERT(db->db.db_size != 0);
2043 dprintf_dbuf(db, "size=%llx\n", (u_longlong_t)db->db.db_size);
2045 if (db->db_blkid != DMU_BONUS_BLKID) {
2046 dmu_objset_willuse_space(os, db->db.db_size, tx);
2050 * If this buffer is dirty in an old transaction group we need
2051 * to make a copy of it so that the changes we make in this
2052 * transaction group won't leak out when we sync the older txg.
2054 dr = kmem_zalloc(sizeof (dbuf_dirty_record_t), KM_SLEEP);
2055 list_link_init(&dr->dr_dirty_node);
2056 if (db->db_level == 0) {
2057 void *data_old = db->db_buf;
2059 if (db->db_state != DB_NOFILL) {
2060 if (db->db_blkid == DMU_BONUS_BLKID) {
2061 dbuf_fix_old_data(db, tx->tx_txg);
2062 data_old = db->db.db_data;
2063 } else if (db->db.db_object != DMU_META_DNODE_OBJECT) {
2065 * Release the data buffer from the cache so
2066 * that we can modify it without impacting
2067 * possible other users of this cached data
2068 * block. Note that indirect blocks and
2069 * private objects are not released until the
2070 * syncing state (since they are only modified
2073 arc_release(db->db_buf, db);
2074 dbuf_fix_old_data(db, tx->tx_txg);
2075 data_old = db->db_buf;
2077 ASSERT(data_old != NULL);
2079 dr->dt.dl.dr_data = data_old;
2081 mutex_init(&dr->dt.di.dr_mtx, NULL, MUTEX_NOLOCKDEP, NULL);
2082 list_create(&dr->dt.di.dr_children,
2083 sizeof (dbuf_dirty_record_t),
2084 offsetof(dbuf_dirty_record_t, dr_dirty_node));
2086 if (db->db_blkid != DMU_BONUS_BLKID)
2087 dr->dr_accounted = db->db.db_size;
2089 dr->dr_txg = tx->tx_txg;
2094 * We could have been freed_in_flight between the dbuf_noread
2095 * and dbuf_dirty. We win, as though the dbuf_noread() had
2096 * happened after the free.
2098 if (db->db_level == 0 && db->db_blkid != DMU_BONUS_BLKID &&
2099 db->db_blkid != DMU_SPILL_BLKID) {
2100 mutex_enter(&dn->dn_mtx);
2101 if (dn->dn_free_ranges[txgoff] != NULL) {
2102 range_tree_clear(dn->dn_free_ranges[txgoff],
2105 mutex_exit(&dn->dn_mtx);
2106 db->db_freed_in_flight = FALSE;
2110 * This buffer is now part of this txg
2112 dbuf_add_ref(db, (void *)(uintptr_t)tx->tx_txg);
2113 db->db_dirtycnt += 1;
2114 ASSERT3U(db->db_dirtycnt, <=, 3);
2116 mutex_exit(&db->db_mtx);
2118 if (db->db_blkid == DMU_BONUS_BLKID ||
2119 db->db_blkid == DMU_SPILL_BLKID) {
2120 mutex_enter(&dn->dn_mtx);
2121 ASSERT(!list_link_active(&dr->dr_dirty_node));
2122 list_insert_tail(&dn->dn_dirty_records[txgoff], dr);
2123 mutex_exit(&dn->dn_mtx);
2124 dnode_setdirty(dn, tx);
2129 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) {
2130 rw_enter(&dn->dn_struct_rwlock, RW_READER);
2131 drop_struct_rwlock = B_TRUE;
2135 * If we are overwriting a dedup BP, then unless it is snapshotted,
2136 * when we get to syncing context we will need to decrement its
2137 * refcount in the DDT. Prefetch the relevant DDT block so that
2138 * syncing context won't have to wait for the i/o.
2140 if (db->db_blkptr != NULL) {
2141 db_lock_type_t dblt = dmu_buf_lock_parent(db, RW_READER, FTAG);
2142 ddt_prefetch(os->os_spa, db->db_blkptr);
2143 dmu_buf_unlock_parent(db, dblt, FTAG);
2147 * We need to hold the dn_struct_rwlock to make this assertion,
2148 * because it protects dn_phys / dn_next_nlevels from changing.
2150 ASSERT((dn->dn_phys->dn_nlevels == 0 && db->db_level == 0) ||
2151 dn->dn_phys->dn_nlevels > db->db_level ||
2152 dn->dn_next_nlevels[txgoff] > db->db_level ||
2153 dn->dn_next_nlevels[(tx->tx_txg-1) & TXG_MASK] > db->db_level ||
2154 dn->dn_next_nlevels[(tx->tx_txg-2) & TXG_MASK] > db->db_level);
2157 if (db->db_level == 0) {
2158 ASSERT(!db->db_objset->os_raw_receive ||
2159 dn->dn_maxblkid >= db->db_blkid);
2160 dnode_new_blkid(dn, db->db_blkid, tx,
2161 drop_struct_rwlock, B_FALSE);
2162 ASSERT(dn->dn_maxblkid >= db->db_blkid);
2165 if (db->db_level+1 < dn->dn_nlevels) {
2166 dmu_buf_impl_t *parent = db->db_parent;
2167 dbuf_dirty_record_t *di;
2168 int parent_held = FALSE;
2170 if (db->db_parent == NULL || db->db_parent == dn->dn_dbuf) {
2171 int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
2172 parent = dbuf_hold_level(dn, db->db_level + 1,
2173 db->db_blkid >> epbs, FTAG);
2174 ASSERT(parent != NULL);
2177 if (drop_struct_rwlock)
2178 rw_exit(&dn->dn_struct_rwlock);
2179 ASSERT3U(db->db_level + 1, ==, parent->db_level);
2180 di = dbuf_dirty(parent, tx);
2182 dbuf_rele(parent, FTAG);
2184 mutex_enter(&db->db_mtx);
2186 * Since we've dropped the mutex, it's possible that
2187 * dbuf_undirty() might have changed this out from under us.
2189 if (db->db_last_dirty == dr ||
2190 dn->dn_object == DMU_META_DNODE_OBJECT) {
2191 mutex_enter(&di->dt.di.dr_mtx);
2192 ASSERT3U(di->dr_txg, ==, tx->tx_txg);
2193 ASSERT(!list_link_active(&dr->dr_dirty_node));
2194 list_insert_tail(&di->dt.di.dr_children, dr);
2195 mutex_exit(&di->dt.di.dr_mtx);
2198 mutex_exit(&db->db_mtx);
2200 ASSERT(db->db_level + 1 == dn->dn_nlevels);
2201 ASSERT(db->db_blkid < dn->dn_nblkptr);
2202 ASSERT(db->db_parent == NULL || db->db_parent == dn->dn_dbuf);
2203 mutex_enter(&dn->dn_mtx);
2204 ASSERT(!list_link_active(&dr->dr_dirty_node));
2205 list_insert_tail(&dn->dn_dirty_records[txgoff], dr);
2206 mutex_exit(&dn->dn_mtx);
2207 if (drop_struct_rwlock)
2208 rw_exit(&dn->dn_struct_rwlock);
2211 dnode_setdirty(dn, tx);
2217 * Undirty a buffer in the transaction group referenced by the given
2218 * transaction. Return whether this evicted the dbuf.
2221 dbuf_undirty(dmu_buf_impl_t *db, dmu_tx_t *tx)
2224 uint64_t txg = tx->tx_txg;
2225 dbuf_dirty_record_t *dr, **drp;
2230 * Due to our use of dn_nlevels below, this can only be called
2231 * in open context, unless we are operating on the MOS.
2232 * From syncing context, dn_nlevels may be different from the
2233 * dn_nlevels used when dbuf was dirtied.
2235 ASSERT(db->db_objset ==
2236 dmu_objset_pool(db->db_objset)->dp_meta_objset ||
2237 txg != spa_syncing_txg(dmu_objset_spa(db->db_objset)));
2238 ASSERT(db->db_blkid != DMU_BONUS_BLKID);
2239 ASSERT0(db->db_level);
2240 ASSERT(MUTEX_HELD(&db->db_mtx));
2243 * If this buffer is not dirty, we're done.
2245 for (drp = &db->db_last_dirty; (dr = *drp) != NULL; drp = &dr->dr_next)
2246 if (dr->dr_txg <= txg)
2248 if (dr == NULL || dr->dr_txg < txg)
2250 ASSERT(dr->dr_txg == txg);
2251 ASSERT(dr->dr_dbuf == db);
2256 dprintf_dbuf(db, "size=%llx\n", (u_longlong_t)db->db.db_size);
2258 ASSERT(db->db.db_size != 0);
2260 dsl_pool_undirty_space(dmu_objset_pool(dn->dn_objset),
2261 dr->dr_accounted, txg);
2266 * Note that there are three places in dbuf_dirty()
2267 * where this dirty record may be put on a list.
2268 * Make sure to do a list_remove corresponding to
2269 * every one of those list_insert calls.
2271 if (dr->dr_parent) {
2272 mutex_enter(&dr->dr_parent->dt.di.dr_mtx);
2273 list_remove(&dr->dr_parent->dt.di.dr_children, dr);
2274 mutex_exit(&dr->dr_parent->dt.di.dr_mtx);
2275 } else if (db->db_blkid == DMU_SPILL_BLKID ||
2276 db->db_level + 1 == dn->dn_nlevels) {
2277 ASSERT(db->db_blkptr == NULL || db->db_parent == dn->dn_dbuf);
2278 mutex_enter(&dn->dn_mtx);
2279 list_remove(&dn->dn_dirty_records[txg & TXG_MASK], dr);
2280 mutex_exit(&dn->dn_mtx);
2284 if (db->db_state != DB_NOFILL) {
2285 dbuf_unoverride(dr);
2287 ASSERT(db->db_buf != NULL);
2288 ASSERT(dr->dt.dl.dr_data != NULL);
2289 if (dr->dt.dl.dr_data != db->db_buf)
2290 arc_buf_destroy(dr->dt.dl.dr_data, db);
2293 kmem_free(dr, sizeof (dbuf_dirty_record_t));
2295 ASSERT(db->db_dirtycnt > 0);
2296 db->db_dirtycnt -= 1;
2298 if (zfs_refcount_remove(&db->db_holds, (void *)(uintptr_t)txg) == 0) {
2299 ASSERT(db->db_state == DB_NOFILL || arc_released(db->db_buf));
2308 dmu_buf_will_dirty_impl(dmu_buf_t *db_fake, int flags, dmu_tx_t *tx)
2310 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
2312 ASSERT(tx->tx_txg != 0);
2313 ASSERT(!zfs_refcount_is_zero(&db->db_holds));
2316 * Quick check for dirtiness. For already dirty blocks, this
2317 * reduces runtime of this function by >90%, and overall performance
2318 * by 50% for some workloads (e.g. file deletion with indirect blocks
2321 mutex_enter(&db->db_mtx);
2323 dbuf_dirty_record_t *dr;
2324 for (dr = db->db_last_dirty;
2325 dr != NULL && dr->dr_txg >= tx->tx_txg; dr = dr->dr_next) {
2327 * It's possible that it is already dirty but not cached,
2328 * because there are some calls to dbuf_dirty() that don't
2329 * go through dmu_buf_will_dirty().
2331 if (dr->dr_txg == tx->tx_txg && db->db_state == DB_CACHED) {
2332 /* This dbuf is already dirty and cached. */
2334 mutex_exit(&db->db_mtx);
2338 mutex_exit(&db->db_mtx);
2341 if (RW_WRITE_HELD(&DB_DNODE(db)->dn_struct_rwlock))
2342 flags |= DB_RF_HAVESTRUCT;
2344 (void) dbuf_read(db, NULL, flags);
2345 (void) dbuf_dirty(db, tx);
2349 dmu_buf_will_dirty(dmu_buf_t *db_fake, dmu_tx_t *tx)
2351 dmu_buf_will_dirty_impl(db_fake,
2352 DB_RF_MUST_SUCCEED | DB_RF_NOPREFETCH, tx);
2356 dmu_buf_is_dirty(dmu_buf_t *db_fake, dmu_tx_t *tx)
2358 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
2360 mutex_enter(&db->db_mtx);
2361 for (dbuf_dirty_record_t *dr = db->db_last_dirty;
2362 dr != NULL && dr->dr_txg >= tx->tx_txg; dr = dr->dr_next) {
2363 if (dr->dr_txg == tx->tx_txg) {
2364 mutex_exit(&db->db_mtx);
2368 mutex_exit(&db->db_mtx);
2373 dmu_buf_will_not_fill(dmu_buf_t *db_fake, dmu_tx_t *tx)
2375 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
2377 db->db_state = DB_NOFILL;
2379 dmu_buf_will_fill(db_fake, tx);
2383 dmu_buf_will_fill(dmu_buf_t *db_fake, dmu_tx_t *tx)
2385 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
2387 ASSERT(db->db_blkid != DMU_BONUS_BLKID);
2388 ASSERT(tx->tx_txg != 0);
2389 ASSERT(db->db_level == 0);
2390 ASSERT(!zfs_refcount_is_zero(&db->db_holds));
2392 ASSERT(db->db.db_object != DMU_META_DNODE_OBJECT ||
2393 dmu_tx_private_ok(tx));
2396 (void) dbuf_dirty(db, tx);
2400 * This function is effectively the same as dmu_buf_will_dirty(), but
2401 * indicates the caller expects raw encrypted data in the db, and provides
2402 * the crypt params (byteorder, salt, iv, mac) which should be stored in the
2403 * blkptr_t when this dbuf is written. This is only used for blocks of
2404 * dnodes, during raw receive.
