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, 2020 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.
27 * Copyright (c) 2019, Klara Inc.
28 * Copyright (c) 2019, Allan Jude
31 #include <sys/zfs_context.h>
34 #include <sys/dmu_send.h>
35 #include <sys/dmu_impl.h>
37 #include <sys/dmu_objset.h>
38 #include <sys/dsl_dataset.h>
39 #include <sys/dsl_dir.h>
40 #include <sys/dmu_tx.h>
43 #include <sys/dmu_zfetch.h>
45 #include <sys/sa_impl.h>
46 #include <sys/zfeature.h>
47 #include <sys/blkptr.h>
48 #include <sys/range_tree.h>
49 #include <sys/trace_zfs.h>
50 #include <sys/callb.h>
54 #include <sys/spa_impl.h>
58 typedef struct dbuf_stats
{
60 * Various statistics about the size of the dbuf cache.
62 kstat_named_t cache_count
;
63 kstat_named_t cache_size_bytes
;
64 kstat_named_t cache_size_bytes_max
;
66 * Statistics regarding the bounds on the dbuf cache size.
68 kstat_named_t cache_target_bytes
;
69 kstat_named_t cache_lowater_bytes
;
70 kstat_named_t cache_hiwater_bytes
;
72 * Total number of dbuf cache evictions that have occurred.
74 kstat_named_t cache_total_evicts
;
76 * The distribution of dbuf levels in the dbuf cache and
77 * the total size of all dbufs at each level.
79 kstat_named_t cache_levels
[DN_MAX_LEVELS
];
80 kstat_named_t cache_levels_bytes
[DN_MAX_LEVELS
];
82 * Statistics about the dbuf hash table.
84 kstat_named_t hash_hits
;
85 kstat_named_t hash_misses
;
86 kstat_named_t hash_collisions
;
87 kstat_named_t hash_elements
;
88 kstat_named_t hash_elements_max
;
90 * Number of sublists containing more than one dbuf in the dbuf
91 * hash table. Keep track of the longest hash chain.
93 kstat_named_t hash_chains
;
94 kstat_named_t hash_chain_max
;
96 * Number of times a dbuf_create() discovers that a dbuf was
97 * already created and in the dbuf hash table.
99 kstat_named_t hash_insert_race
;
101 * Statistics about the size of the metadata dbuf cache.
103 kstat_named_t metadata_cache_count
;
104 kstat_named_t metadata_cache_size_bytes
;
105 kstat_named_t metadata_cache_size_bytes_max
;
107 * For diagnostic purposes, this is incremented whenever we can't add
108 * something to the metadata cache because it's full, and instead put
109 * the data in the regular dbuf cache.
111 kstat_named_t metadata_cache_overflow
;
114 dbuf_stats_t dbuf_stats
= {
115 { "cache_count", KSTAT_DATA_UINT64
},
116 { "cache_size_bytes", KSTAT_DATA_UINT64
},
117 { "cache_size_bytes_max", KSTAT_DATA_UINT64
},
118 { "cache_target_bytes", KSTAT_DATA_UINT64
},
119 { "cache_lowater_bytes", KSTAT_DATA_UINT64
},
120 { "cache_hiwater_bytes", KSTAT_DATA_UINT64
},
121 { "cache_total_evicts", KSTAT_DATA_UINT64
},
122 { { "cache_levels_N", KSTAT_DATA_UINT64
} },
123 { { "cache_levels_bytes_N", KSTAT_DATA_UINT64
} },
124 { "hash_hits", KSTAT_DATA_UINT64
},
125 { "hash_misses", KSTAT_DATA_UINT64
},
126 { "hash_collisions", KSTAT_DATA_UINT64
},
127 { "hash_elements", KSTAT_DATA_UINT64
},
128 { "hash_elements_max", KSTAT_DATA_UINT64
},
129 { "hash_chains", KSTAT_DATA_UINT64
},
130 { "hash_chain_max", KSTAT_DATA_UINT64
},
131 { "hash_insert_race", KSTAT_DATA_UINT64
},
132 { "metadata_cache_count", KSTAT_DATA_UINT64
},
133 { "metadata_cache_size_bytes", KSTAT_DATA_UINT64
},
134 { "metadata_cache_size_bytes_max", KSTAT_DATA_UINT64
},
135 { "metadata_cache_overflow", KSTAT_DATA_UINT64
}
138 #define DBUF_STAT_INCR(stat, val) \
139 atomic_add_64(&dbuf_stats.stat.value.ui64, (val));
140 #define DBUF_STAT_DECR(stat, val) \
141 DBUF_STAT_INCR(stat, -(val));
142 #define DBUF_STAT_BUMP(stat) \
143 DBUF_STAT_INCR(stat, 1);
144 #define DBUF_STAT_BUMPDOWN(stat) \
145 DBUF_STAT_INCR(stat, -1);
146 #define DBUF_STAT_MAX(stat, v) { \
148 while ((v) > (_m = dbuf_stats.stat.value.ui64) && \
149 (_m != atomic_cas_64(&dbuf_stats.stat.value.ui64, _m, (v))))\
153 static boolean_t
dbuf_undirty(dmu_buf_impl_t
*db
, dmu_tx_t
*tx
);
154 static void dbuf_write(dbuf_dirty_record_t
*dr
, arc_buf_t
*data
, dmu_tx_t
*tx
);
155 static void dbuf_sync_leaf_verify_bonus_dnode(dbuf_dirty_record_t
*dr
);
156 static int dbuf_read_verify_dnode_crypt(dmu_buf_impl_t
*db
, uint32_t flags
);
158 extern inline void dmu_buf_init_user(dmu_buf_user_t
*dbu
,
159 dmu_buf_evict_func_t
*evict_func_sync
,
160 dmu_buf_evict_func_t
*evict_func_async
,
161 dmu_buf_t
**clear_on_evict_dbufp
);
164 * Global data structures and functions for the dbuf cache.
166 static kmem_cache_t
*dbuf_kmem_cache
;
167 static taskq_t
*dbu_evict_taskq
;
169 static kthread_t
*dbuf_cache_evict_thread
;
170 static kmutex_t dbuf_evict_lock
;
171 static kcondvar_t dbuf_evict_cv
;
172 static boolean_t dbuf_evict_thread_exit
;
175 * There are two dbuf caches; each dbuf can only be in one of them at a time.
177 * 1. Cache of metadata dbufs, to help make read-heavy administrative commands
178 * from /sbin/zfs run faster. The "metadata cache" specifically stores dbufs
179 * that represent the metadata that describes filesystems/snapshots/
180 * bookmarks/properties/etc. We only evict from this cache when we export a
181 * pool, to short-circuit as much I/O as possible for all administrative
182 * commands that need the metadata. There is no eviction policy for this
183 * cache, because we try to only include types in it which would occupy a
184 * very small amount of space per object but create a large impact on the
185 * performance of these commands. Instead, after it reaches a maximum size
186 * (which should only happen on very small memory systems with a very large
187 * number of filesystem objects), we stop taking new dbufs into the
188 * metadata cache, instead putting them in the normal dbuf cache.
190 * 2. LRU cache of dbufs. The dbuf cache maintains a list of dbufs that
191 * are not currently held but have been recently released. These dbufs
192 * are not eligible for arc eviction until they are aged out of the cache.
193 * Dbufs that are aged out of the cache will be immediately destroyed and
194 * become eligible for arc eviction.
196 * Dbufs are added to these caches once the last hold is released. If a dbuf is
197 * later accessed and still exists in the dbuf cache, then it will be removed
198 * from the cache and later re-added to the head of the cache.
200 * If a given dbuf meets the requirements for the metadata cache, it will go
201 * there, otherwise it will be considered for the generic LRU dbuf cache. The
202 * caches and the refcounts tracking their sizes are stored in an array indexed
203 * by those caches' matching enum values (from dbuf_cached_state_t).
205 typedef struct dbuf_cache
{
209 dbuf_cache_t dbuf_caches
[DB_CACHE_MAX
];
211 /* Size limits for the caches */
212 unsigned long dbuf_cache_max_bytes
= ULONG_MAX
;
213 unsigned long dbuf_metadata_cache_max_bytes
= ULONG_MAX
;
215 /* Set the default sizes of the caches to log2 fraction of arc size */
216 int dbuf_cache_shift
= 5;
217 int dbuf_metadata_cache_shift
= 6;
219 static unsigned long dbuf_cache_target_bytes(void);
220 static unsigned long dbuf_metadata_cache_target_bytes(void);
223 * The LRU dbuf cache uses a three-stage eviction policy:
224 * - A low water marker designates when the dbuf eviction thread
225 * should stop evicting from the dbuf cache.
226 * - When we reach the maximum size (aka mid water mark), we
227 * signal the eviction thread to run.
228 * - The high water mark indicates when the eviction thread
229 * is unable to keep up with the incoming load and eviction must
230 * happen in the context of the calling thread.
234 * low water mid water hi water
235 * +----------------------------------------+----------+----------+
240 * +----------------------------------------+----------+----------+
242 * evicting eviction directly
245 * The high and low water marks indicate the operating range for the eviction
246 * thread. The low water mark is, by default, 90% of the total size of the
247 * cache and the high water mark is at 110% (both of these percentages can be
248 * changed by setting dbuf_cache_lowater_pct and dbuf_cache_hiwater_pct,
249 * respectively). The eviction thread will try to ensure that the cache remains
250 * within this range by waking up every second and checking if the cache is
251 * above the low water mark. The thread can also be woken up by callers adding
252 * elements into the cache if the cache is larger than the mid water (i.e max
253 * cache size). Once the eviction thread is woken up and eviction is required,
254 * it will continue evicting buffers until it's able to reduce the cache size
255 * to the low water mark. If the cache size continues to grow and hits the high
256 * water mark, then callers adding elements to the cache will begin to evict
257 * directly from the cache until the cache is no longer above the high water
262 * The percentage above and below the maximum cache size.
264 uint_t dbuf_cache_hiwater_pct
= 10;
265 uint_t dbuf_cache_lowater_pct
= 10;
269 dbuf_cons(void *vdb
, void *unused
, int kmflag
)
271 dmu_buf_impl_t
*db
= vdb
;
272 bzero(db
, sizeof (dmu_buf_impl_t
));
274 mutex_init(&db
->db_mtx
, NULL
, MUTEX_DEFAULT
, NULL
);
275 rw_init(&db
->db_rwlock
, NULL
, RW_DEFAULT
, NULL
);
276 cv_init(&db
->db_changed
, NULL
, CV_DEFAULT
, NULL
);
277 multilist_link_init(&db
->db_cache_link
);
278 zfs_refcount_create(&db
->db_holds
);
285 dbuf_dest(void *vdb
, void *unused
)
287 dmu_buf_impl_t
*db
= vdb
;
288 mutex_destroy(&db
->db_mtx
);
289 rw_destroy(&db
->db_rwlock
);
290 cv_destroy(&db
->db_changed
);
291 ASSERT(!multilist_link_active(&db
->db_cache_link
));
292 zfs_refcount_destroy(&db
->db_holds
);
296 * dbuf hash table routines
298 static dbuf_hash_table_t dbuf_hash_table
;
300 static uint64_t dbuf_hash_count
;
303 * We use Cityhash for this. It's fast, and has good hash properties without
304 * requiring any large static buffers.
307 dbuf_hash(void *os
, uint64_t obj
, uint8_t lvl
, uint64_t blkid
)
309 return (cityhash4((uintptr_t)os
, obj
, (uint64_t)lvl
, blkid
));
312 #define DTRACE_SET_STATE(db, why) \
313 DTRACE_PROBE2(dbuf__state_change, dmu_buf_impl_t *, db, \
316 #define DBUF_EQUAL(dbuf, os, obj, level, blkid) \
317 ((dbuf)->db.db_object == (obj) && \
318 (dbuf)->db_objset == (os) && \
319 (dbuf)->db_level == (level) && \
320 (dbuf)->db_blkid == (blkid))
323 dbuf_find(objset_t
*os
, uint64_t obj
, uint8_t level
, uint64_t blkid
)
325 dbuf_hash_table_t
*h
= &dbuf_hash_table
;
330 hv
= dbuf_hash(os
, obj
, level
, blkid
);
331 idx
= hv
& h
->hash_table_mask
;
333 mutex_enter(DBUF_HASH_MUTEX(h
, idx
));
334 for (db
= h
->hash_table
[idx
]; db
!= NULL
; db
= db
->db_hash_next
) {
335 if (DBUF_EQUAL(db
, os
, obj
, level
, blkid
)) {
336 mutex_enter(&db
->db_mtx
);
337 if (db
->db_state
!= DB_EVICTING
) {
338 mutex_exit(DBUF_HASH_MUTEX(h
, idx
));
341 mutex_exit(&db
->db_mtx
);
344 mutex_exit(DBUF_HASH_MUTEX(h
, idx
));
348 static dmu_buf_impl_t
*
349 dbuf_find_bonus(objset_t
*os
, uint64_t object
)
352 dmu_buf_impl_t
*db
= NULL
;
354 if (dnode_hold(os
, object
, FTAG
, &dn
) == 0) {
355 rw_enter(&dn
->dn_struct_rwlock
, RW_READER
);
356 if (dn
->dn_bonus
!= NULL
) {
358 mutex_enter(&db
->db_mtx
);
360 rw_exit(&dn
->dn_struct_rwlock
);
361 dnode_rele(dn
, FTAG
);
367 * Insert an entry into the hash table. If there is already an element
368 * equal to elem in the hash table, then the already existing element
369 * will be returned and the new element will not be inserted.
370 * Otherwise returns NULL.
372 static dmu_buf_impl_t
*
373 dbuf_hash_insert(dmu_buf_impl_t
*db
)
375 dbuf_hash_table_t
*h
= &dbuf_hash_table
;
376 objset_t
*os
= db
->db_objset
;
377 uint64_t obj
= db
->db
.db_object
;
378 int level
= db
->db_level
;
379 uint64_t blkid
, hv
, idx
;
383 blkid
= db
->db_blkid
;
384 hv
= dbuf_hash(os
, obj
, level
, blkid
);
385 idx
= hv
& h
->hash_table_mask
;
387 mutex_enter(DBUF_HASH_MUTEX(h
, idx
));
388 for (dbf
= h
->hash_table
[idx
], i
= 0; dbf
!= NULL
;
389 dbf
= dbf
->db_hash_next
, i
++) {
390 if (DBUF_EQUAL(dbf
, os
, obj
, level
, blkid
)) {
391 mutex_enter(&dbf
->db_mtx
);
392 if (dbf
->db_state
!= DB_EVICTING
) {
393 mutex_exit(DBUF_HASH_MUTEX(h
, idx
));
396 mutex_exit(&dbf
->db_mtx
);
401 DBUF_STAT_BUMP(hash_collisions
);
403 DBUF_STAT_BUMP(hash_chains
);
405 DBUF_STAT_MAX(hash_chain_max
, i
);
408 mutex_enter(&db
->db_mtx
);
409 db
->db_hash_next
= h
->hash_table
[idx
];
410 h
->hash_table
[idx
] = db
;
411 mutex_exit(DBUF_HASH_MUTEX(h
, idx
));
412 atomic_inc_64(&dbuf_hash_count
);
413 DBUF_STAT_MAX(hash_elements_max
, dbuf_hash_count
);
419 * This returns whether this dbuf should be stored in the metadata cache, which
420 * is based on whether it's from one of the dnode types that store data related
421 * to traversing dataset hierarchies.
424 dbuf_include_in_metadata_cache(dmu_buf_impl_t
*db
)
427 dmu_object_type_t type
= DB_DNODE(db
)->dn_type
;
430 /* Check if this dbuf is one of the types we care about */
431 if (DMU_OT_IS_METADATA_CACHED(type
)) {
432 /* If we hit this, then we set something up wrong in dmu_ot */
433 ASSERT(DMU_OT_IS_METADATA(type
));
436 * Sanity check for small-memory systems: don't allocate too
437 * much memory for this purpose.
439 if (zfs_refcount_count(
440 &dbuf_caches
[DB_DBUF_METADATA_CACHE
].size
) >
441 dbuf_metadata_cache_target_bytes()) {
442 DBUF_STAT_BUMP(metadata_cache_overflow
);
453 * Remove an entry from the hash table. It must be in the EVICTING state.
456 dbuf_hash_remove(dmu_buf_impl_t
*db
)
458 dbuf_hash_table_t
*h
= &dbuf_hash_table
;
460 dmu_buf_impl_t
*dbf
, **dbp
;
462 hv
= dbuf_hash(db
->db_objset
, db
->db
.db_object
,
463 db
->db_level
, db
->db_blkid
);
464 idx
= hv
& h
->hash_table_mask
;
467 * We mustn't hold db_mtx to maintain lock ordering:
468 * DBUF_HASH_MUTEX > db_mtx.