2407 dmu_buf_set_crypt_params(dmu_buf_t *db_fake, boolean_t byteorder,
2408 const uint8_t *salt, const uint8_t *iv, const uint8_t *mac, dmu_tx_t *tx)
2410 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
2411 dbuf_dirty_record_t *dr;
2414 * dr_has_raw_params is only processed for blocks of dnodes
2415 * (see dbuf_sync_dnode_leaf_crypt()).
2417 ASSERT3U(db->db.db_object, ==, DMU_META_DNODE_OBJECT);
2418 ASSERT3U(db->db_level, ==, 0);
2419 ASSERT(db->db_objset->os_raw_receive);
2421 dmu_buf_will_dirty_impl(db_fake,
2422 DB_RF_MUST_SUCCEED | DB_RF_NOPREFETCH | DB_RF_NO_DECRYPT, tx);
2424 dr = db->db_last_dirty;
2425 while (dr != NULL && dr->dr_txg > tx->tx_txg)
2428 ASSERT3P(dr, !=, NULL);
2429 ASSERT3U(dr->dr_txg, ==, tx->tx_txg);
2431 dr->dt.dl.dr_has_raw_params = B_TRUE;
2432 dr->dt.dl.dr_byteorder = byteorder;
2433 bcopy(salt, dr->dt.dl.dr_salt, ZIO_DATA_SALT_LEN);
2434 bcopy(iv, dr->dt.dl.dr_iv, ZIO_DATA_IV_LEN);
2435 bcopy(mac, dr->dt.dl.dr_mac, ZIO_DATA_MAC_LEN);
2439 dbuf_override_impl(dmu_buf_impl_t *db, const blkptr_t *bp, dmu_tx_t *tx)
2441 struct dirty_leaf *dl;
2443 ASSERT3U(db->db_last_dirty->dr_txg, ==, tx->tx_txg);
2444 dl = &db->db_last_dirty->dt.dl;
2445 dl->dr_overridden_by = *bp;
2446 dl->dr_override_state = DR_OVERRIDDEN;
2447 dl->dr_overridden_by.blk_birth = db->db_last_dirty->dr_txg;
2452 dmu_buf_fill_done(dmu_buf_t *dbuf, dmu_tx_t *tx)
2454 dmu_buf_impl_t *db = (dmu_buf_impl_t *)dbuf;
2455 mutex_enter(&db->db_mtx);
2458 if (db->db_state == DB_FILL) {
2459 if (db->db_level == 0 && db->db_freed_in_flight) {
2460 ASSERT(db->db_blkid != DMU_BONUS_BLKID);
2461 /* we were freed while filling */
2462 /* XXX dbuf_undirty? */
2463 bzero(db->db.db_data, db->db.db_size);
2464 db->db_freed_in_flight = FALSE;
2466 db->db_state = DB_CACHED;
2467 cv_broadcast(&db->db_changed);
2469 mutex_exit(&db->db_mtx);
2473 dmu_buf_write_embedded(dmu_buf_t *dbuf, void *data,
2474 bp_embedded_type_t etype, enum zio_compress comp,
2475 int uncompressed_size, int compressed_size, int byteorder,
2478 dmu_buf_impl_t *db = (dmu_buf_impl_t *)dbuf;
2479 struct dirty_leaf *dl;
2480 dmu_object_type_t type;
2482 if (etype == BP_EMBEDDED_TYPE_DATA) {
2483 ASSERT(spa_feature_is_active(dmu_objset_spa(db->db_objset),
2484 SPA_FEATURE_EMBEDDED_DATA));
2488 type = DB_DNODE(db)->dn_type;
2491 ASSERT0(db->db_level);
2492 ASSERT(db->db_blkid != DMU_BONUS_BLKID);
2494 dmu_buf_will_not_fill(dbuf, tx);
2496 ASSERT3U(db->db_last_dirty->dr_txg, ==, tx->tx_txg);
2497 dl = &db->db_last_dirty->dt.dl;
2498 encode_embedded_bp_compressed(&dl->dr_overridden_by,
2499 data, comp, uncompressed_size, compressed_size);
2500 BPE_SET_ETYPE(&dl->dr_overridden_by, etype);
2501 BP_SET_TYPE(&dl->dr_overridden_by, type);
2502 BP_SET_LEVEL(&dl->dr_overridden_by, 0);
2503 BP_SET_BYTEORDER(&dl->dr_overridden_by, byteorder);
2505 dl->dr_override_state = DR_OVERRIDDEN;
2506 dl->dr_overridden_by.blk_birth = db->db_last_dirty->dr_txg;
2510 dmu_buf_redact(dmu_buf_t *dbuf, dmu_tx_t *tx)
2512 dmu_buf_impl_t *db = (dmu_buf_impl_t *)dbuf;
2513 dmu_object_type_t type;
2514 ASSERT(dsl_dataset_feature_is_active(db->db_objset->os_dsl_dataset,
2515 SPA_FEATURE_REDACTED_DATASETS));
2518 type = DB_DNODE(db)->dn_type;
2521 ASSERT0(db->db_level);
2522 dmu_buf_will_not_fill(dbuf, tx);
2524 blkptr_t bp = { { { {0} } } };
2525 BP_SET_TYPE(&bp, type);
2526 BP_SET_LEVEL(&bp, 0);
2527 BP_SET_BIRTH(&bp, tx->tx_txg, 0);
2528 BP_SET_REDACTED(&bp);
2529 BPE_SET_LSIZE(&bp, dbuf->db_size);
2531 dbuf_override_impl(db, &bp, tx);
2535 * Directly assign a provided arc buf to a given dbuf if it's not referenced
2536 * by anybody except our caller. Otherwise copy arcbuf's contents to dbuf.
2539 dbuf_assign_arcbuf(dmu_buf_impl_t *db, arc_buf_t *buf, dmu_tx_t *tx)
2541 ASSERT(!zfs_refcount_is_zero(&db->db_holds));
2542 ASSERT(db->db_blkid != DMU_BONUS_BLKID);
2543 ASSERT(db->db_level == 0);
2544 ASSERT3U(dbuf_is_metadata(db), ==, arc_is_metadata(buf));
2545 ASSERT(buf != NULL);
2546 ASSERT3U(arc_buf_lsize(buf), ==, db->db.db_size);
2547 ASSERT(tx->tx_txg != 0);
2549 arc_return_buf(buf, db);
2550 ASSERT(arc_released(buf));
2552 mutex_enter(&db->db_mtx);
2554 while (db->db_state == DB_READ || db->db_state == DB_FILL)
2555 cv_wait(&db->db_changed, &db->db_mtx);
2557 ASSERT(db->db_state == DB_CACHED || db->db_state == DB_UNCACHED);
2559 if (db->db_state == DB_CACHED &&
2560 zfs_refcount_count(&db->db_holds) - 1 > db->db_dirtycnt) {
2562 * In practice, we will never have a case where we have an
2563 * encrypted arc buffer while additional holds exist on the
2564 * dbuf. We don't handle this here so we simply assert that
2567 ASSERT(!arc_is_encrypted(buf));
2568 mutex_exit(&db->db_mtx);
2569 (void) dbuf_dirty(db, tx);
2570 bcopy(buf->b_data, db->db.db_data, db->db.db_size);
2571 arc_buf_destroy(buf, db);
2572 xuio_stat_wbuf_copied();
2576 xuio_stat_wbuf_nocopy();
2577 if (db->db_state == DB_CACHED) {
2578 dbuf_dirty_record_t *dr = db->db_last_dirty;
2580 ASSERT(db->db_buf != NULL);
2581 if (dr != NULL && dr->dr_txg == tx->tx_txg) {
2582 ASSERT(dr->dt.dl.dr_data == db->db_buf);
2584 if (!arc_released(db->db_buf)) {
2585 ASSERT(dr->dt.dl.dr_override_state ==
2587 arc_release(db->db_buf, db);
2589 dr->dt.dl.dr_data = buf;
2590 arc_buf_destroy(db->db_buf, db);
2591 } else if (dr == NULL || dr->dt.dl.dr_data != db->db_buf) {
2592 arc_release(db->db_buf, db);
2593 arc_buf_destroy(db->db_buf, db);
2597 ASSERT(db->db_buf == NULL);
2598 dbuf_set_data(db, buf);
2599 db->db_state = DB_FILL;
2600 mutex_exit(&db->db_mtx);
2601 (void) dbuf_dirty(db, tx);
2602 dmu_buf_fill_done(&db->db, tx);
2606 dbuf_destroy(dmu_buf_impl_t *db)
2609 dmu_buf_impl_t *parent = db->db_parent;
2610 dmu_buf_impl_t *dndb;
2612 ASSERT(MUTEX_HELD(&db->db_mtx));
2613 ASSERT(zfs_refcount_is_zero(&db->db_holds));
2615 if (db->db_buf != NULL) {
2616 arc_buf_destroy(db->db_buf, db);
2620 if (db->db_blkid == DMU_BONUS_BLKID) {
2621 int slots = DB_DNODE(db)->dn_num_slots;
2622 int bonuslen = DN_SLOTS_TO_BONUSLEN(slots);
2623 if (db->db.db_data != NULL) {
2624 kmem_free(db->db.db_data, bonuslen);
2625 arc_space_return(bonuslen, ARC_SPACE_BONUS);
2626 db->db_state = DB_UNCACHED;
2630 dbuf_clear_data(db);
2632 if (multilist_link_active(&db->db_cache_link)) {
2633 ASSERT(db->db_caching_status == DB_DBUF_CACHE ||
2634 db->db_caching_status == DB_DBUF_METADATA_CACHE);
2636 multilist_remove(dbuf_caches[db->db_caching_status].cache, db);
2637 (void) zfs_refcount_remove_many(
2638 &dbuf_caches[db->db_caching_status].size,
2639 db->db.db_size, db);
2641 if (db->db_caching_status == DB_DBUF_METADATA_CACHE) {
2642 DBUF_STAT_BUMPDOWN(metadata_cache_count);
2644 DBUF_STAT_BUMPDOWN(cache_levels[db->db_level]);
2645 DBUF_STAT_BUMPDOWN(cache_count);
2646 DBUF_STAT_DECR(cache_levels_bytes[db->db_level],
2649 db->db_caching_status = DB_NO_CACHE;
2652 ASSERT(db->db_state == DB_UNCACHED || db->db_state == DB_NOFILL);
2653 ASSERT(db->db_data_pending == NULL);
2655 db->db_state = DB_EVICTING;
2656 db->db_blkptr = NULL;
2659 * Now that db_state is DB_EVICTING, nobody else can find this via
2660 * the hash table. We can now drop db_mtx, which allows us to
2661 * acquire the dn_dbufs_mtx.
2663 mutex_exit(&db->db_mtx);
2668 if (db->db_blkid != DMU_BONUS_BLKID) {
2669 boolean_t needlock = !MUTEX_HELD(&dn->dn_dbufs_mtx);
2671 mutex_enter_nested(&dn->dn_dbufs_mtx,
2673 avl_remove(&dn->dn_dbufs, db);
2674 atomic_dec_32(&dn->dn_dbufs_count);
2678 mutex_exit(&dn->dn_dbufs_mtx);
2680 * Decrementing the dbuf count means that the hold corresponding
2681 * to the removed dbuf is no longer discounted in dnode_move(),
2682 * so the dnode cannot be moved until after we release the hold.
2683 * The membar_producer() ensures visibility of the decremented
2684 * value in dnode_move(), since DB_DNODE_EXIT doesn't actually
2687 mutex_enter(&dn->dn_mtx);
2688 dnode_rele_and_unlock(dn, db, B_TRUE);
2689 db->db_dnode_handle = NULL;
2691 dbuf_hash_remove(db);
2696 ASSERT(zfs_refcount_is_zero(&db->db_holds));
2698 db->db_parent = NULL;
2700 ASSERT(db->db_buf == NULL);
2701 ASSERT(db->db.db_data == NULL);
2702 ASSERT(db->db_hash_next == NULL);
2703 ASSERT(db->db_blkptr == NULL);
2704 ASSERT(db->db_data_pending == NULL);
2705 ASSERT3U(db->db_caching_status, ==, DB_NO_CACHE);
2706 ASSERT(!multilist_link_active(&db->db_cache_link));
2708 kmem_cache_free(dbuf_kmem_cache, db);
2709 arc_space_return(sizeof (dmu_buf_impl_t), ARC_SPACE_DBUF);
2712 * If this dbuf is referenced from an indirect dbuf,
2713 * decrement the ref count on the indirect dbuf.
2715 if (parent && parent != dndb) {
2716 mutex_enter(&parent->db_mtx);
2717 dbuf_rele_and_unlock(parent, db, B_TRUE);
2722 * Note: While bpp will always be updated if the function returns success,
2723 * parentp will not be updated if the dnode does not have dn_dbuf filled in;
2724 * this happens when the dnode is the meta-dnode, or {user|group|project}used
2727 __attribute__((always_inline))
2729 dbuf_findbp(dnode_t *dn, int level, uint64_t blkid, int fail_sparse,
2730 dmu_buf_impl_t **parentp, blkptr_t **bpp)
2735 ASSERT(blkid != DMU_BONUS_BLKID);
2737 if (blkid == DMU_SPILL_BLKID) {
2738 mutex_enter(&dn->dn_mtx);
2739 if (dn->dn_have_spill &&
2740 (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR))
2741 *bpp = DN_SPILL_BLKPTR(dn->dn_phys);
2744 dbuf_add_ref(dn->dn_dbuf, NULL);
2745 *parentp = dn->dn_dbuf;
2746 mutex_exit(&dn->dn_mtx);
2751 (dn->dn_phys->dn_nlevels == 0) ? 1 : dn->dn_phys->dn_nlevels;
2752 int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
2754 ASSERT3U(level * epbs, <, 64);
2755 ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock));
2757 * This assertion shouldn't trip as long as the max indirect block size
2758 * is less than 1M. The reason for this is that up to that point,
2759 * the number of levels required to address an entire object with blocks
2760 * of size SPA_MINBLOCKSIZE satisfies nlevels * epbs + 1 <= 64. In
2761 * other words, if N * epbs + 1 > 64, then if (N-1) * epbs + 1 > 55
2762 * (i.e. we can address the entire object), objects will all use at most
2763 * N-1 levels and the assertion won't overflow. However, once epbs is
2764 * 13, 4 * 13 + 1 = 53, but 5 * 13 + 1 = 66. Then, 4 levels will not be
2765 * enough to address an entire object, so objects will have 5 levels,
2766 * but then this assertion will overflow.
2768 * All this is to say that if we ever increase DN_MAX_INDBLKSHIFT, we
2769 * need to redo this logic to handle overflows.
2771 ASSERT(level >= nlevels ||
2772 ((nlevels - level - 1) * epbs) +
2773 highbit64(dn->dn_phys->dn_nblkptr) <= 64);
2774 if (level >= nlevels ||
2775 blkid >= ((uint64_t)dn->dn_phys->dn_nblkptr <<
2776 ((nlevels - level - 1) * epbs)) ||
2778 blkid > (dn->dn_phys->dn_maxblkid >> (level * epbs)))) {
2779 /* the buffer has no parent yet */
2780 return (SET_ERROR(ENOENT));
2781 } else if (level < nlevels-1) {
2782 /* this block is referenced from an indirect block */
2785 err = dbuf_hold_impl(dn, level + 1,
2786 blkid >> epbs, fail_sparse, FALSE, NULL, parentp);
2790 err = dbuf_read(*parentp, NULL,
2791 (DB_RF_HAVESTRUCT | DB_RF_NOPREFETCH | DB_RF_CANFAIL));
2793 dbuf_rele(*parentp, NULL);
2797 rw_enter(&(*parentp)->db_rwlock, RW_READER);
2798 *bpp = ((blkptr_t *)(*parentp)->db.db_data) +
2799 (blkid & ((1ULL << epbs) - 1));
2800 if (blkid > (dn->dn_phys->dn_maxblkid >> (level * epbs)))
2801 ASSERT(BP_IS_HOLE(*bpp));
2802 rw_exit(&(*parentp)->db_rwlock);
2805 /* the block is referenced from the dnode */
2806 ASSERT3U(level, ==, nlevels-1);
2807 ASSERT(dn->dn_phys->dn_nblkptr == 0 ||
2808 blkid < dn->dn_phys->dn_nblkptr);
2810 dbuf_add_ref(dn->dn_dbuf, NULL);
2811 *parentp = dn->dn_dbuf;
2813 *bpp = &dn->dn_phys->dn_blkptr[blkid];
2818 static dmu_buf_impl_t *
2819 dbuf_create(dnode_t *dn, uint8_t level, uint64_t blkid,
2820 dmu_buf_impl_t *parent, blkptr_t *blkptr)
2822 objset_t *os = dn->dn_objset;
2823 dmu_buf_impl_t *db, *odb;
2825 ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock));
2826 ASSERT(dn->dn_type != DMU_OT_NONE);
2828 db = kmem_cache_alloc(dbuf_kmem_cache, KM_SLEEP);
2831 db->db.db_object = dn->dn_object;
2832 db->db_level = level;
2833 db->db_blkid = blkid;
2834 db->db_last_dirty = NULL;
2835 db->db_dirtycnt = 0;
2836 db->db_dnode_handle = dn->dn_handle;
2837 db->db_parent = parent;
2838 db->db_blkptr = blkptr;
2841 db->db_user_immediate_evict = FALSE;
2842 db->db_freed_in_flight = FALSE;
2843 db->db_pending_evict = FALSE;
2845 if (blkid == DMU_BONUS_BLKID) {
2846 ASSERT3P(parent, ==, dn->dn_dbuf);
2847 db->db.db_size = DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots) -
2848 (dn->dn_nblkptr-1) * sizeof (blkptr_t);
2849 ASSERT3U(db->db.db_size, >=, dn->dn_bonuslen);
2850 db->db.db_offset = DMU_BONUS_BLKID;
2851 db->db_state = DB_UNCACHED;
2852 db->db_caching_status = DB_NO_CACHE;
2853 /* the bonus dbuf is not placed in the hash table */
2854 arc_space_consume(sizeof (dmu_buf_impl_t), ARC_SPACE_DBUF);
2856 } else if (blkid == DMU_SPILL_BLKID) {
2857 db->db.db_size = (blkptr != NULL) ?
2858 BP_GET_LSIZE(blkptr) : SPA_MINBLOCKSIZE;
2859 db->db.db_offset = 0;
2862 db->db_level ? 1 << dn->dn_indblkshift : dn->dn_datablksz;
2863 db->db.db_size = blocksize;
2864 db->db.db_offset = db->db_blkid * blocksize;
2868 * Hold the dn_dbufs_mtx while we get the new dbuf
2869 * in the hash table *and* added to the dbufs list.
2870 * This prevents a possible deadlock with someone
2871 * trying to look up this dbuf before it's added to the
2874 mutex_enter(&dn->dn_dbufs_mtx);
2875 db->db_state = DB_EVICTING;
2876 if ((odb = dbuf_hash_insert(db)) != NULL) {
2877 /* someone else inserted it first */
2878 kmem_cache_free(dbuf_kmem_cache, db);
2879 mutex_exit(&dn->dn_dbufs_mtx);
2880 DBUF_STAT_BUMP(hash_insert_race);
2883 avl_add(&dn->dn_dbufs, db);
2885 db->db_state = DB_UNCACHED;
2886 db->db_caching_status = DB_NO_CACHE;
2887 mutex_exit(&dn->dn_dbufs_mtx);
2888 arc_space_consume(sizeof (dmu_buf_impl_t), ARC_SPACE_DBUF);
2890 if (parent && parent != dn->dn_dbuf)
2891 dbuf_add_ref(parent, db);
2893 ASSERT(dn->dn_object == DMU_META_DNODE_OBJECT ||
2894 zfs_refcount_count(&dn->dn_holds) > 0);
2895 (void) zfs_refcount_add(&dn->dn_holds, db);
2896 atomic_inc_32(&dn->dn_dbufs_count);
2898 dprintf_dbuf(db, "db=%p\n", db);
2904 * This function returns a block pointer and information about the object,
2905 * given a dnode and a block. This is a publicly accessible version of
2906 * dbuf_findbp that only returns some information, rather than the
2907 * dbuf. Note that the dnode passed in must be held, and the dn_struct_rwlock
2908 * should be locked as (at least) a reader.
2911 dbuf_dnode_findbp(dnode_t *dn, uint64_t level, uint64_t blkid,
2912 blkptr_t *bp, uint16_t *datablkszsec, uint8_t *indblkshift)
2914 dmu_buf_impl_t *dbp = NULL;
2917 ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock));
2919 err = dbuf_findbp(dn, level, blkid, B_FALSE, &dbp, &bp2);
2923 dbuf_rele(dbp, NULL);
2924 if (datablkszsec != NULL)
2925 *datablkszsec = dn->dn_phys->dn_datablkszsec;
2926 if (indblkshift != NULL)
2927 *indblkshift = dn->dn_phys->dn_indblkshift;
2933 typedef struct dbuf_prefetch_arg {
2934 spa_t *dpa_spa; /* The spa to issue the prefetch in. */
2935 zbookmark_phys_t dpa_zb; /* The target block to prefetch. */
2936 int dpa_epbs; /* Entries (blkptr_t's) Per Block Shift. */
2937 int dpa_curlevel; /* The current level that we're reading */
2938 dnode_t *dpa_dnode; /* The dnode associated with the prefetch */
2939 zio_priority_t dpa_prio; /* The priority I/Os should be issued at. */
2940 zio_t *dpa_zio; /* The parent zio_t for all prefetches. */
2941 arc_flags_t dpa_aflags; /* Flags to pass to the final prefetch. */
2942 } dbuf_prefetch_arg_t;
2945 * Actually issue the prefetch read for the block given.
2948 dbuf_issue_final_prefetch(dbuf_prefetch_arg_t *dpa, blkptr_t *bp)
2950 ASSERT(!BP_IS_REDACTED(bp) ||
2951 dsl_dataset_feature_is_active(
2952 dpa->dpa_dnode->dn_objset->os_dsl_dataset,
2953 SPA_FEATURE_REDACTED_DATASETS));
2955 if (BP_IS_HOLE(bp) || BP_IS_EMBEDDED(bp) || BP_IS_REDACTED(bp))
2958 int zio_flags = ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE;
2959 arc_flags_t aflags =
2960 dpa->dpa_aflags | ARC_FLAG_NOWAIT | ARC_FLAG_PREFETCH;
2962 /* dnodes are always read as raw and then converted later */
2963 if (BP_GET_TYPE(bp) == DMU_OT_DNODE && BP_IS_PROTECTED(bp) &&
2964 dpa->dpa_curlevel == 0)
2965 zio_flags |= ZIO_FLAG_RAW;
2967 ASSERT3U(dpa->dpa_curlevel, ==, BP_GET_LEVEL(bp));
2968 ASSERT3U(dpa->dpa_curlevel, ==, dpa->dpa_zb.zb_level);
2969 ASSERT(dpa->dpa_zio != NULL);
2970 (void) arc_read(dpa->dpa_zio, dpa->dpa_spa, bp, NULL, NULL,
2971 dpa->dpa_prio, zio_flags, &aflags, &dpa->dpa_zb);
2975 * Called when an indirect block above our prefetch target is read in. This
2976 * will either read in the next indirect block down the tree or issue the actual
2977 * prefetch if the next block down is our target.
2980 dbuf_prefetch_indirect_done(zio_t *zio, const zbookmark_phys_t *zb,
2981 const blkptr_t *iobp, arc_buf_t *abuf, void *private)
2983 dbuf_prefetch_arg_t *dpa = private;
2985 ASSERT3S(dpa->dpa_zb.zb_level, <, dpa->dpa_curlevel);
2986 ASSERT3S(dpa->dpa_curlevel, >, 0);
2989 ASSERT(zio == NULL || zio->io_error != 0);
2990 kmem_free(dpa, sizeof (*dpa));
2993 ASSERT(zio == NULL || zio->io_error == 0);
2996 * The dpa_dnode is only valid if we are called with a NULL
2997 * zio. This indicates that the arc_read() returned without
2998 * first calling zio_read() to issue a physical read. Once
2999 * a physical read is made the dpa_dnode must be invalidated
3000 * as the locks guarding it may have been dropped. If the
3001 * dpa_dnode is still valid, then we want to add it to the dbuf
3002 * cache. To do so, we must hold the dbuf associated with the block
3003 * we just prefetched, read its contents so that we associate it
3004 * with an arc_buf_t, and then release it.