470 ASSERT(zfs_refcount_is_zero(&db
->db_holds
));
471 ASSERT(db
->db_state
== DB_EVICTING
);
472 ASSERT(!MUTEX_HELD(&db
->db_mtx
));
474 mutex_enter(DBUF_HASH_MUTEX(h
, idx
));
475 dbp
= &h
->hash_table
[idx
];
476 while ((dbf
= *dbp
) != db
) {
477 dbp
= &dbf
->db_hash_next
;
480 *dbp
= db
->db_hash_next
;
481 db
->db_hash_next
= NULL
;
482 if (h
->hash_table
[idx
] &&
483 h
->hash_table
[idx
]->db_hash_next
== NULL
)
484 DBUF_STAT_BUMPDOWN(hash_chains
);
485 mutex_exit(DBUF_HASH_MUTEX(h
, idx
));
486 atomic_dec_64(&dbuf_hash_count
);
492 } dbvu_verify_type_t
;
495 dbuf_verify_user(dmu_buf_impl_t
*db
, dbvu_verify_type_t verify_type
)
500 if (db
->db_user
== NULL
)
503 /* Only data blocks support the attachment of user data. */
504 ASSERT(db
->db_level
== 0);
506 /* Clients must resolve a dbuf before attaching user data. */
507 ASSERT(db
->db
.db_data
!= NULL
);
508 ASSERT3U(db
->db_state
, ==, DB_CACHED
);
510 holds
= zfs_refcount_count(&db
->db_holds
);
511 if (verify_type
== DBVU_EVICTING
) {
513 * Immediate eviction occurs when holds == dirtycnt.
514 * For normal eviction buffers, holds is zero on
515 * eviction, except when dbuf_fix_old_data() calls
516 * dbuf_clear_data(). However, the hold count can grow
517 * during eviction even though db_mtx is held (see
518 * dmu_bonus_hold() for an example), so we can only
519 * test the generic invariant that holds >= dirtycnt.
521 ASSERT3U(holds
, >=, db
->db_dirtycnt
);
523 if (db
->db_user_immediate_evict
== TRUE
)
524 ASSERT3U(holds
, >=, db
->db_dirtycnt
);
526 ASSERT3U(holds
, >, 0);
532 dbuf_evict_user(dmu_buf_impl_t
*db
)
534 dmu_buf_user_t
*dbu
= db
->db_user
;
536 ASSERT(MUTEX_HELD(&db
->db_mtx
));
541 dbuf_verify_user(db
, DBVU_EVICTING
);
545 if (dbu
->dbu_clear_on_evict_dbufp
!= NULL
)
546 *dbu
->dbu_clear_on_evict_dbufp
= NULL
;
550 * There are two eviction callbacks - one that we call synchronously
551 * and one that we invoke via a taskq. The async one is useful for
552 * avoiding lock order reversals and limiting stack depth.
554 * Note that if we have a sync callback but no async callback,
555 * it's likely that the sync callback will free the structure
556 * containing the dbu. In that case we need to take care to not
557 * dereference dbu after calling the sync evict func.
559 boolean_t has_async
= (dbu
->dbu_evict_func_async
!= NULL
);
561 if (dbu
->dbu_evict_func_sync
!= NULL
)
562 dbu
->dbu_evict_func_sync(dbu
);
565 taskq_dispatch_ent(dbu_evict_taskq
, dbu
->dbu_evict_func_async
,
566 dbu
, 0, &dbu
->dbu_tqent
);
571 dbuf_is_metadata(dmu_buf_impl_t
*db
)
574 * Consider indirect blocks and spill blocks to be meta data.
576 if (db
->db_level
> 0 || db
->db_blkid
== DMU_SPILL_BLKID
) {
579 boolean_t is_metadata
;
582 is_metadata
= DMU_OT_IS_METADATA(DB_DNODE(db
)->dn_type
);
585 return (is_metadata
);
591 * This function *must* return indices evenly distributed between all
592 * sublists of the multilist. This is needed due to how the dbuf eviction
593 * code is laid out; dbuf_evict_thread() assumes dbufs are evenly
594 * distributed between all sublists and uses this assumption when
595 * deciding which sublist to evict from and how much to evict from it.
598 dbuf_cache_multilist_index_func(multilist_t
*ml
, void *obj
)
600 dmu_buf_impl_t
*db
= obj
;
603 * The assumption here, is the hash value for a given
604 * dmu_buf_impl_t will remain constant throughout it's lifetime
605 * (i.e. it's objset, object, level and blkid fields don't change).
606 * Thus, we don't need to store the dbuf's sublist index
607 * on insertion, as this index can be recalculated on removal.
609 * Also, the low order bits of the hash value are thought to be
610 * distributed evenly. Otherwise, in the case that the multilist
611 * has a power of two number of sublists, each sublists' usage
612 * would not be evenly distributed.
614 return (dbuf_hash(db
->db_objset
, db
->db
.db_object
,
615 db
->db_level
, db
->db_blkid
) %
616 multilist_get_num_sublists(ml
));
620 * The target size of the dbuf cache can grow with the ARC target,
621 * unless limited by the tunable dbuf_cache_max_bytes.
623 static inline unsigned long
624 dbuf_cache_target_bytes(void)
626 return (MIN(dbuf_cache_max_bytes
,
627 arc_target_bytes() >> dbuf_cache_shift
));
631 * The target size of the dbuf metadata cache can grow with the ARC target,
632 * unless limited by the tunable dbuf_metadata_cache_max_bytes.
634 static inline unsigned long
635 dbuf_metadata_cache_target_bytes(void)
637 return (MIN(dbuf_metadata_cache_max_bytes
,
638 arc_target_bytes() >> dbuf_metadata_cache_shift
));
641 static inline uint64_t
642 dbuf_cache_hiwater_bytes(void)
644 uint64_t dbuf_cache_target
= dbuf_cache_target_bytes();
645 return (dbuf_cache_target
+
646 (dbuf_cache_target
* dbuf_cache_hiwater_pct
) / 100);
649 static inline uint64_t
650 dbuf_cache_lowater_bytes(void)
652 uint64_t dbuf_cache_target
= dbuf_cache_target_bytes();
653 return (dbuf_cache_target
-
654 (dbuf_cache_target
* dbuf_cache_lowater_pct
) / 100);
657 static inline boolean_t
658 dbuf_cache_above_lowater(void)
660 return (zfs_refcount_count(&dbuf_caches
[DB_DBUF_CACHE
].size
) >
661 dbuf_cache_lowater_bytes());
665 * Evict the oldest eligible dbuf from the dbuf cache.
670 int idx
= multilist_get_random_index(dbuf_caches
[DB_DBUF_CACHE
].cache
);
671 multilist_sublist_t
*mls
= multilist_sublist_lock(
672 dbuf_caches
[DB_DBUF_CACHE
].cache
, idx
);
674 ASSERT(!MUTEX_HELD(&dbuf_evict_lock
));
676 dmu_buf_impl_t
*db
= multilist_sublist_tail(mls
);
677 while (db
!= NULL
&& mutex_tryenter(&db
->db_mtx
) == 0) {
678 db
= multilist_sublist_prev(mls
, db
);
681 DTRACE_PROBE2(dbuf__evict__one
, dmu_buf_impl_t
*, db
,
682 multilist_sublist_t
*, mls
);
685 multilist_sublist_remove(mls
, db
);
686 multilist_sublist_unlock(mls
);
687 (void) zfs_refcount_remove_many(
688 &dbuf_caches
[DB_DBUF_CACHE
].size
, db
->db
.db_size
, db
);
689 DBUF_STAT_BUMPDOWN(cache_levels
[db
->db_level
]);
690 DBUF_STAT_BUMPDOWN(cache_count
);
691 DBUF_STAT_DECR(cache_levels_bytes
[db
->db_level
],
693 ASSERT3U(db
->db_caching_status
, ==, DB_DBUF_CACHE
);
694 db
->db_caching_status
= DB_NO_CACHE
;
696 DBUF_STAT_BUMP(cache_total_evicts
);
698 multilist_sublist_unlock(mls
);
703 * The dbuf evict thread is responsible for aging out dbufs from the
704 * cache. Once the cache has reached it's maximum size, dbufs are removed
705 * and destroyed. The eviction thread will continue running until the size
706 * of the dbuf cache is at or below the maximum size. Once the dbuf is aged
707 * out of the cache it is destroyed and becomes eligible for arc eviction.
711 dbuf_evict_thread(void *unused
)
715 CALLB_CPR_INIT(&cpr
, &dbuf_evict_lock
, callb_generic_cpr
, FTAG
);
717 mutex_enter(&dbuf_evict_lock
);
718 while (!dbuf_evict_thread_exit
) {
719 while (!dbuf_cache_above_lowater() && !dbuf_evict_thread_exit
) {
720 CALLB_CPR_SAFE_BEGIN(&cpr
);
721 (void) cv_timedwait_idle_hires(&dbuf_evict_cv
,
722 &dbuf_evict_lock
, SEC2NSEC(1), MSEC2NSEC(1), 0);
723 CALLB_CPR_SAFE_END(&cpr
, &dbuf_evict_lock
);
725 mutex_exit(&dbuf_evict_lock
);
728 * Keep evicting as long as we're above the low water mark
729 * for the cache. We do this without holding the locks to
730 * minimize lock contention.