3007 ASSERT3S(BP_GET_LEVEL(zio->io_bp), ==, dpa->dpa_curlevel);
3008 if (zio->io_flags & ZIO_FLAG_RAW_COMPRESS) {
3009 ASSERT3U(BP_GET_PSIZE(zio->io_bp), ==, zio->io_size);
3011 ASSERT3U(BP_GET_LSIZE(zio->io_bp), ==, zio->io_size);
3013 ASSERT3P(zio->io_spa, ==, dpa->dpa_spa);
3015 dpa->dpa_dnode = NULL;
3016 } else if (dpa->dpa_dnode != NULL) {
3017 uint64_t curblkid = dpa->dpa_zb.zb_blkid >>
3018 (dpa->dpa_epbs * (dpa->dpa_curlevel -
3019 dpa->dpa_zb.zb_level));
3020 dmu_buf_impl_t *db = dbuf_hold_level(dpa->dpa_dnode,
3021 dpa->dpa_curlevel, curblkid, FTAG);
3023 kmem_free(dpa, sizeof (*dpa));
3024 arc_buf_destroy(abuf, private);
3028 (void) dbuf_read(db, NULL,
3029 DB_RF_MUST_SUCCEED | DB_RF_NOPREFETCH | DB_RF_HAVESTRUCT);
3030 dbuf_rele(db, FTAG);
3033 dpa->dpa_curlevel--;
3034 uint64_t nextblkid = dpa->dpa_zb.zb_blkid >>
3035 (dpa->dpa_epbs * (dpa->dpa_curlevel - dpa->dpa_zb.zb_level));
3036 blkptr_t *bp = ((blkptr_t *)abuf->b_data) +
3037 P2PHASE(nextblkid, 1ULL << dpa->dpa_epbs);
3039 ASSERT(!BP_IS_REDACTED(bp) ||
3040 dsl_dataset_feature_is_active(
3041 dpa->dpa_dnode->dn_objset->os_dsl_dataset,
3042 SPA_FEATURE_REDACTED_DATASETS));
3043 if (BP_IS_HOLE(bp) || BP_IS_REDACTED(bp)) {
3044 kmem_free(dpa, sizeof (*dpa));
3045 } else if (dpa->dpa_curlevel == dpa->dpa_zb.zb_level) {
3046 ASSERT3U(nextblkid, ==, dpa->dpa_zb.zb_blkid);
3047 dbuf_issue_final_prefetch(dpa, bp);
3048 kmem_free(dpa, sizeof (*dpa));
3050 arc_flags_t iter_aflags = ARC_FLAG_NOWAIT;
3051 zbookmark_phys_t zb;
3053 /* flag if L2ARC eligible, l2arc_noprefetch then decides */
3054 if (dpa->dpa_aflags & ARC_FLAG_L2CACHE)
3055 iter_aflags |= ARC_FLAG_L2CACHE;
3057 ASSERT3U(dpa->dpa_curlevel, ==, BP_GET_LEVEL(bp));
3059 SET_BOOKMARK(&zb, dpa->dpa_zb.zb_objset,
3060 dpa->dpa_zb.zb_object, dpa->dpa_curlevel, nextblkid);
3062 (void) arc_read(dpa->dpa_zio, dpa->dpa_spa,
3063 bp, dbuf_prefetch_indirect_done, dpa, dpa->dpa_prio,
3064 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE,
3068 arc_buf_destroy(abuf, private);
3072 * Issue prefetch reads for the given block on the given level. If the indirect
3073 * blocks above that block are not in memory, we will read them in
3074 * asynchronously. As a result, this call never blocks waiting for a read to
3075 * complete. Note that the prefetch might fail if the dataset is encrypted and
3076 * the encryption key is unmapped before the IO completes.
3079 dbuf_prefetch(dnode_t *dn, int64_t level, uint64_t blkid, zio_priority_t prio,
3083 int epbs, nlevels, curlevel;
3086 ASSERT(blkid != DMU_BONUS_BLKID);
3087 ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock));
3089 if (blkid > dn->dn_maxblkid)
3092 if (level == 0 && dnode_block_freed(dn, blkid))
3096 * This dnode hasn't been written to disk yet, so there's nothing to
3099 nlevels = dn->dn_phys->dn_nlevels;
3100 if (level >= nlevels || dn->dn_phys->dn_nblkptr == 0)
3103 epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
3104 if (dn->dn_phys->dn_maxblkid < blkid << (epbs * level))
3107 dmu_buf_impl_t *db = dbuf_find(dn->dn_objset, dn->dn_object,
3110 mutex_exit(&db->db_mtx);
3112 * This dbuf already exists. It is either CACHED, or
3113 * (we assume) about to be read or filled.
3119 * Find the closest ancestor (indirect block) of the target block
3120 * that is present in the cache. In this indirect block, we will
3121 * find the bp that is at curlevel, curblkid.
3125 while (curlevel < nlevels - 1) {
3126 int parent_level = curlevel + 1;
3127 uint64_t parent_blkid = curblkid >> epbs;
3130 if (dbuf_hold_impl(dn, parent_level, parent_blkid,
3131 FALSE, TRUE, FTAG, &db) == 0) {
3132 blkptr_t *bpp = db->db_buf->b_data;
3133 bp = bpp[P2PHASE(curblkid, 1 << epbs)];
3134 dbuf_rele(db, FTAG);
3138 curlevel = parent_level;
3139 curblkid = parent_blkid;
3142 if (curlevel == nlevels - 1) {
3143 /* No cached indirect blocks found. */
3144 ASSERT3U(curblkid, <, dn->dn_phys->dn_nblkptr);
3145 bp = dn->dn_phys->dn_blkptr[curblkid];
3147 ASSERT(!BP_IS_REDACTED(&bp) ||
3148 dsl_dataset_feature_is_active(dn->dn_objset->os_dsl_dataset,
3149 SPA_FEATURE_REDACTED_DATASETS));
3150 if (BP_IS_HOLE(&bp) || BP_IS_REDACTED(&bp))
3153 ASSERT3U(curlevel, ==, BP_GET_LEVEL(&bp));
3155 zio_t *pio = zio_root(dmu_objset_spa(dn->dn_objset), NULL, NULL,
3158 dbuf_prefetch_arg_t *dpa = kmem_zalloc(sizeof (*dpa), KM_SLEEP);
3159 dsl_dataset_t *ds = dn->dn_objset->os_dsl_dataset;
3160 SET_BOOKMARK(&dpa->dpa_zb, ds != NULL ? ds->ds_object : DMU_META_OBJSET,
3161 dn->dn_object, level, blkid);
3162 dpa->dpa_curlevel = curlevel;
3163 dpa->dpa_prio = prio;
3164 dpa->dpa_aflags = aflags;
3165 dpa->dpa_spa = dn->dn_objset->os_spa;
3166 dpa->dpa_dnode = dn;
3167 dpa->dpa_epbs = epbs;
3170 /* flag if L2ARC eligible, l2arc_noprefetch then decides */
3171 if (DNODE_LEVEL_IS_L2CACHEABLE(dn, level))
3172 dpa->dpa_aflags |= ARC_FLAG_L2CACHE;
3175 * If we have the indirect just above us, no need to do the asynchronous
3176 * prefetch chain; we'll just run the last step ourselves. If we're at
3177 * a higher level, though, we want to issue the prefetches for all the
3178 * indirect blocks asynchronously, so we can go on with whatever we were
3181 if (curlevel == level) {
3182 ASSERT3U(curblkid, ==, blkid);
3183 dbuf_issue_final_prefetch(dpa, &bp);
3184 kmem_free(dpa, sizeof (*dpa));
3186 arc_flags_t iter_aflags = ARC_FLAG_NOWAIT;
3187 zbookmark_phys_t zb;
3189 /* flag if L2ARC eligible, l2arc_noprefetch then decides */
3190 if (DNODE_LEVEL_IS_L2CACHEABLE(dn, level))
3191 iter_aflags |= ARC_FLAG_L2CACHE;
3193 SET_BOOKMARK(&zb, ds != NULL ? ds->ds_object : DMU_META_OBJSET,
3194 dn->dn_object, curlevel, curblkid);
3195 (void) arc_read(dpa->dpa_zio, dpa->dpa_spa,
3196 &bp, dbuf_prefetch_indirect_done, dpa, prio,
3197 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE,
3201 * We use pio here instead of dpa_zio since it's possible that
3202 * dpa may have already been freed.
3208 * Helper function for dbuf_hold_impl() to copy a buffer. Handles
3209 * the case of encrypted, compressed and uncompressed buffers by
3210 * allocating the new buffer, respectively, with arc_alloc_raw_buf(),
3211 * arc_alloc_compressed_buf() or arc_alloc_buf().*
3213 * NOTE: Declared noinline to avoid stack bloat in dbuf_hold_impl().
3215 noinline static void
3216 dbuf_hold_copy(dnode_t *dn, dmu_buf_impl_t *db)
3218 dbuf_dirty_record_t *dr = db->db_data_pending;
3219 arc_buf_t *data = dr->dt.dl.dr_data;
3220 enum zio_compress compress_type = arc_get_compression(data);
3222 if (arc_is_encrypted(data)) {
3223 boolean_t byteorder;
3224 uint8_t salt[ZIO_DATA_SALT_LEN];
3225 uint8_t iv[ZIO_DATA_IV_LEN];
3226 uint8_t mac[ZIO_DATA_MAC_LEN];
3228 arc_get_raw_params(data, &byteorder, salt, iv, mac);
3229 dbuf_set_data(db, arc_alloc_raw_buf(dn->dn_objset->os_spa, db,
3230 dmu_objset_id(dn->dn_objset), byteorder, salt, iv, mac,
3231 dn->dn_type, arc_buf_size(data), arc_buf_lsize(data),
3233 } else if (compress_type != ZIO_COMPRESS_OFF) {
3234 dbuf_set_data(db, arc_alloc_compressed_buf(
3235 dn->dn_objset->os_spa, db, arc_buf_size(data),
3236 arc_buf_lsize(data), compress_type));
3238 dbuf_set_data(db, arc_alloc_buf(dn->dn_objset->os_spa, db,
3239 DBUF_GET_BUFC_TYPE(db), db->db.db_size));
3242 rw_enter(&db->db_rwlock, RW_WRITER);
3243 bcopy(data->b_data, db->db.db_data, arc_buf_size(data));
3244 rw_exit(&db->db_rwlock);
3248 * Returns with db_holds incremented, and db_mtx not held.
3249 * Note: dn_struct_rwlock must be held.
3252 dbuf_hold_impl(dnode_t *dn, uint8_t level, uint64_t blkid,
3253 boolean_t fail_sparse, boolean_t fail_uncached,
3254 void *tag, dmu_buf_impl_t **dbp)
3256 dmu_buf_impl_t *db, *parent = NULL;
3258 /* If the pool has been created, verify the tx_sync_lock is not held */
3259 spa_t *spa = dn->dn_objset->os_spa;
3260 dsl_pool_t *dp = spa->spa_dsl_pool;
3262 ASSERT(!MUTEX_HELD(&dp->dp_tx.tx_sync_lock));
3265 ASSERT(blkid != DMU_BONUS_BLKID);
3266 ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock));
3267 ASSERT3U(dn->dn_nlevels, >, level);
3271 /* dbuf_find() returns with db_mtx held */
3272 db = dbuf_find(dn->dn_objset, dn->dn_object, level, blkid);
3275 blkptr_t *bp = NULL;
3279 return (SET_ERROR(ENOENT));
3281 ASSERT3P(parent, ==, NULL);
3282 err = dbuf_findbp(dn, level, blkid, fail_sparse, &parent, &bp);
3284 if (err == 0 && bp && BP_IS_HOLE(bp))
3285 err = SET_ERROR(ENOENT);
3288 dbuf_rele(parent, NULL);
3292 if (err && err != ENOENT)
3294 db = dbuf_create(dn, level, blkid, parent, bp);
3297 if (fail_uncached && db->db_state != DB_CACHED) {
3298 mutex_exit(&db->db_mtx);
3299 return (SET_ERROR(ENOENT));
3302 if (db->db_buf != NULL) {
3303 arc_buf_access(db->db_buf);
3304 ASSERT3P(db->db.db_data, ==, db->db_buf->b_data);
3307 ASSERT(db->db_buf == NULL || arc_referenced(db->db_buf));
3310 * If this buffer is currently syncing out, and we are
3311 * still referencing it from db_data, we need to make a copy
3312 * of it in case we decide we want to dirty it again in this txg.
3314 if (db->db_level == 0 && db->db_blkid != DMU_BONUS_BLKID &&
3315 dn->dn_object != DMU_META_DNODE_OBJECT &&
3316 db->db_state == DB_CACHED && db->db_data_pending) {
3317 dbuf_dirty_record_t *dr = db->db_data_pending;
3318 if (dr->dt.dl.dr_data == db->db_buf)
3319 dbuf_hold_copy(dn, db);
3322 if (multilist_link_active(&db->db_cache_link)) {
3323 ASSERT(zfs_refcount_is_zero(&db->db_holds));
3324 ASSERT(db->db_caching_status == DB_DBUF_CACHE ||
3325 db->db_caching_status == DB_DBUF_METADATA_CACHE);
3327 multilist_remove(dbuf_caches[db->db_caching_status].cache, db);
3328 (void) zfs_refcount_remove_many(
3329 &dbuf_caches[db->db_caching_status].size,
3330 db->db.db_size, db);
3332 if (db->db_caching_status == DB_DBUF_METADATA_CACHE) {
3333 DBUF_STAT_BUMPDOWN(metadata_cache_count);
3335 DBUF_STAT_BUMPDOWN(cache_levels[db->db_level]);
3336 DBUF_STAT_BUMPDOWN(cache_count);
3337 DBUF_STAT_DECR(cache_levels_bytes[db->db_level],
3340 db->db_caching_status = DB_NO_CACHE;
3342 (void) zfs_refcount_add(&db->db_holds, tag);
3344 mutex_exit(&db->db_mtx);
3346 /* NOTE: we can't rele the parent until after we drop the db_mtx */
3348 dbuf_rele(parent, NULL);
3350 ASSERT3P(DB_DNODE(db), ==, dn);
3351 ASSERT3U(db->db_blkid, ==, blkid);
3352 ASSERT3U(db->db_level, ==, level);
3359 dbuf_hold(dnode_t *dn, uint64_t blkid, void *tag)
3361 return (dbuf_hold_level(dn, 0, blkid, tag));
3365 dbuf_hold_level(dnode_t *dn, int level, uint64_t blkid, void *tag)
3368 int err = dbuf_hold_impl(dn, level, blkid, FALSE, FALSE, tag, &db);
3369 return (err ? NULL : db);
3373 dbuf_create_bonus(dnode_t *dn)
3375 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
3377 ASSERT(dn->dn_bonus == NULL);
3378 dn->dn_bonus = dbuf_create(dn, 0, DMU_BONUS_BLKID, dn->dn_dbuf, NULL);
3382 dbuf_spill_set_blksz(dmu_buf_t *db_fake, uint64_t blksz, dmu_tx_t *tx)
3384 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
3386 if (db->db_blkid != DMU_SPILL_BLKID)
3387 return (SET_ERROR(ENOTSUP));
3389 blksz = SPA_MINBLOCKSIZE;
3390 ASSERT3U(blksz, <=, spa_maxblocksize(dmu_objset_spa(db->db_objset)));
3391 blksz = P2ROUNDUP(blksz, SPA_MINBLOCKSIZE);
3393 dbuf_new_size(db, blksz, tx);
3399 dbuf_rm_spill(dnode_t *dn, dmu_tx_t *tx)
3401 dbuf_free_range(dn, DMU_SPILL_BLKID, DMU_SPILL_BLKID, tx);
3404 #pragma weak dmu_buf_add_ref = dbuf_add_ref
3406 dbuf_add_ref(dmu_buf_impl_t *db, void *tag)
3408 int64_t holds = zfs_refcount_add(&db->db_holds, tag);
3409 VERIFY3S(holds, >, 1);
3412 #pragma weak dmu_buf_try_add_ref = dbuf_try_add_ref
3414 dbuf_try_add_ref(dmu_buf_t *db_fake, objset_t *os, uint64_t obj, uint64_t blkid,
3417 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
3418 dmu_buf_impl_t *found_db;
3419 boolean_t result = B_FALSE;
3421 if (blkid == DMU_BONUS_BLKID)
3422 found_db = dbuf_find_bonus(os, obj);
3424 found_db = dbuf_find(os, obj, 0, blkid);
3426 if (found_db != NULL) {
3427 if (db == found_db && dbuf_refcount(db) > db->db_dirtycnt) {
3428 (void) zfs_refcount_add(&db->db_holds, tag);
3431 mutex_exit(&found_db->db_mtx);
3437 * If you call dbuf_rele() you had better not be referencing the dnode handle
3438 * unless you have some other direct or indirect hold on the dnode. (An indirect
3439 * hold is a hold on one of the dnode's dbufs, including the bonus buffer.)
3440 * Without that, the dbuf_rele() could lead to a dnode_rele() followed by the
3441 * dnode's parent dbuf evicting its dnode handles.
3444 dbuf_rele(dmu_buf_impl_t *db, void *tag)
3446 mutex_enter(&db->db_mtx);
3447 dbuf_rele_and_unlock(db, tag, B_FALSE);
3451 dmu_buf_rele(dmu_buf_t *db, void *tag)
3453 dbuf_rele((dmu_buf_impl_t *)db, tag);
3457 * dbuf_rele() for an already-locked dbuf. This is necessary to allow
3458 * db_dirtycnt and db_holds to be updated atomically. The 'evicting'
3459 * argument should be set if we are already in the dbuf-evicting code
3460 * path, in which case we don't want to recursively evict. This allows us to
3461 * avoid deeply nested stacks that would have a call flow similar to this:
3463 * dbuf_rele()-->dbuf_rele_and_unlock()-->dbuf_evict_notify()
3466 * +-----dbuf_destroy()<--dbuf_evict_one()<--------+
3470 dbuf_rele_and_unlock(dmu_buf_impl_t *db, void *tag, boolean_t evicting)
3474 ASSERT(MUTEX_HELD(&db->db_mtx));
3478 * Remove the reference to the dbuf before removing its hold on the
3479 * dnode so we can guarantee in dnode_move() that a referenced bonus
3480 * buffer has a corresponding dnode hold.
3482 holds = zfs_refcount_remove(&db->db_holds, tag);
3486 * We can't freeze indirects if there is a possibility that they
3487 * may be modified in the current syncing context.
3489 if (db->db_buf != NULL &&
3490 holds == (db->db_level == 0 ? db->db_dirtycnt : 0)) {
3491 arc_buf_freeze(db->db_buf);
3494 if (holds == db->db_dirtycnt &&
3495 db->db_level == 0 && db->db_user_immediate_evict)
3496 dbuf_evict_user(db);
3499 if (db->db_blkid == DMU_BONUS_BLKID) {
3501 boolean_t evict_dbuf = db->db_pending_evict;
3504 * If the dnode moves here, we cannot cross this
3505 * barrier until the move completes.
3510 atomic_dec_32(&dn->dn_dbufs_count);
3513 * Decrementing the dbuf count means that the bonus
3514 * buffer's dnode hold is no longer discounted in
3515 * dnode_move(). The dnode cannot move until after
3516 * the dnode_rele() below.
3521 * Do not reference db after its lock is dropped.
3522 * Another thread may evict it.
3524 mutex_exit(&db->db_mtx);
3527 dnode_evict_bonus(dn);
3530 } else if (db->db_buf == NULL) {
3532 * This is a special case: we never associated this
3533 * dbuf with any data allocated from the ARC.
3535 ASSERT(db->db_state == DB_UNCACHED ||
3536 db->db_state == DB_NOFILL);
3538 } else if (arc_released(db->db_buf)) {
3540 * This dbuf has anonymous data associated with it.
3544 boolean_t do_arc_evict = B_FALSE;
3546 spa_t *spa = dmu_objset_spa(db->db_objset);
3548 if (!DBUF_IS_CACHEABLE(db) &&
3549 db->db_blkptr != NULL &&
3550 !BP_IS_HOLE(db->db_blkptr) &&
3551 !BP_IS_EMBEDDED(db->db_blkptr)) {
3552 do_arc_evict = B_TRUE;
3553 bp = *db->db_blkptr;
3556 if (!DBUF_IS_CACHEABLE(db) ||
3557 db->db_pending_evict) {
3559 } else if (!multilist_link_active(&db->db_cache_link)) {
3560 ASSERT3U(db->db_caching_status, ==,
3563 dbuf_cached_state_t dcs =
3564 dbuf_include_in_metadata_cache(db) ?
3565 DB_DBUF_METADATA_CACHE : DB_DBUF_CACHE;
3566 db->db_caching_status = dcs;
3568 multilist_insert(dbuf_caches[dcs].cache, db);
3569 (void) zfs_refcount_add_many(
3570 &dbuf_caches[dcs].size,
3571 db->db.db_size, db);
3573 if (dcs == DB_DBUF_METADATA_CACHE) {
3574 DBUF_STAT_BUMP(metadata_cache_count);
3576 metadata_cache_size_bytes_max,
3578 &dbuf_caches[dcs].size));
3581 cache_levels[db->db_level]);
3582 DBUF_STAT_BUMP(cache_count);
3584 cache_levels_bytes[db->db_level],
3586 DBUF_STAT_MAX(cache_size_bytes_max,
3588 &dbuf_caches[dcs].size));
3590 mutex_exit(&db->db_mtx);
3592 if (db->db_caching_status == DB_DBUF_CACHE &&
3594 dbuf_evict_notify();
3599 arc_freed(spa, &bp);
3602 mutex_exit(&db->db_mtx);
3607 #pragma weak dmu_buf_refcount = dbuf_refcount
3609 dbuf_refcount(dmu_buf_impl_t *db)
3611 return (zfs_refcount_count(&db->db_holds));
3615 dmu_buf_user_refcount(dmu_buf_t *db_fake)
3618 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
3620 mutex_enter(&db->db_mtx);
3621 ASSERT3U(zfs_refcount_count(&db->db_holds), >=, db->db_dirtycnt);
3622 holds = zfs_refcount_count(&db->db_holds) - db->db_dirtycnt;
3623 mutex_exit(&db->db_mtx);
3629 dmu_buf_replace_user(dmu_buf_t *db_fake, dmu_buf_user_t *old_user,
3630 dmu_buf_user_t *new_user)
3632 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
3634 mutex_enter(&db->db_mtx);
3635 dbuf_verify_user(db, DBVU_NOT_EVICTING);
3636 if (db->db_user == old_user)
3637 db->db_user = new_user;
3639 old_user = db->db_user;
3640 dbuf_verify_user(db, DBVU_NOT_EVICTING);
3641 mutex_exit(&db->db_mtx);
3647 dmu_buf_set_user(dmu_buf_t *db_fake, dmu_buf_user_t *user)
3649 return (dmu_buf_replace_user(db_fake, NULL, user));
3653 dmu_buf_set_user_ie(dmu_buf_t *db_fake, dmu_buf_user_t *user)
3655 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
3657 db->db_user_immediate_evict = TRUE;
3658 return (dmu_buf_set_user(db_fake, user));
3662 dmu_buf_remove_user(dmu_buf_t *db_fake, dmu_buf_user_t *user)
3664 return (dmu_buf_replace_user(db_fake, user, NULL));
3668 dmu_buf_get_user(dmu_buf_t *db_fake)
3670 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
3672 dbuf_verify_user(db, DBVU_NOT_EVICTING);
3673 return (db->db_user);
3677 dmu_buf_user_evict_wait()
3679 taskq_wait(dbu_evict_taskq);
3683 dmu_buf_get_blkptr(dmu_buf_t *db)
3685 dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db;
3686 return (dbi->db_blkptr);
3690 dmu_buf_get_objset(dmu_buf_t *db)
3692 dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db;
3693 return (dbi->db_objset);
3697 dmu_buf_dnode_enter(dmu_buf_t *db)
3699 dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db;
3700 DB_DNODE_ENTER(dbi);
3701 return (DB_DNODE(dbi));
3705 dmu_buf_dnode_exit(dmu_buf_t *db)
3707 dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db;
3712 dbuf_check_blkptr(dnode_t *dn, dmu_buf_impl_t *db)
3714 /* ASSERT(dmu_tx_is_syncing(tx) */
3715 ASSERT(MUTEX_HELD(&db->db_mtx));
3717 if (db->db_blkptr != NULL)
3720 if (db->db_blkid == DMU_SPILL_BLKID) {
3721 db->db_blkptr = DN_SPILL_BLKPTR(dn->dn_phys);
3722 BP_ZERO(db->db_blkptr);
3725 if (db->db_level == dn->dn_phys->dn_nlevels-1) {
3727 * This buffer was allocated at a time when there was
3728 * no available blkptrs from the dnode, or it was
3729 * inappropriate to hook it in (i.e., nlevels mismatch).
3731 ASSERT(db->db_blkid < dn->dn_phys->dn_nblkptr);
3732 ASSERT(db->db_parent == NULL);
3733 db->db_parent = dn->dn_dbuf;
3734 db->db_blkptr = &dn->dn_phys->dn_blkptr[db->db_blkid];
3737 dmu_buf_impl_t *parent = db->db_parent;
3738 int epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
3740 ASSERT(dn->dn_phys->dn_nlevels > 1);
3741 if (parent == NULL) {
3742 mutex_exit(&db->db_mtx);
3743 rw_enter(&dn->dn_struct_rwlock, RW_READER);
3744 parent = dbuf_hold_level(dn, db->db_level + 1,
3745 db->db_blkid >> epbs, db);
3746 rw_exit(&dn->dn_struct_rwlock);
3747 mutex_enter(&db->db_mtx);
3748 db->db_parent = parent;
3750 db->db_blkptr = (blkptr_t *)parent->db.db_data +
3751 (db->db_blkid & ((1ULL << epbs) - 1));
3757 * When syncing out a blocks of dnodes, adjust the block to deal with
3758 * encryption. Normally, we make sure the block is decrypted before writing
3759 * it. If we have crypt params, then we are writing a raw (encrypted) block,
3760 * from a raw receive. In this case, set the ARC buf's crypt params so
3761 * that the BP will be filled with the correct byteorder, salt, iv, and mac.