732 while (dbuf_cache_above_lowater() && !dbuf_evict_thread_exit
) {
736 mutex_enter(&dbuf_evict_lock
);
739 dbuf_evict_thread_exit
= B_FALSE
;
740 cv_broadcast(&dbuf_evict_cv
);
741 CALLB_CPR_EXIT(&cpr
); /* drops dbuf_evict_lock */
746 * Wake up the dbuf eviction thread if the dbuf cache is at its max size.
747 * If the dbuf cache is at its high water mark, then evict a dbuf from the
748 * dbuf cache using the callers context.
751 dbuf_evict_notify(uint64_t size
)
754 * We check if we should evict without holding the dbuf_evict_lock,
755 * because it's OK to occasionally make the wrong decision here,
756 * and grabbing the lock results in massive lock contention.
758 if (size
> dbuf_cache_target_bytes()) {
759 if (size
> dbuf_cache_hiwater_bytes())
761 cv_signal(&dbuf_evict_cv
);
766 dbuf_kstat_update(kstat_t
*ksp
, int rw
)
768 dbuf_stats_t
*ds
= ksp
->ks_data
;
770 if (rw
== KSTAT_WRITE
) {
771 return (SET_ERROR(EACCES
));
773 ds
->metadata_cache_size_bytes
.value
.ui64
= zfs_refcount_count(
774 &dbuf_caches
[DB_DBUF_METADATA_CACHE
].size
);
775 ds
->cache_size_bytes
.value
.ui64
=
776 zfs_refcount_count(&dbuf_caches
[DB_DBUF_CACHE
].size
);
777 ds
->cache_target_bytes
.value
.ui64
= dbuf_cache_target_bytes();
778 ds
->cache_hiwater_bytes
.value
.ui64
= dbuf_cache_hiwater_bytes();
779 ds
->cache_lowater_bytes
.value
.ui64
= dbuf_cache_lowater_bytes();
780 ds
->hash_elements
.value
.ui64
= dbuf_hash_count
;
789 uint64_t hsize
= 1ULL << 16;
790 dbuf_hash_table_t
*h
= &dbuf_hash_table
;
794 * The hash table is big enough to fill all of physical memory
795 * with an average block size of zfs_arc_average_blocksize (default 8K).
796 * By default, the table will take up
797 * totalmem * sizeof(void*) / 8K (1MB per GB with 8-byte pointers).
799 while (hsize
* zfs_arc_average_blocksize
< physmem
* PAGESIZE
)
803 h
->hash_table_mask
= hsize
- 1;
806 * Large allocations which do not require contiguous pages
807 * should be using vmem_alloc() in the linux kernel
809 h
->hash_table
= vmem_zalloc(hsize
* sizeof (void *), KM_SLEEP
);
811 h
->hash_table
= kmem_zalloc(hsize
* sizeof (void *), KM_NOSLEEP
);
813 if (h
->hash_table
== NULL
) {
814 /* XXX - we should really return an error instead of assert */
815 ASSERT(hsize
> (1ULL << 10));
820 dbuf_kmem_cache
= kmem_cache_create("dmu_buf_impl_t",
821 sizeof (dmu_buf_impl_t
),
822 0, dbuf_cons
, dbuf_dest
, NULL
, NULL
, NULL
, 0);
824 for (i
= 0; i
< DBUF_MUTEXES
; i
++)
825 mutex_init(&h
->hash_mutexes
[i
], NULL
, MUTEX_DEFAULT
, NULL
);
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
;
925 ASSERT(MUTEX_HELD(&db
->db_mtx
));
927 if (!(zfs_flags
& ZFS_DEBUG_DBUF_VERIFY
))
930 ASSERT(db
->db_objset
!= NULL
);
934 ASSERT(db
->db_parent
== NULL
);
935 ASSERT(db
->db_blkptr
== NULL
);
937 ASSERT3U(db
->db
.db_object
, ==, dn
->dn_object
);
938 ASSERT3P(db
->db_objset
, ==, dn
->dn_objset
);
939 ASSERT3U(db
->db_level
, <, dn
->dn_nlevels
);
940 ASSERT(db
->db_blkid
== DMU_BONUS_BLKID
||
941 db
->db_blkid
== DMU_SPILL_BLKID
||
942 !avl_is_empty(&dn
->dn_dbufs
));
944 if (db
->db_blkid
== DMU_BONUS_BLKID
) {
946 ASSERT3U(db
->db
.db_size
, >=, dn
->dn_bonuslen
);
947 ASSERT3U(db
->db
.db_offset
, ==, DMU_BONUS_BLKID
);
948 } else if (db
->db_blkid
== DMU_SPILL_BLKID
) {
950 ASSERT0(db
->db
.db_offset
);
952 ASSERT3U(db
->db
.db_offset
, ==, db
->db_blkid
* db
->db
.db_size
);
955 if ((dr
= list_head(&db
->db_dirty_records
)) != NULL
) {
956 ASSERT(dr
->dr_dbuf
== db
);
957 txg_prev
= dr
->dr_txg
;
958 for (dr
= list_next(&db
->db_dirty_records
, dr
); dr
!= NULL
;
959 dr
= list_next(&db
->db_dirty_records
, dr
)) {
960 ASSERT(dr
->dr_dbuf
== db
);
961 ASSERT(txg_prev
> dr
->dr_txg
);
962 txg_prev
= dr
->dr_txg
;
967 * We can't assert that db_size matches dn_datablksz because it
968 * can be momentarily different when another thread is doing
971 if (db
->db_level
== 0 && db
->db
.db_object
== DMU_META_DNODE_OBJECT
) {
972 dr
= db
->db_data_pending
;
974 * It should only be modified in syncing context, so
975 * make sure we only have one copy of the data.
977 ASSERT(dr
== NULL
|| dr
->dt
.dl
.dr_data
== db
->db_buf
);
980 /* verify db->db_blkptr */
982 if (db
->db_parent
== dn
->dn_dbuf
) {
983 /* db is pointed to by the dnode */
984 /* ASSERT3U(db->db_blkid, <, dn->dn_nblkptr); */
985 if (DMU_OBJECT_IS_SPECIAL(db
->db
.db_object
))
986 ASSERT(db
->db_parent
== NULL
);
988 ASSERT(db
->db_parent
!= NULL
);
989 if (db
->db_blkid
!= DMU_SPILL_BLKID
)
990 ASSERT3P(db
->db_blkptr
, ==,
991 &dn
->dn_phys
->dn_blkptr
[db
->db_blkid
]);
993 /* db is pointed to by an indirect block */
994 int epb __maybe_unused
= db
->db_parent
->db
.db_size
>>
996 ASSERT3U(db
->db_parent
->db_level
, ==, db
->db_level
+1);
997 ASSERT3U(db
->db_parent
->db
.db_object
, ==,
1000 * dnode_grow_indblksz() can make this fail if we don't
1001 * have the parent's rwlock. XXX indblksz no longer
1002 * grows. safe to do this now?
1004 if (RW_LOCK_HELD(&db
->db_parent
->db_rwlock
)) {
1005 ASSERT3P(db
->db_blkptr
, ==,
1006 ((blkptr_t
*)db
->db_parent
->db
.db_data
+
1007 db
->db_blkid
% epb
));
1011 if ((db
->db_blkptr
== NULL
|| BP_IS_HOLE(db
->db_blkptr
)) &&
1012 (db
->db_buf
== NULL
|| db
->db_buf
->b_data
) &&
1013 db
->db
.db_data
&& db
->db_blkid
!= DMU_BONUS_BLKID
&&
1014 db
->db_state
!= DB_FILL
&& !dn
->dn_free_txg
) {
1016 * If the blkptr isn't set but they have nonzero data,
1017 * it had better be dirty, otherwise we'll lose that
1018 * data when we evict this buffer.
1020 * There is an exception to this rule for indirect blocks; in
1021 * this case, if the indirect block is a hole, we fill in a few
1022 * fields on each of the child blocks (importantly, birth time)
1023 * to prevent hole birth times from being lost when you
1024 * partially fill in a hole.
1026 if (db
->db_dirtycnt
== 0) {
1027 if (db
->db_level
== 0) {
1028 uint64_t *buf
= db
->db
.db_data
;
1031 for (i
= 0; i
< db
->db
.db_size
>> 3; i
++) {
1032 ASSERT(buf
[i
] == 0);
1035 blkptr_t
*bps
= db
->db
.db_data
;
1036 ASSERT3U(1 << DB_DNODE(db
)->dn_indblkshift
, ==,
1039 * We want to verify that all the blkptrs in the
1040 * indirect block are holes, but we may have
1041 * automatically set up a few fields for them.