3764 dbuf_prepare_encrypted_dnode_leaf(dbuf_dirty_record_t *dr)
3767 dmu_buf_impl_t *db = dr->dr_dbuf;
3769 ASSERT(MUTEX_HELD(&db->db_mtx));
3770 ASSERT3U(db->db.db_object, ==, DMU_META_DNODE_OBJECT);
3771 ASSERT3U(db->db_level, ==, 0);
3773 if (!db->db_objset->os_raw_receive && arc_is_encrypted(db->db_buf)) {
3774 zbookmark_phys_t zb;
3777 * Unfortunately, there is currently no mechanism for
3778 * syncing context to handle decryption errors. An error
3779 * here is only possible if an attacker maliciously
3780 * changed a dnode block and updated the associated
3781 * checksums going up the block tree.
3783 SET_BOOKMARK(&zb, dmu_objset_id(db->db_objset),
3784 db->db.db_object, db->db_level, db->db_blkid);
3785 err = arc_untransform(db->db_buf, db->db_objset->os_spa,
3788 panic("Invalid dnode block MAC");
3789 } else if (dr->dt.dl.dr_has_raw_params) {
3790 (void) arc_release(dr->dt.dl.dr_data, db);
3791 arc_convert_to_raw(dr->dt.dl.dr_data,
3792 dmu_objset_id(db->db_objset),
3793 dr->dt.dl.dr_byteorder, DMU_OT_DNODE,
3794 dr->dt.dl.dr_salt, dr->dt.dl.dr_iv, dr->dt.dl.dr_mac);
3799 * dbuf_sync_indirect() is called recursively from dbuf_sync_list() so it
3800 * is critical the we not allow the compiler to inline this function in to
3801 * dbuf_sync_list() thereby drastically bloating the stack usage.
3803 noinline static void
3804 dbuf_sync_indirect(dbuf_dirty_record_t *dr, dmu_tx_t *tx)
3806 dmu_buf_impl_t *db = dr->dr_dbuf;
3810 ASSERT(dmu_tx_is_syncing(tx));
3812 dprintf_dbuf_bp(db, db->db_blkptr, "blkptr=%p", db->db_blkptr);
3814 mutex_enter(&db->db_mtx);
3816 ASSERT(db->db_level > 0);
3819 /* Read the block if it hasn't been read yet. */
3820 if (db->db_buf == NULL) {
3821 mutex_exit(&db->db_mtx);
3822 (void) dbuf_read(db, NULL, DB_RF_MUST_SUCCEED);
3823 mutex_enter(&db->db_mtx);
3825 ASSERT3U(db->db_state, ==, DB_CACHED);
3826 ASSERT(db->db_buf != NULL);
3830 /* Indirect block size must match what the dnode thinks it is. */
3831 ASSERT3U(db->db.db_size, ==, 1<<dn->dn_phys->dn_indblkshift);
3832 dbuf_check_blkptr(dn, db);
3835 /* Provide the pending dirty record to child dbufs */
3836 db->db_data_pending = dr;
3838 mutex_exit(&db->db_mtx);
3840 dbuf_write(dr, db->db_buf, tx);
3843 mutex_enter(&dr->dt.di.dr_mtx);
3844 dbuf_sync_list(&dr->dt.di.dr_children, db->db_level - 1, tx);
3845 ASSERT(list_head(&dr->dt.di.dr_children) == NULL);
3846 mutex_exit(&dr->dt.di.dr_mtx);
3852 * Verify that the size of the data in our bonus buffer does not exceed
3853 * its recorded size.
3855 * The purpose of this verification is to catch any cases in development
3856 * where the size of a phys structure (i.e space_map_phys_t) grows and,
3857 * due to incorrect feature management, older pools expect to read more
3858 * data even though they didn't actually write it to begin with.
3860 * For a example, this would catch an error in the feature logic where we
3861 * open an older pool and we expect to write the space map histogram of
3862 * a space map with size SPACE_MAP_SIZE_V0.
3865 dbuf_sync_leaf_verify_bonus_dnode(dbuf_dirty_record_t *dr)
3867 dnode_t *dn = DB_DNODE(dr->dr_dbuf);
3870 * Encrypted bonus buffers can have data past their bonuslen.
3871 * Skip the verification of these blocks.
3873 if (DMU_OT_IS_ENCRYPTED(dn->dn_bonustype))
3876 uint16_t bonuslen = dn->dn_phys->dn_bonuslen;
3877 uint16_t maxbonuslen = DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots);
3878 ASSERT3U(bonuslen, <=, maxbonuslen);
3880 arc_buf_t *datap = dr->dt.dl.dr_data;
3881 char *datap_end = ((char *)datap) + bonuslen;
3882 char *datap_max = ((char *)datap) + maxbonuslen;
3884 /* ensure that everything is zero after our data */
3885 for (; datap_end < datap_max; datap_end++)
3886 ASSERT(*datap_end == 0);
3891 * dbuf_sync_leaf() is called recursively from dbuf_sync_list() so it is
3892 * critical the we not allow the compiler to inline this function in to
3893 * dbuf_sync_list() thereby drastically bloating the stack usage.
3895 noinline static void
3896 dbuf_sync_leaf(dbuf_dirty_record_t *dr, dmu_tx_t *tx)
3898 arc_buf_t **datap = &dr->dt.dl.dr_data;
3899 dmu_buf_impl_t *db = dr->dr_dbuf;
3902 uint64_t txg = tx->tx_txg;
3904 ASSERT(dmu_tx_is_syncing(tx));
3906 dprintf_dbuf_bp(db, db->db_blkptr, "blkptr=%p", db->db_blkptr);
3908 mutex_enter(&db->db_mtx);
3910 * To be synced, we must be dirtied. But we
3911 * might have been freed after the dirty.
3913 if (db->db_state == DB_UNCACHED) {
3914 /* This buffer has been freed since it was dirtied */
3915 ASSERT(db->db.db_data == NULL);
3916 } else if (db->db_state == DB_FILL) {
3917 /* This buffer was freed and is now being re-filled */
3918 ASSERT(db->db.db_data != dr->dt.dl.dr_data);
3920 ASSERT(db->db_state == DB_CACHED || db->db_state == DB_NOFILL);
3927 if (db->db_blkid == DMU_SPILL_BLKID) {
3928 mutex_enter(&dn->dn_mtx);
3929 if (!(dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR)) {
3931 * In the previous transaction group, the bonus buffer
3932 * was entirely used to store the attributes for the
3933 * dnode which overrode the dn_spill field. However,
3934 * when adding more attributes to the file a spill
3935 * block was required to hold the extra attributes.
3937 * Make sure to clear the garbage left in the dn_spill
3938 * field from the previous attributes in the bonus
3939 * buffer. Otherwise, after writing out the spill
3940 * block to the new allocated dva, it will free
3941 * the old block pointed to by the invalid dn_spill.
3943 db->db_blkptr = NULL;
3945 dn->dn_phys->dn_flags |= DNODE_FLAG_SPILL_BLKPTR;
3946 mutex_exit(&dn->dn_mtx);
3950 * If this is a bonus buffer, simply copy the bonus data into the
3951 * dnode. It will be written out when the dnode is synced (and it
3952 * will be synced, since it must have been dirty for dbuf_sync to
3955 if (db->db_blkid == DMU_BONUS_BLKID) {
3956 dbuf_dirty_record_t **drp;
3958 ASSERT(*datap != NULL);
3959 ASSERT0(db->db_level);
3960 ASSERT3U(DN_MAX_BONUS_LEN(dn->dn_phys), <=,
3961 DN_SLOTS_TO_BONUSLEN(dn->dn_phys->dn_extra_slots + 1));
3962 bcopy(*datap, DN_BONUS(dn->dn_phys),
3963 DN_MAX_BONUS_LEN(dn->dn_phys));
3967 dbuf_sync_leaf_verify_bonus_dnode(dr);
3970 if (*datap != db->db.db_data) {
3971 int slots = DB_DNODE(db)->dn_num_slots;
3972 int bonuslen = DN_SLOTS_TO_BONUSLEN(slots);
3973 kmem_free(*datap, bonuslen);
3974 arc_space_return(bonuslen, ARC_SPACE_BONUS);
3976 db->db_data_pending = NULL;
3977 drp = &db->db_last_dirty;
3979 drp = &(*drp)->dr_next;
3980 ASSERT(dr->dr_next == NULL);
3981 ASSERT(dr->dr_dbuf == db);
3983 if (dr->dr_dbuf->db_level != 0) {
3984 mutex_destroy(&dr->dt.di.dr_mtx);
3985 list_destroy(&dr->dt.di.dr_children);
3987 kmem_free(dr, sizeof (dbuf_dirty_record_t));
3988 ASSERT(db->db_dirtycnt > 0);
3989 db->db_dirtycnt -= 1;
3990 dbuf_rele_and_unlock(db, (void *)(uintptr_t)txg, B_FALSE);
3997 * This function may have dropped the db_mtx lock allowing a dmu_sync
3998 * operation to sneak in. As a result, we need to ensure that we
3999 * don't check the dr_override_state until we have returned from
4000 * dbuf_check_blkptr.
4002 dbuf_check_blkptr(dn, db);
4005 * If this buffer is in the middle of an immediate write,
4006 * wait for the synchronous IO to complete.
4008 while (dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC) {
4009 ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT);
4010 cv_wait(&db->db_changed, &db->db_mtx);
4011 ASSERT(dr->dt.dl.dr_override_state != DR_NOT_OVERRIDDEN);
4015 * If this is a dnode block, ensure it is appropriately encrypted
4016 * or decrypted, depending on what we are writing to it this txg.
4018 if (os->os_encrypted && dn->dn_object == DMU_META_DNODE_OBJECT)
4019 dbuf_prepare_encrypted_dnode_leaf(dr);
4021 if (db->db_state != DB_NOFILL &&
4022 dn->dn_object != DMU_META_DNODE_OBJECT &&
4023 zfs_refcount_count(&db->db_holds) > 1 &&
4024 dr->dt.dl.dr_override_state != DR_OVERRIDDEN &&
4025 *datap == db->db_buf) {
4027 * If this buffer is currently "in use" (i.e., there
4028 * are active holds and db_data still references it),
4029 * then make a copy before we start the write so that
4030 * any modifications from the open txg will not leak
4033 * NOTE: this copy does not need to be made for
4034 * objects only modified in the syncing context (e.g.
4035 * DNONE_DNODE blocks).
4037 int psize = arc_buf_size(*datap);
4038 int lsize = arc_buf_lsize(*datap);
4039 arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db);
4040 enum zio_compress compress_type = arc_get_compression(*datap);
4042 if (arc_is_encrypted(*datap)) {
4043 boolean_t byteorder;
4044 uint8_t salt[ZIO_DATA_SALT_LEN];
4045 uint8_t iv[ZIO_DATA_IV_LEN];
4046 uint8_t mac[ZIO_DATA_MAC_LEN];
4048 arc_get_raw_params(*datap, &byteorder, salt, iv, mac);
4049 *datap = arc_alloc_raw_buf(os->os_spa, db,
4050 dmu_objset_id(os), byteorder, salt, iv, mac,
4051 dn->dn_type, psize, lsize, compress_type);
4052 } else if (compress_type != ZIO_COMPRESS_OFF) {
4053 ASSERT3U(type, ==, ARC_BUFC_DATA);
4054 *datap = arc_alloc_compressed_buf(os->os_spa, db,
4055 psize, lsize, compress_type);
4057 *datap = arc_alloc_buf(os->os_spa, db, type, psize);
4059 bcopy(db->db.db_data, (*datap)->b_data, psize);
4061 db->db_data_pending = dr;
4063 mutex_exit(&db->db_mtx);
4065 dbuf_write(dr, *datap, tx);
4067 ASSERT(!list_link_active(&dr->dr_dirty_node));
4068 if (dn->dn_object == DMU_META_DNODE_OBJECT) {
4069 list_insert_tail(&dn->dn_dirty_records[txg & TXG_MASK], dr);
4073 * Although zio_nowait() does not "wait for an IO", it does
4074 * initiate the IO. If this is an empty write it seems plausible
4075 * that the IO could actually be completed before the nowait
4076 * returns. We need to DB_DNODE_EXIT() first in case
4077 * zio_nowait() invalidates the dbuf.
4080 zio_nowait(dr->dr_zio);
4085 dbuf_sync_list(list_t *list, int level, dmu_tx_t *tx)
4087 dbuf_dirty_record_t *dr;
4089 while ((dr = list_head(list))) {
4090 if (dr->dr_zio != NULL) {
4092 * If we find an already initialized zio then we
4093 * are processing the meta-dnode, and we have finished.
4094 * The dbufs for all dnodes are put back on the list
4095 * during processing, so that we can zio_wait()
4096 * these IOs after initiating all child IOs.
4098 ASSERT3U(dr->dr_dbuf->db.db_object, ==,
4099 DMU_META_DNODE_OBJECT);
4102 if (dr->dr_dbuf->db_blkid != DMU_BONUS_BLKID &&
4103 dr->dr_dbuf->db_blkid != DMU_SPILL_BLKID) {
4104 VERIFY3U(dr->dr_dbuf->db_level, ==, level);
4106 list_remove(list, dr);
4107 if (dr->dr_dbuf->db_level > 0)
4108 dbuf_sync_indirect(dr, tx);
4110 dbuf_sync_leaf(dr, tx);
4116 dbuf_write_ready(zio_t *zio, arc_buf_t *buf, void *vdb)
4118 dmu_buf_impl_t *db = vdb;
4120 blkptr_t *bp = zio->io_bp;
4121 blkptr_t *bp_orig = &zio->io_bp_orig;
4122 spa_t *spa = zio->io_spa;
4127 ASSERT3P(db->db_blkptr, !=, NULL);
4128 ASSERT3P(&db->db_data_pending->dr_bp_copy, ==, bp);
4132 delta = bp_get_dsize_sync(spa, bp) - bp_get_dsize_sync(spa, bp_orig);
4133 dnode_diduse_space(dn, delta - zio->io_prev_space_delta);
4134 zio->io_prev_space_delta = delta;
4136 if (bp->blk_birth != 0) {
4137 ASSERT((db->db_blkid != DMU_SPILL_BLKID &&
4138 BP_GET_TYPE(bp) == dn->dn_type) ||
4139 (db->db_blkid == DMU_SPILL_BLKID &&
4140 BP_GET_TYPE(bp) == dn->dn_bonustype) ||
4141 BP_IS_EMBEDDED(bp));
4142 ASSERT(BP_GET_LEVEL(bp) == db->db_level);
4145 mutex_enter(&db->db_mtx);
4148 if (db->db_blkid == DMU_SPILL_BLKID) {
4149 ASSERT(dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR);
4150 ASSERT(!(BP_IS_HOLE(bp)) &&
4151 db->db_blkptr == DN_SPILL_BLKPTR(dn->dn_phys));
4155 if (db->db_level == 0) {
4156 mutex_enter(&dn->dn_mtx);
4157 if (db->db_blkid > dn->dn_phys->dn_maxblkid &&
4158 db->db_blkid != DMU_SPILL_BLKID) {
4159 ASSERT0(db->db_objset->os_raw_receive);
4160 dn->dn_phys->dn_maxblkid = db->db_blkid;
4162 mutex_exit(&dn->dn_mtx);
4164 if (dn->dn_type == DMU_OT_DNODE) {
4166 while (i < db->db.db_size) {
4168 (void *)(((char *)db->db.db_data) + i);
4170 i += DNODE_MIN_SIZE;
4171 if (dnp->dn_type != DMU_OT_NONE) {
4173 i += dnp->dn_extra_slots *
4178 if (BP_IS_HOLE(bp)) {
4185 blkptr_t *ibp = db->db.db_data;
4186 ASSERT3U(db->db.db_size, ==, 1<<dn->dn_phys->dn_indblkshift);
4187 for (i = db->db.db_size >> SPA_BLKPTRSHIFT; i > 0; i--, ibp++) {
4188 if (BP_IS_HOLE(ibp))
4190 fill += BP_GET_FILL(ibp);
4195 if (!BP_IS_EMBEDDED(bp))
4196 BP_SET_FILL(bp, fill);
4198 mutex_exit(&db->db_mtx);
4200 db_lock_type_t dblt = dmu_buf_lock_parent(db, RW_WRITER, FTAG);
4201 *db->db_blkptr = *bp;
4202 dmu_buf_unlock_parent(db, dblt, FTAG);
4207 * This function gets called just prior to running through the compression
4208 * stage of the zio pipeline. If we're an indirect block comprised of only
4209 * holes, then we want this indirect to be compressed away to a hole. In
4210 * order to do that we must zero out any information about the holes that
4211 * this indirect points to prior to before we try to compress it.
4214 dbuf_write_children_ready(zio_t *zio, arc_buf_t *buf, void *vdb)
4216 dmu_buf_impl_t *db = vdb;
4219 unsigned int epbs, i;
4221 ASSERT3U(db->db_level, >, 0);
4224 epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
4225 ASSERT3U(epbs, <, 31);
4227 /* Determine if all our children are holes */
4228 for (i = 0, bp = db->db.db_data; i < 1ULL << epbs; i++, bp++) {
4229 if (!BP_IS_HOLE(bp))
4234 * If all the children are holes, then zero them all out so that
4235 * we may get compressed away.
4237 if (i == 1ULL << epbs) {
4239 * We only found holes. Grab the rwlock to prevent
4240 * anybody from reading the blocks we're about to
4243 rw_enter(&db->db_rwlock, RW_WRITER);
4244 bzero(db->db.db_data, db->db.db_size);
4245 rw_exit(&db->db_rwlock);
4251 * The SPA will call this callback several times for each zio - once
4252 * for every physical child i/o (zio->io_phys_children times). This
4253 * allows the DMU to monitor the progress of each logical i/o. For example,
4254 * there may be 2 copies of an indirect block, or many fragments of a RAID-Z
4255 * block. There may be a long delay before all copies/fragments are completed,
4256 * so this callback allows us to retire dirty space gradually, as the physical
4261 dbuf_write_physdone(zio_t *zio, arc_buf_t *buf, void *arg)
4263 dmu_buf_impl_t *db = arg;
4264 objset_t *os = db->db_objset;
4265 dsl_pool_t *dp = dmu_objset_pool(os);
4266 dbuf_dirty_record_t *dr;
4269 dr = db->db_data_pending;
4270 ASSERT3U(dr->dr_txg, ==, zio->io_txg);
4273 * The callback will be called io_phys_children times. Retire one
4274 * portion of our dirty space each time we are called. Any rounding
4275 * error will be cleaned up by dbuf_write_done().
4277 delta = dr->dr_accounted / zio->io_phys_children;
4278 dsl_pool_undirty_space(dp, delta, zio->io_txg);
4283 dbuf_write_done(zio_t *zio, arc_buf_t *buf, void *vdb)
4285 dmu_buf_impl_t *db = vdb;
4286 blkptr_t *bp_orig = &zio->io_bp_orig;
4287 blkptr_t *bp = db->db_blkptr;
4288 objset_t *os = db->db_objset;
4289 dmu_tx_t *tx = os->os_synctx;
4290 dbuf_dirty_record_t **drp, *dr;
4292 ASSERT0(zio->io_error);
4293 ASSERT(db->db_blkptr == bp);
4296 * For nopwrites and rewrites we ensure that the bp matches our
4297 * original and bypass all the accounting.
4299 if (zio->io_flags & (ZIO_FLAG_IO_REWRITE | ZIO_FLAG_NOPWRITE)) {
4300 ASSERT(BP_EQUAL(bp, bp_orig));
4302 dsl_dataset_t *ds = os->os_dsl_dataset;
4303 (void) dsl_dataset_block_kill(ds, bp_orig, tx, B_TRUE);
4304 dsl_dataset_block_born(ds, bp, tx);
4307 mutex_enter(&db->db_mtx);
4311 drp = &db->db_last_dirty;
4312 while ((dr = *drp) != db->db_data_pending)
4314 ASSERT(!list_link_active(&dr->dr_dirty_node));
4315 ASSERT(dr->dr_dbuf == db);
4316 ASSERT(dr->dr_next == NULL);
4320 if (db->db_blkid == DMU_SPILL_BLKID) {
4325 ASSERT(dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR);
4326 ASSERT(!(BP_IS_HOLE(db->db_blkptr)) &&
4327 db->db_blkptr == DN_SPILL_BLKPTR(dn->dn_phys));
4332 if (db->db_level == 0) {
4333 ASSERT(db->db_blkid != DMU_BONUS_BLKID);
4334 ASSERT(dr->dt.dl.dr_override_state == DR_NOT_OVERRIDDEN);
4335 if (db->db_state != DB_NOFILL) {
4336 if (dr->dt.dl.dr_data != db->db_buf)
4337 arc_buf_destroy(dr->dt.dl.dr_data, db);
4344 ASSERT(list_head(&dr->dt.di.dr_children) == NULL);
4345 ASSERT3U(db->db.db_size, ==, 1 << dn->dn_phys->dn_indblkshift);
4346 if (!BP_IS_HOLE(db->db_blkptr)) {
4347 int epbs __maybe_unused = dn->dn_phys->dn_indblkshift -
4349 ASSERT3U(db->db_blkid, <=,
4350 dn->dn_phys->dn_maxblkid >> (db->db_level * epbs));
4351 ASSERT3U(BP_GET_LSIZE(db->db_blkptr), ==,
4355 mutex_destroy(&dr->dt.di.dr_mtx);
4356 list_destroy(&dr->dt.di.dr_children);
4359 cv_broadcast(&db->db_changed);
4360 ASSERT(db->db_dirtycnt > 0);
4361 db->db_dirtycnt -= 1;
4362 db->db_data_pending = NULL;
4363 dbuf_rele_and_unlock(db, (void *)(uintptr_t)tx->tx_txg, B_FALSE);
4366 * If we didn't do a physical write in this ZIO and we
4367 * still ended up here, it means that the space of the
4368 * dbuf that we just released (and undirtied) above hasn't
4369 * been marked as undirtied in the pool's accounting.
4371 * Thus, we undirty that space in the pool's view of the
4372 * world here. For physical writes this type of update
4373 * happens in dbuf_write_physdone().
4375 * If we did a physical write, cleanup any rounding errors
4376 * that came up due to writing multiple copies of a block
4377 * on disk [see dbuf_write_physdone()].
4379 if (zio->io_phys_children == 0) {
4380 dsl_pool_undirty_space(dmu_objset_pool(os),
4381 dr->dr_accounted, zio->io_txg);
4383 dsl_pool_undirty_space(dmu_objset_pool(os),
4384 dr->dr_accounted % zio->io_phys_children, zio->io_txg);
4387 kmem_free(dr, sizeof (dbuf_dirty_record_t));
4391 dbuf_write_nofill_ready(zio_t *zio)
4393 dbuf_write_ready(zio, NULL, zio->io_private);
4397 dbuf_write_nofill_done(zio_t *zio)
4399 dbuf_write_done(zio, NULL, zio->io_private);
4403 dbuf_write_override_ready(zio_t *zio)
4405 dbuf_dirty_record_t *dr = zio->io_private;
4406 dmu_buf_impl_t *db = dr->dr_dbuf;
4408 dbuf_write_ready(zio, NULL, db);
4412 dbuf_write_override_done(zio_t *zio)
4414 dbuf_dirty_record_t *dr = zio->io_private;
4415 dmu_buf_impl_t *db = dr->dr_dbuf;
4416 blkptr_t *obp = &dr->dt.dl.dr_overridden_by;
4418 mutex_enter(&db->db_mtx);
4419 if (!BP_EQUAL(zio->io_bp, obp)) {
4420 if (!BP_IS_HOLE(obp))
4421 dsl_free(spa_get_dsl(zio->io_spa), zio->io_txg, obp);
4422 arc_release(dr->dt.dl.dr_data, db);
4424 mutex_exit(&db->db_mtx);
4426 dbuf_write_done(zio, NULL, db);
4428 if (zio->io_abd != NULL)
4429 abd_put(zio->io_abd);
4432 typedef struct dbuf_remap_impl_callback_arg {
4434 uint64_t drica_blk_birth;
4436 } dbuf_remap_impl_callback_arg_t;
4439 dbuf_remap_impl_callback(uint64_t vdev, uint64_t offset, uint64_t size,
4442 dbuf_remap_impl_callback_arg_t *drica = arg;
4443 objset_t *os = drica->drica_os;
4444 spa_t *spa = dmu_objset_spa(os);
4445 dmu_tx_t *tx = drica->drica_tx;
4447 ASSERT(dsl_pool_sync_context(spa_get_dsl(spa)));
4449 if (os == spa_meta_objset(spa)) {
4450 spa_vdev_indirect_mark_obsolete(spa, vdev, offset, size, tx);
4452 dsl_dataset_block_remapped(dmu_objset_ds(os), vdev, offset,
4453 size, drica->drica_blk_birth, tx);
4458 dbuf_remap_impl(dnode_t *dn, blkptr_t *bp, krwlock_t *rw, dmu_tx_t *tx)
4460 blkptr_t bp_copy = *bp;
4461 spa_t *spa = dmu_objset_spa(dn->dn_objset);
4462 dbuf_remap_impl_callback_arg_t drica;
4464 ASSERT(dsl_pool_sync_context(spa_get_dsl(spa)));
4466 drica.drica_os = dn->dn_objset;
4467 drica.drica_blk_birth = bp->blk_birth;
4468 drica.drica_tx = tx;
4469 if (spa_remap_blkptr(spa, &bp_copy, dbuf_remap_impl_callback,
4472 * If the blkptr being remapped is tracked by a livelist,
4473 * then we need to make sure the livelist reflects the update.