1042 * We iterate through each blkptr and verify
1043 * they only have those fields set.
1046 i
< db
->db
.db_size
/ sizeof (blkptr_t
);
1048 blkptr_t
*bp
= &bps
[i
];
1049 ASSERT(ZIO_CHECKSUM_IS_ZERO(
1052 DVA_IS_EMPTY(&bp
->blk_dva
[0]) &&
1053 DVA_IS_EMPTY(&bp
->blk_dva
[1]) &&
1054 DVA_IS_EMPTY(&bp
->blk_dva
[2]));
1055 ASSERT0(bp
->blk_fill
);
1056 ASSERT0(bp
->blk_pad
[0]);
1057 ASSERT0(bp
->blk_pad
[1]);
1058 ASSERT(!BP_IS_EMBEDDED(bp
));
1059 ASSERT(BP_IS_HOLE(bp
));
1060 ASSERT0(bp
->blk_phys_birth
);
1070 dbuf_clear_data(dmu_buf_impl_t
*db
)
1072 ASSERT(MUTEX_HELD(&db
->db_mtx
));
1073 dbuf_evict_user(db
);
1074 ASSERT3P(db
->db_buf
, ==, NULL
);
1075 db
->db
.db_data
= NULL
;
1076 if (db
->db_state
!= DB_NOFILL
) {
1077 db
->db_state
= DB_UNCACHED
;
1078 DTRACE_SET_STATE(db
, "clear data");
1083 dbuf_set_data(dmu_buf_impl_t
*db
, arc_buf_t
*buf
)
1085 ASSERT(MUTEX_HELD(&db
->db_mtx
));
1086 ASSERT(buf
!= NULL
);
1089 ASSERT(buf
->b_data
!= NULL
);
1090 db
->db
.db_data
= buf
->b_data
;
1094 dbuf_alloc_arcbuf_from_arcbuf(dmu_buf_impl_t
*db
, arc_buf_t
*data
)
1096 objset_t
*os
= db
->db_objset
;
1097 spa_t
*spa
= os
->os_spa
;
1098 arc_buf_contents_t type
= DBUF_GET_BUFC_TYPE(db
);
1099 enum zio_compress compress_type
;
1103 psize
= arc_buf_size(data
);
1104 lsize
= arc_buf_lsize(data
);
1105 compress_type
= arc_get_compression(data
);
1106 complevel
= arc_get_complevel(data
);
1108 if (arc_is_encrypted(data
)) {
1109 boolean_t byteorder
;
1110 uint8_t salt
[ZIO_DATA_SALT_LEN
];
1111 uint8_t iv
[ZIO_DATA_IV_LEN
];
1112 uint8_t mac
[ZIO_DATA_MAC_LEN
];
1113 dnode_t
*dn
= DB_DNODE(db
);
1115 arc_get_raw_params(data
, &byteorder
, salt
, iv
, mac
);
1116 data
= arc_alloc_raw_buf(spa
, db
, dmu_objset_id(os
),
1117 byteorder
, salt
, iv
, mac
, dn
->dn_type
, psize
, lsize
,
1118 compress_type
, complevel
);
1119 } else if (compress_type
!= ZIO_COMPRESS_OFF
) {
1120 ASSERT3U(type
, ==, ARC_BUFC_DATA
);
1121 data
= arc_alloc_compressed_buf(spa
, db
,
1122 psize
, lsize
, compress_type
, complevel
);
1124 data
= arc_alloc_buf(spa
, db
, type
, psize
);
1130 dbuf_alloc_arcbuf(dmu_buf_impl_t
*db
)
1132 spa_t
*spa
= db
->db_objset
->os_spa
;
1134 return (arc_alloc_buf(spa
, db
, DBUF_GET_BUFC_TYPE(db
), db
->db
.db_size
));
1138 * Loan out an arc_buf for read. Return the loaned arc_buf.
1141 dbuf_loan_arcbuf(dmu_buf_impl_t
*db
)
1145 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
1146 mutex_enter(&db
->db_mtx
);
1147 if (arc_released(db
->db_buf
) || zfs_refcount_count(&db
->db_holds
) > 1) {
1148 int blksz
= db
->db
.db_size
;
1149 spa_t
*spa
= db
->db_objset
->os_spa
;
1151 mutex_exit(&db
->db_mtx
);
1152 abuf
= arc_loan_buf(spa
, B_FALSE
, blksz
);
1153 bcopy(db
->db
.db_data
, abuf
->b_data
, blksz
);
1156 arc_loan_inuse_buf(abuf
, db
);
1158 dbuf_clear_data(db
);
1159 mutex_exit(&db
->db_mtx
);
1165 * Calculate which level n block references the data at the level 0 offset
1169 dbuf_whichblock(const dnode_t
*dn
, const int64_t level
, const uint64_t offset
)
1171 if (dn
->dn_datablkshift
!= 0 && dn
->dn_indblkshift
!= 0) {
1173 * The level n blkid is equal to the level 0 blkid divided by
1174 * the number of level 0s in a level n block.
1176 * The level 0 blkid is offset >> datablkshift =
1177 * offset / 2^datablkshift.
1179 * The number of level 0s in a level n is the number of block
1180 * pointers in an indirect block, raised to the power of level.
1181 * This is 2^(indblkshift - SPA_BLKPTRSHIFT)^level =
1182 * 2^(level*(indblkshift - SPA_BLKPTRSHIFT)).
1184 * Thus, the level n blkid is: offset /
1185 * ((2^datablkshift)*(2^(level*(indblkshift-SPA_BLKPTRSHIFT))))
1186 * = offset / 2^(datablkshift + level *
1187 * (indblkshift - SPA_BLKPTRSHIFT))
1188 * = offset >> (datablkshift + level *
1189 * (indblkshift - SPA_BLKPTRSHIFT))
1192 const unsigned exp
= dn
->dn_datablkshift
+
1193 level
* (dn
->dn_indblkshift
- SPA_BLKPTRSHIFT
);
1195 if (exp
>= 8 * sizeof (offset
)) {
1196 /* This only happens on the highest indirection level */
1197 ASSERT3U(level
, ==, dn
->dn_nlevels
- 1);
1201 ASSERT3U(exp
, <, 8 * sizeof (offset
));
1203 return (offset
>> exp
);
1205 ASSERT3U(offset
, <, dn
->dn_datablksz
);
1211 * This function is used to lock the parent of the provided dbuf. This should be
1212 * used when modifying or reading db_blkptr.
1215 dmu_buf_lock_parent(dmu_buf_impl_t
*db
, krw_t rw
, void *tag
)
1217 enum db_lock_type ret
= DLT_NONE
;
1218 if (db
->db_parent
!= NULL
) {
1219 rw_enter(&db
->db_parent
->db_rwlock
, rw
);
1221 } else if (dmu_objset_ds(db
->db_objset
) != NULL
) {
1222 rrw_enter(&dmu_objset_ds(db
->db_objset
)->ds_bp_rwlock
, rw
,
1227 * We only return a DLT_NONE lock when it's the top-most indirect block
1228 * of the meta-dnode of the MOS.
1234 * We need to pass the lock type in because it's possible that the block will
1235 * move from being the topmost indirect block in a dnode (and thus, have no
1236 * parent) to not the top-most via an indirection increase. This would cause a
1237 * panic if we didn't pass the lock type in.