4474 * First, cancel out the old blkptr by appending a 'FREE'
4475 * entry. Next, add an 'ALLOC' to track the new version. This
4476 * way we avoid trying to free an inaccurate blkptr at delete.
4477 * Note that embedded blkptrs are not tracked in livelists.
4479 if (dn->dn_objset != spa_meta_objset(spa)) {
4480 dsl_dataset_t *ds = dmu_objset_ds(dn->dn_objset);
4481 if (dsl_deadlist_is_open(&ds->ds_dir->dd_livelist) &&
4482 bp->blk_birth > ds->ds_dir->dd_origin_txg) {
4483 ASSERT(!BP_IS_EMBEDDED(bp));
4484 ASSERT(dsl_dir_is_clone(ds->ds_dir));
4485 ASSERT(spa_feature_is_enabled(spa,
4486 SPA_FEATURE_LIVELIST));
4487 bplist_append(&ds->ds_dir->dd_pending_frees,
4489 bplist_append(&ds->ds_dir->dd_pending_allocs,
4495 * The db_rwlock prevents dbuf_read_impl() from
4496 * dereferencing the BP while we are changing it. To
4497 * avoid lock contention, only grab it when we are actually
4501 rw_enter(rw, RW_WRITER);
4509 * Remap any existing BP's to concrete vdevs, if possible.
4512 dbuf_remap(dnode_t *dn, dmu_buf_impl_t *db, dmu_tx_t *tx)
4514 spa_t *spa = dmu_objset_spa(db->db_objset);
4515 ASSERT(dsl_pool_sync_context(spa_get_dsl(spa)));
4517 if (!spa_feature_is_active(spa, SPA_FEATURE_DEVICE_REMOVAL))
4520 if (db->db_level > 0) {
4521 blkptr_t *bp = db->db.db_data;
4522 for (int i = 0; i < db->db.db_size >> SPA_BLKPTRSHIFT; i++) {
4523 dbuf_remap_impl(dn, &bp[i], &db->db_rwlock, tx);
4525 } else if (db->db.db_object == DMU_META_DNODE_OBJECT) {
4526 dnode_phys_t *dnp = db->db.db_data;
4527 ASSERT3U(db->db_dnode_handle->dnh_dnode->dn_type, ==,
4529 for (int i = 0; i < db->db.db_size >> DNODE_SHIFT;
4530 i += dnp[i].dn_extra_slots + 1) {
4531 for (int j = 0; j < dnp[i].dn_nblkptr; j++) {
4532 krwlock_t *lock = (dn->dn_dbuf == NULL ? NULL :
4533 &dn->dn_dbuf->db_rwlock);
4534 dbuf_remap_impl(dn, &dnp[i].dn_blkptr[j], lock,
4542 /* Issue I/O to commit a dirty buffer to disk. */
4544 dbuf_write(dbuf_dirty_record_t *dr, arc_buf_t *data, dmu_tx_t *tx)
4546 dmu_buf_impl_t *db = dr->dr_dbuf;
4549 dmu_buf_impl_t *parent = db->db_parent;
4550 uint64_t txg = tx->tx_txg;
4551 zbookmark_phys_t zb;
4556 ASSERT(dmu_tx_is_syncing(tx));
4562 if (db->db_state != DB_NOFILL) {
4563 if (db->db_level > 0 || dn->dn_type == DMU_OT_DNODE) {
4565 * Private object buffers are released here rather
4566 * than in dbuf_dirty() since they are only modified
4567 * in the syncing context and we don't want the
4568 * overhead of making multiple copies of the data.
4570 if (BP_IS_HOLE(db->db_blkptr)) {
4573 dbuf_release_bp(db);
4575 dbuf_remap(dn, db, tx);
4579 if (parent != dn->dn_dbuf) {
4580 /* Our parent is an indirect block. */
4581 /* We have a dirty parent that has been scheduled for write. */
4582 ASSERT(parent && parent->db_data_pending);
4583 /* Our parent's buffer is one level closer to the dnode. */
4584 ASSERT(db->db_level == parent->db_level-1);
4586 * We're about to modify our parent's db_data by modifying
4587 * our block pointer, so the parent must be released.
4589 ASSERT(arc_released(parent->db_buf));
4590 zio = parent->db_data_pending->dr_zio;
4592 /* Our parent is the dnode itself. */
4593 ASSERT((db->db_level == dn->dn_phys->dn_nlevels-1 &&
4594 db->db_blkid != DMU_SPILL_BLKID) ||
4595 (db->db_blkid == DMU_SPILL_BLKID && db->db_level == 0));
4596 if (db->db_blkid != DMU_SPILL_BLKID)
4597 ASSERT3P(db->db_blkptr, ==,
4598 &dn->dn_phys->dn_blkptr[db->db_blkid]);
4602 ASSERT(db->db_level == 0 || data == db->db_buf);
4603 ASSERT3U(db->db_blkptr->blk_birth, <=, txg);
4606 SET_BOOKMARK(&zb, os->os_dsl_dataset ?
4607 os->os_dsl_dataset->ds_object : DMU_META_OBJSET,
4608 db->db.db_object, db->db_level, db->db_blkid);
4610 if (db->db_blkid == DMU_SPILL_BLKID)
4612 wp_flag |= (db->db_state == DB_NOFILL) ? WP_NOFILL : 0;
4614 dmu_write_policy(os, dn, db->db_level, wp_flag, &zp);
4618 * We copy the blkptr now (rather than when we instantiate the dirty
4619 * record), because its value can change between open context and
4620 * syncing context. We do not need to hold dn_struct_rwlock to read
4621 * db_blkptr because we are in syncing context.
4623 dr->dr_bp_copy = *db->db_blkptr;
4625 if (db->db_level == 0 &&
4626 dr->dt.dl.dr_override_state == DR_OVERRIDDEN) {
4628 * The BP for this block has been provided by open context
4629 * (by dmu_sync() or dmu_buf_write_embedded()).
4631 abd_t *contents = (data != NULL) ?
4632 abd_get_from_buf(data->b_data, arc_buf_size(data)) : NULL;
4634 dr->dr_zio = zio_write(zio, os->os_spa, txg,
4635 &dr->dr_bp_copy, contents, db->db.db_size, db->db.db_size,
4636 &zp, dbuf_write_override_ready, NULL, NULL,
4637 dbuf_write_override_done,
4638 dr, ZIO_PRIORITY_ASYNC_WRITE, ZIO_FLAG_MUSTSUCCEED, &zb);
4639 mutex_enter(&db->db_mtx);
4640 dr->dt.dl.dr_override_state = DR_NOT_OVERRIDDEN;
4641 zio_write_override(dr->dr_zio, &dr->dt.dl.dr_overridden_by,
4642 dr->dt.dl.dr_copies, dr->dt.dl.dr_nopwrite);
4643 mutex_exit(&db->db_mtx);
4644 } else if (db->db_state == DB_NOFILL) {
4645 ASSERT(zp.zp_checksum == ZIO_CHECKSUM_OFF ||
4646 zp.zp_checksum == ZIO_CHECKSUM_NOPARITY);
4647 dr->dr_zio = zio_write(zio, os->os_spa, txg,
4648 &dr->dr_bp_copy, NULL, db->db.db_size, db->db.db_size, &zp,
4649 dbuf_write_nofill_ready, NULL, NULL,
4650 dbuf_write_nofill_done, db,
4651 ZIO_PRIORITY_ASYNC_WRITE,
4652 ZIO_FLAG_MUSTSUCCEED | ZIO_FLAG_NODATA, &zb);
4654 ASSERT(arc_released(data));
4657 * For indirect blocks, we want to setup the children
4658 * ready callback so that we can properly handle an indirect
4659 * block that only contains holes.
4661 arc_write_done_func_t *children_ready_cb = NULL;
4662 if (db->db_level != 0)
4663 children_ready_cb = dbuf_write_children_ready;
4665 dr->dr_zio = arc_write(zio, os->os_spa, txg,
4666 &dr->dr_bp_copy, data, DBUF_IS_L2CACHEABLE(db),
4667 &zp, dbuf_write_ready,
4668 children_ready_cb, dbuf_write_physdone,
4669 dbuf_write_done, db, ZIO_PRIORITY_ASYNC_WRITE,
4670 ZIO_FLAG_MUSTSUCCEED, &zb);
4674 EXPORT_SYMBOL(dbuf_find);
4675 EXPORT_SYMBOL(dbuf_is_metadata);
4676 EXPORT_SYMBOL(dbuf_destroy);
4677 EXPORT_SYMBOL(dbuf_loan_arcbuf);
4678 EXPORT_SYMBOL(dbuf_whichblock);
4679 EXPORT_SYMBOL(dbuf_read);
4680 EXPORT_SYMBOL(dbuf_unoverride);
4681 EXPORT_SYMBOL(dbuf_free_range);
4682 EXPORT_SYMBOL(dbuf_new_size);
4683 EXPORT_SYMBOL(dbuf_release_bp);
4684 EXPORT_SYMBOL(dbuf_dirty);
4685 EXPORT_SYMBOL(dmu_buf_set_crypt_params);
4686 EXPORT_SYMBOL(dmu_buf_will_dirty);
4687 EXPORT_SYMBOL(dmu_buf_is_dirty);
4688 EXPORT_SYMBOL(dmu_buf_will_not_fill);
4689 EXPORT_SYMBOL(dmu_buf_will_fill);
4690 EXPORT_SYMBOL(dmu_buf_fill_done);
4691 EXPORT_SYMBOL(dmu_buf_rele);
4692 EXPORT_SYMBOL(dbuf_assign_arcbuf);
4693 EXPORT_SYMBOL(dbuf_prefetch);
4694 EXPORT_SYMBOL(dbuf_hold_impl);
4695 EXPORT_SYMBOL(dbuf_hold);
4696 EXPORT_SYMBOL(dbuf_hold_level);
4697 EXPORT_SYMBOL(dbuf_create_bonus);
4698 EXPORT_SYMBOL(dbuf_spill_set_blksz);
4699 EXPORT_SYMBOL(dbuf_rm_spill);
4700 EXPORT_SYMBOL(dbuf_add_ref);
4701 EXPORT_SYMBOL(dbuf_rele);
4702 EXPORT_SYMBOL(dbuf_rele_and_unlock);
4703 EXPORT_SYMBOL(dbuf_refcount);
4704 EXPORT_SYMBOL(dbuf_sync_list);
4705 EXPORT_SYMBOL(dmu_buf_set_user);
4706 EXPORT_SYMBOL(dmu_buf_set_user_ie);
4707 EXPORT_SYMBOL(dmu_buf_get_user);
4708 EXPORT_SYMBOL(dmu_buf_get_blkptr);
4711 ZFS_MODULE_PARAM(zfs_dbuf_cache, dbuf_cache_, max_bytes, ULONG, ZMOD_RW,
4712 "Maximum size in bytes of the dbuf cache.");
4714 ZFS_MODULE_PARAM(zfs_dbuf_cache, dbuf_cache_, hiwater_pct, UINT, ZMOD_RW,
4715 "Percentage over dbuf_cache_max_bytes when dbufs must be evicted "
4718 ZFS_MODULE_PARAM(zfs_dbuf_cache, dbuf_cache_, lowater_pct, UINT, ZMOD_RW,
4719 "Percentage below dbuf_cache_max_bytes when the evict thread stops "
4722 ZFS_MODULE_PARAM(zfs_dbuf, dbuf_, metadata_cache_max_bytes, ULONG, ZMOD_RW,
4723 "Maximum size in bytes of the dbuf metadata cache.");
4725 ZFS_MODULE_PARAM(zfs_dbuf, dbuf_, cache_shift, INT, ZMOD_RW,
4726 "Set the size of the dbuf cache to a log2 fraction of arc size.");
4728 ZFS_MODULE_PARAM(zfs_dbuf, dbuf_, metadata_cache_shift, INT, ZMOD_RW,
4729 "Set the size of the dbuf metadata cache to a log2 fraction of arc "