1240 dmu_buf_unlock_parent(dmu_buf_impl_t
*db
, db_lock_type_t type
, void *tag
)
1242 if (type
== DLT_PARENT
)
1243 rw_exit(&db
->db_parent
->db_rwlock
);
1244 else if (type
== DLT_OBJSET
)
1245 rrw_exit(&dmu_objset_ds(db
->db_objset
)->ds_bp_rwlock
, tag
);
1249 dbuf_read_done(zio_t
*zio
, const zbookmark_phys_t
*zb
, const blkptr_t
*bp
,
1250 arc_buf_t
*buf
, void *vdb
)
1252 dmu_buf_impl_t
*db
= vdb
;
1254 mutex_enter(&db
->db_mtx
);
1255 ASSERT3U(db
->db_state
, ==, DB_READ
);
1257 * All reads are synchronous, so we must have a hold on the dbuf
1259 ASSERT(zfs_refcount_count(&db
->db_holds
) > 0);
1260 ASSERT(db
->db_buf
== NULL
);
1261 ASSERT(db
->db
.db_data
== NULL
);
1264 ASSERT(zio
== NULL
|| zio
->io_error
!= 0);
1265 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
1266 ASSERT3P(db
->db_buf
, ==, NULL
);
1267 db
->db_state
= DB_UNCACHED
;
1268 DTRACE_SET_STATE(db
, "i/o error");
1269 } else if (db
->db_level
== 0 && db
->db_freed_in_flight
) {
1270 /* freed in flight */
1271 ASSERT(zio
== NULL
|| zio
->io_error
== 0);
1272 arc_release(buf
, db
);
1273 bzero(buf
->b_data
, db
->db
.db_size
);
1274 arc_buf_freeze(buf
);
1275 db
->db_freed_in_flight
= FALSE
;
1276 dbuf_set_data(db
, buf
);
1277 db
->db_state
= DB_CACHED
;
1278 DTRACE_SET_STATE(db
, "freed in flight");
1281 ASSERT(zio
== NULL
|| zio
->io_error
== 0);
1282 dbuf_set_data(db
, buf
);
1283 db
->db_state
= DB_CACHED
;
1284 DTRACE_SET_STATE(db
, "successful read");
1286 cv_broadcast(&db
->db_changed
);
1287 dbuf_rele_and_unlock(db
, NULL
, B_FALSE
);
1291 * Shortcut for performing reads on bonus dbufs. Returns
1292 * an error if we fail to verify the dnode associated with
1293 * a decrypted block. Otherwise success.
1296 dbuf_read_bonus(dmu_buf_impl_t
*db
, dnode_t
*dn
, uint32_t flags
)
1298 int bonuslen
, max_bonuslen
, err
;
1300 err
= dbuf_read_verify_dnode_crypt(db
, flags
);
1304 bonuslen
= MIN(dn
->dn_bonuslen
, dn
->dn_phys
->dn_bonuslen
);
1305 max_bonuslen
= DN_SLOTS_TO_BONUSLEN(dn
->dn_num_slots
);
1306 ASSERT(MUTEX_HELD(&db
->db_mtx
));
1307 ASSERT(DB_DNODE_HELD(db
));
1308 ASSERT3U(bonuslen
, <=, db
->db
.db_size
);
1309 db
->db
.db_data
= kmem_alloc(max_bonuslen
, KM_SLEEP
);
1310 arc_space_consume(max_bonuslen
, ARC_SPACE_BONUS
);
1311 if (bonuslen
< max_bonuslen
)
1312 bzero(db
->db
.db_data
, max_bonuslen
);
1314 bcopy(DN_BONUS(dn
->dn_phys
), db
->db
.db_data
, bonuslen
);
1315 db
->db_state
= DB_CACHED
;
1316 DTRACE_SET_STATE(db
, "bonus buffer filled");
1321 dbuf_handle_indirect_hole(dmu_buf_impl_t
*db
, dnode_t
*dn
)
1323 blkptr_t
*bps
= db
->db
.db_data
;
1324 uint32_t indbs
= 1ULL << dn
->dn_indblkshift
;
1325 int n_bps
= indbs
>> SPA_BLKPTRSHIFT
;
1327 for (int i
= 0; i
< n_bps
; i
++) {
1328 blkptr_t
*bp
= &bps
[i
];
1330 ASSERT3U(BP_GET_LSIZE(db
->db_blkptr
), ==, indbs
);
1331 BP_SET_LSIZE(bp
, BP_GET_LEVEL(db
->db_blkptr
) == 1 ?
1332 dn
->dn_datablksz
: BP_GET_LSIZE(db
->db_blkptr
));
1333 BP_SET_TYPE(bp
, BP_GET_TYPE(db
->db_blkptr
));
1334 BP_SET_LEVEL(bp
, BP_GET_LEVEL(db
->db_blkptr
) - 1);
1335 BP_SET_BIRTH(bp
, db
->db_blkptr
->blk_birth
, 0);
1340 * Handle reads on dbufs that are holes, if necessary. This function
1341 * requires that the dbuf's mutex is held. Returns success (0) if action
1342 * was taken, ENOENT if no action was taken.
1345 dbuf_read_hole(dmu_buf_impl_t
*db
, dnode_t
*dn
, uint32_t flags
)
1347 ASSERT(MUTEX_HELD(&db
->db_mtx
));
1349 int is_hole
= db
->db_blkptr
== NULL
|| BP_IS_HOLE(db
->db_blkptr
);
1351 * For level 0 blocks only, if the above check fails:
1352 * Recheck BP_IS_HOLE() after dnode_block_freed() in case dnode_sync()
1353 * processes the delete record and clears the bp while we are waiting
1354 * for the dn_mtx (resulting in a "no" from block_freed).
1356 if (!is_hole
&& db
->db_level
== 0) {
1357 is_hole
= dnode_block_freed(dn
, db
->db_blkid
) ||
1358 BP_IS_HOLE(db
->db_blkptr
);
1362 dbuf_set_data(db
, dbuf_alloc_arcbuf(db
));
1363 bzero(db
->db
.db_data
, db
->db
.db_size
);
1365 if (db
->db_blkptr
!= NULL
&& db
->db_level
> 0 &&
1366 BP_IS_HOLE(db
->db_blkptr
) &&
1367 db
->db_blkptr
->blk_birth
!= 0) {
1368 dbuf_handle_indirect_hole(db
, dn
);
1370 db
->db_state
= DB_CACHED
;
1371 DTRACE_SET_STATE(db
, "hole read satisfied");
1378 * This function ensures that, when doing a decrypting read of a block,
1379 * we make sure we have decrypted the dnode associated with it. We must do
1380 * this so that we ensure we are fully authenticating the checksum-of-MACs
1381 * tree from the root of the objset down to this block. Indirect blocks are
1382 * always verified against their secure checksum-of-MACs assuming that the
1383 * dnode containing them is correct. Now that we are doing a decrypting read,
1384 * we can be sure that the key is loaded and verify that assumption. This is
1385 * especially important considering that we always read encrypted dnode
1386 * blocks as raw data (without verifying their MACs) to start, and
1387 * decrypt / authenticate them when we need to read an encrypted bonus buffer.
1390 dbuf_read_verify_dnode_crypt(dmu_buf_impl_t
*db
, uint32_t flags
)
1393 objset_t
*os
= db
->db_objset
;
1394 arc_buf_t
*dnode_abuf
;
1396 zbookmark_phys_t zb
;
1398 ASSERT(MUTEX_HELD(&db
->db_mtx
));
1400 if (!os
->os_encrypted
|| os
->os_raw_receive
||
1401 (flags
& DB_RF_NO_DECRYPT
) != 0)
1406 dnode_abuf
= (dn
->dn_dbuf
!= NULL
) ? dn
->dn_dbuf
->db_buf
: NULL
;
1408 if (dnode_abuf
== NULL
|| !arc_is_encrypted(dnode_abuf
)) {
1413 SET_BOOKMARK(&zb
, dmu_objset_id(os
),
1414 DMU_META_DNODE_OBJECT
, 0, dn
->dn_dbuf
->db_blkid
);
1415 err
= arc_untransform(dnode_abuf
, os
->os_spa
, &zb
, B_TRUE
);
1418 * An error code of EACCES tells us that the key is still not
1419 * available. This is ok if we are only reading authenticated
1420 * (and therefore non-encrypted) blocks.
1422 if (err
== EACCES
&& ((db
->db_blkid
!= DMU_BONUS_BLKID
&&
1423 !DMU_OT_IS_ENCRYPTED(dn
->dn_type
)) ||
1424 (db
->db_blkid
== DMU_BONUS_BLKID
&&
1425 !DMU_OT_IS_ENCRYPTED(dn
->dn_bonustype
))))
1434 * Drops db_mtx and the parent lock specified by dblt and tag before
1438 dbuf_read_impl(dmu_buf_impl_t
*db
, zio_t
*zio
, uint32_t flags
,
1439 db_lock_type_t dblt
, void *tag
)
1442 zbookmark_phys_t zb
;
1443 uint32_t aflags
= ARC_FLAG_NOWAIT
;
1445 boolean_t bonus_read
;
1447 err
= zio_flags
= 0;
1448 bonus_read
= B_FALSE
;
1451 ASSERT(!zfs_refcount_is_zero(&db
->db_holds
));
1452 ASSERT(MUTEX_HELD(&db
->db_mtx
));
1453 ASSERT(db
->db_state
== DB_UNCACHED
);
1454 ASSERT(db
->db_buf
== NULL
);
1455 ASSERT(db
->db_parent
== NULL
||
1456 RW_LOCK_HELD(&db
->db_parent
->db_rwlock
));
1458 if (db
->db_blkid
== DMU_BONUS_BLKID
) {
1459 err
= dbuf_read_bonus(db
, dn
, flags
);
1463 err
= dbuf_read_hole(db
, dn
, flags
);
1468 * Any attempt to read a redacted block should result in an error. This
1469 * will never happen under normal conditions, but can be useful for
1470 * debugging purposes.
1472 if (BP_IS_REDACTED(db
->db_blkptr
)) {
1473 ASSERT(dsl_dataset_feature_is_active(
1474 db
->db_objset
->os_dsl_dataset
,
1475 SPA_FEATURE_REDACTED_DATASETS
));
1476 err
= SET_ERROR(EIO
);
1480 SET_BOOKMARK(&zb
, dmu_objset_id(db
->db_objset
),
1481 db
->db
.db_object
, db
->db_level
, db
->db_blkid
);
1484 * All bps of an encrypted os should have the encryption bit set.
1485 * If this is not true it indicates tampering and we report an error.
1487 if (db
->db_objset
->os_encrypted
&& !BP_USES_CRYPT(db
->db_blkptr
)) {
1488 spa_log_error(db
->db_objset
->os_spa
, &zb
);
1489 zfs_panic_recover("unencrypted block in encrypted "
1490 "object set %llu", dmu_objset_id(db
->db_objset
));
1491 err
= SET_ERROR(EIO
);
1495 err
= dbuf_read_verify_dnode_crypt(db
, flags
);
1501 db
->db_state
= DB_READ
;
1502 DTRACE_SET_STATE(db
, "read issued");
1503 mutex_exit(&db
->db_mtx
);
1505 if (DBUF_IS_L2CACHEABLE(db
))
1506 aflags
|= ARC_FLAG_L2CACHE
;
1508 dbuf_add_ref(db
, NULL
);
1510 zio_flags
= (flags
& DB_RF_CANFAIL
) ?
1511 ZIO_FLAG_CANFAIL
: ZIO_FLAG_MUSTSUCCEED
;
1513 if ((flags
& DB_RF_NO_DECRYPT
) && BP_IS_PROTECTED(db
->db_blkptr
))
1514 zio_flags
|= ZIO_FLAG_RAW
;
1516 * The zio layer will copy the provided blkptr later, but we need to
1517 * do this now so that we can release the parent's rwlock. We have to
1518 * do that now so that if dbuf_read_done is called synchronously (on
1519 * an l1 cache hit) we don't acquire the db_mtx while holding the
1520 * parent's rwlock, which would be a lock ordering violation.
1522 blkptr_t bp
= *db
->db_blkptr
;
1523 dmu_buf_unlock_parent(db
, dblt
, tag
);
1524 (void) arc_read(zio
, db
->db_objset
->os_spa
, &bp
,
1525 dbuf_read_done
, db
, ZIO_PRIORITY_SYNC_READ
, zio_flags
,
1530 mutex_exit(&db
->db_mtx
);
1531 dmu_buf_unlock_parent(db
, dblt
, tag
);
1536 * This is our just-in-time copy function. It makes a copy of buffers that
1537 * have been modified in a previous transaction group before we access them in
1538 * the current active group.
1540 * This function is used in three places: when we are dirtying a buffer for the
1541 * first time in a txg, when we are freeing a range in a dnode that includes
1542 * this buffer, and when we are accessing a buffer which was received compressed
1543 * and later referenced in a WRITE_BYREF record.
1545 * Note that when we are called from dbuf_free_range() we do not put a hold on
1546 * the buffer, we just traverse the active dbuf list for the dnode.
1549 dbuf_fix_old_data(dmu_buf_impl_t
*db
, uint64_t txg
)
1551 dbuf_dirty_record_t
*dr
= list_head(&db
->db_dirty_records
);
1553 ASSERT(MUTEX_HELD(&db
->db_mtx
));
1554 ASSERT(db
->db
.db_data
!= NULL
);
1555 ASSERT(db
->db_level
== 0);
1556 ASSERT(db
->db
.db_object
!= DMU_META_DNODE_OBJECT
);
1559 (dr
->dt
.dl
.dr_data
!=
1560 ((db
->db_blkid
== DMU_BONUS_BLKID
) ? db
->db
.db_data
: db
->db_buf
)))
1564 * If the last dirty record for this dbuf has not yet synced
1565 * and its referencing the dbuf data, either:
1566 * reset the reference to point to a new copy,
1567 * or (if there a no active holders)
1568 * just null out the current db_data pointer.
1570 ASSERT3U(dr
->dr_txg
, >=, txg
- 2);
1571 if (db
->db_blkid
== DMU_BONUS_BLKID
) {
1572 dnode_t
*dn
= DB_DNODE(db
);
1573 int bonuslen
= DN_SLOTS_TO_BONUSLEN(dn
->dn_num_slots
);
1574 dr
->dt
.dl
.dr_data
= kmem_alloc(bonuslen
, KM_SLEEP
);
1575 arc_space_consume(bonuslen
, ARC_SPACE_BONUS
);
1576 bcopy(db
->db
.db_data
, dr
->dt
.dl
.dr_data
, bonuslen
);
1577 } else if (zfs_refcount_count(&db
->db_holds
) > db
->db_dirtycnt
) {
1578 arc_buf_t
*buf
= dbuf_alloc_arcbuf_from_arcbuf(db
, db
->db_buf
);
1579 dr
->dt
.dl
.dr_data
= buf
;
1580 bcopy(db
->db
.db_data
, buf
->b_data
, arc_buf_size(buf
));
1583 dbuf_clear_data(db
);
1588 dbuf_read(dmu_buf_impl_t
*db
, zio_t
*zio
, uint32_t flags
)
1595 * We don't have to hold the mutex to check db_state because it
1596 * can't be freed while we have a hold on the buffer.
1598 ASSERT(!zfs_refcount_is_zero(&db
->db_holds
));
1600 if (db
->db_state
== DB_NOFILL
)
1601 return (SET_ERROR(EIO
));
1606 prefetch
= db
->db_level
== 0 && db
->db_blkid
!= DMU_BONUS_BLKID
&&
1607 (flags
& DB_RF_NOPREFETCH
) == 0 && dn
!= NULL
&&
1608 DBUF_IS_CACHEABLE(db
);
1610 mutex_enter(&db
->db_mtx
);
1611 if (db
->db_state
== DB_CACHED
) {
1612 spa_t
*spa
= dn
->dn_objset
->os_spa
;
1615 * Ensure that this block's dnode has been decrypted if
1616 * the caller has requested decrypted data.
1618 err
= dbuf_read_verify_dnode_crypt(db
, flags
);
1621 * If the arc buf is compressed or encrypted and the caller
1622 * requested uncompressed data, we need to untransform it
1623 * before returning. We also call arc_untransform() on any
1624 * unauthenticated blocks, which will verify their MAC if
1625 * the key is now available.
1627 if (err
== 0 && db
->db_buf
!= NULL
&&
1628 (flags
& DB_RF_NO_DECRYPT
) == 0 &&
1629 (arc_is_encrypted(db
->db_buf
) ||
1630 arc_is_unauthenticated(db
->db_buf
) ||
1631 arc_get_compression(db
->db_buf
) != ZIO_COMPRESS_OFF
)) {
1632 zbookmark_phys_t zb
;
1634 SET_BOOKMARK(&zb
, dmu_objset_id(db
->db_objset
),
1635 db
->db
.db_object
, db
->db_level
, db
->db_blkid
);
1636 dbuf_fix_old_data(db
, spa_syncing_txg(spa
));
1637 err
= arc_untransform(db
->db_buf
, spa
, &zb
, B_FALSE
);
1638 dbuf_set_data(db
, db
->db_buf
);
1640 mutex_exit(&db
->db_mtx
);
1641 if (err
== 0 && prefetch
) {
1642 dmu_zfetch(&dn
->dn_zfetch
, db
->db_blkid
, 1, B_TRUE
,
1643 flags
& DB_RF_HAVESTRUCT
);
1646 DBUF_STAT_BUMP(hash_hits
);
1647 } else if (db
->db_state
== DB_UNCACHED
) {
1648 spa_t
*spa
= dn
->dn_objset
->os_spa
;
1649 boolean_t need_wait
= B_FALSE
;
1651 db_lock_type_t dblt
= dmu_buf_lock_parent(db
, RW_READER
, FTAG
);
1654 db
->db_blkptr
!= NULL
&& !BP_IS_HOLE(db
->db_blkptr
)) {
1655 zio
= zio_root(spa
, NULL
, NULL
, ZIO_FLAG_CANFAIL
);
1658 err
= dbuf_read_impl(db
, zio
, flags
, dblt
, FTAG
);
1660 * dbuf_read_impl has dropped db_mtx and our parent's rwlock
1663 if (!err
&& prefetch
) {
1664 dmu_zfetch(&dn
->dn_zfetch
, db
->db_blkid
, 1, B_TRUE
,
1665 flags
& DB_RF_HAVESTRUCT
);
1669 DBUF_STAT_BUMP(hash_misses
);
1672 * If we created a zio_root we must execute it to avoid
1673 * leaking it, even if it isn't attached to any work due
1674 * to an error in dbuf_read_impl().
1678 err
= zio_wait(zio
);
1680 VERIFY0(zio_wait(zio
));
1684 * Another reader came in while the dbuf was in flight
1685 * between UNCACHED and CACHED. Either a writer will finish
1686 * writing the buffer (sending the dbuf to CACHED) or the
1687 * first reader's request will reach the read_done callback
1688 * and send the dbuf to CACHED. Otherwise, a failure
1689 * occurred and the dbuf went to UNCACHED.
1691 mutex_exit(&db
->db_mtx
);
1693 dmu_zfetch(&dn
->dn_zfetch
, db
->db_blkid
, 1, B_TRUE
,
1694 flags
& DB_RF_HAVESTRUCT
);
1697 DBUF_STAT_BUMP(hash_misses
);
1699 /* Skip the wait per the caller's request. */
1700 if ((flags
& DB_RF_NEVERWAIT
) == 0) {
1701 mutex_enter(&db
->db_mtx
);
1702 while (db
->db_state
== DB_READ
||
1703 db
->db_state
== DB_FILL
) {
1704 ASSERT(db
->db_state
== DB_READ
||
1705 (flags
& DB_RF_HAVESTRUCT
) == 0);
1706 DTRACE_PROBE2(blocked__read
, dmu_buf_impl_t
*,
1708 cv_wait(&db
->db_changed
, &db
->db_mtx
);
1710 if (db
->db_state
== DB_UNCACHED
)
1711 err
= SET_ERROR(EIO
);
1712 mutex_exit(&db
->db_mtx
);
1720 dbuf_noread(dmu_buf_impl_t
*db
)
1722 ASSERT(!zfs_refcount_is_zero(&db
->db_holds
));
1723 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
1724 mutex_enter(&db
->db_mtx
);
1725 while (db
->db_state
== DB_READ
|| db
->db_state
== DB_FILL
)
1726 cv_wait(&db
->db_changed
, &db
->db_mtx
);
1727 if (db
->db_state
== DB_UNCACHED
) {
1728 ASSERT(db
->db_buf
== NULL
);
1729 ASSERT(db
->db
.db_data
== NULL
);
1730 dbuf_set_data(db
, dbuf_alloc_arcbuf(db
));
1731 db
->db_state
= DB_FILL
;
1732 DTRACE_SET_STATE(db
, "assigning filled buffer");
1733 } else if (db
->db_state
== DB_NOFILL
) {
1734 dbuf_clear_data(db
);
1736 ASSERT3U(db
->db_state
, ==, DB_CACHED
);
1738 mutex_exit(&db
->db_mtx
);
1742 dbuf_unoverride(dbuf_dirty_record_t
*dr
)
1744 dmu_buf_impl_t
*db
= dr
->dr_dbuf
;
1745 blkptr_t
*bp
= &dr
->dt
.dl
.dr_overridden_by
;
1746 uint64_t txg
= dr
->dr_txg
;
1748 ASSERT(MUTEX_HELD(&db
->db_mtx
));
1750 * This assert is valid because dmu_sync() expects to be called by
1751 * a zilog's get_data while holding a range lock. This call only
1752 * comes from dbuf_dirty() callers who must also hold a range lock.
1754 ASSERT(dr
->dt
.dl
.dr_override_state
!= DR_IN_DMU_SYNC
);
1755 ASSERT(db
->db_level
== 0);
1757 if (db
->db_blkid
== DMU_BONUS_BLKID
||
1758 dr
->dt
.dl
.dr_override_state
== DR_NOT_OVERRIDDEN
)
1761 ASSERT(db
->db_data_pending
!= dr
);
1763 /* free this block */
1764 if (!BP_IS_HOLE(bp
) && !dr
->dt
.dl
.dr_nopwrite
)
1765 zio_free(db
->db_objset
->os_spa
, txg
, bp
);
1767 dr
->dt
.dl
.dr_override_state
= DR_NOT_OVERRIDDEN
;
1768 dr
->dt
.dl
.dr_nopwrite
= B_FALSE
;
1769 dr
->dt
.dl
.dr_has_raw_params
= B_FALSE
;
1772 * Release the already-written buffer, so we leave it in
1773 * a consistent dirty state. Note that all callers are
1774 * modifying the buffer, so they will immediately do
1775 * another (redundant) arc_release(). Therefore, leave
1776 * the buf thawed to save the effort of freezing &
1777 * immediately re-thawing it.
1779 arc_release(dr
->dt
.dl
.dr_data
, db
);
1783 * Evict (if its unreferenced) or clear (if its referenced) any level-0
1784 * data blocks in the free range, so that any future readers will find
1788 dbuf_free_range(dnode_t
*dn
, uint64_t start_blkid
, uint64_t end_blkid
,
1791 dmu_buf_impl_t
*db_search
;
1792 dmu_buf_impl_t
*db
, *db_next
;
1793 uint64_t txg
= tx
->tx_txg
;
1795 dbuf_dirty_record_t
*dr
;
1797 if (end_blkid
> dn
->dn_maxblkid
&&
1798 !(start_blkid
== DMU_SPILL_BLKID
|| end_blkid
== DMU_SPILL_BLKID
))
1799 end_blkid
= dn
->dn_maxblkid
;
1800 dprintf_dnode(dn
, "start=%llu end=%llu\n", start_blkid
, end_blkid
);
1802 db_search
= kmem_alloc(sizeof (dmu_buf_impl_t
), KM_SLEEP
);
1803 db_search
->db_level
= 0;
1804 db_search
->db_blkid
= start_blkid
;
1805 db_search
->db_state
= DB_SEARCH
;
1807 mutex_enter(&dn
->dn_dbufs_mtx
);
1808 db
= avl_find(&dn
->dn_dbufs
, db_search
, &where
);
1809 ASSERT3P(db
, ==, NULL
);
1811 db
= avl_nearest(&dn
->dn_dbufs
, where
, AVL_AFTER
);
1813 for (; db
!= NULL
; db
= db_next
) {
1814 db_next
= AVL_NEXT(&dn
->dn_dbufs
, db
);
1815 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
1817 if (db
->db_level
!= 0 || db
->db_blkid
> end_blkid
) {
1820 ASSERT3U(db
->db_blkid
, >=, start_blkid
);
1822 /* found a level 0 buffer in the range */
1823 mutex_enter(&db
->db_mtx
);
1824 if (dbuf_undirty(db
, tx
)) {
1825 /* mutex has been dropped and dbuf destroyed */
1829 if (db
->db_state
== DB_UNCACHED
||
1830 db
->db_state
== DB_NOFILL
||
1831 db
->db_state
== DB_EVICTING
) {
1832 ASSERT(db
->db
.db_data
== NULL
);
1833 mutex_exit(&db
->db_mtx
);
1836 if (db
->db_state
== DB_READ
|| db
->db_state
== DB_FILL
) {
1837 /* will be handled in dbuf_read_done or dbuf_rele */
1838 db
->db_freed_in_flight
= TRUE
;
1839 mutex_exit(&db
->db_mtx
);
1842 if (zfs_refcount_count(&db
->db_holds
) == 0) {
1847 /* The dbuf is referenced */
1849 dr
= list_head(&db
->db_dirty_records
);
1851 if (dr
->dr_txg
== txg
) {
1853 * This buffer is "in-use", re-adjust the file
1854 * size to reflect that this buffer may
1855 * contain new data when we sync.
1857 if (db
->db_blkid
!= DMU_SPILL_BLKID
&&
1858 db
->db_blkid
> dn
->dn_maxblkid
)
1859 dn
->dn_maxblkid
= db
->db_blkid
;
1860 dbuf_unoverride(dr
);
1863 * This dbuf is not dirty in the open context.
1864 * Either uncache it (if its not referenced in
1865 * the open context) or reset its contents to
1868 dbuf_fix_old_data(db
, txg
);
1871 /* clear the contents if its cached */
1872 if (db
->db_state
== DB_CACHED
) {
1873 ASSERT(db
->db
.db_data
!= NULL
);
1874 arc_release(db
->db_buf
, db
);
1875 rw_enter(&db
->db_rwlock
, RW_WRITER
);
1876 bzero(db
->db
.db_data
, db
->db
.db_size
);
1877 rw_exit(&db
->db_rwlock
);
1878 arc_buf_freeze(db
->db_buf
);
1881 mutex_exit(&db
->db_mtx
);
1884 kmem_free(db_search
, sizeof (dmu_buf_impl_t
));
1885 mutex_exit(&dn
->dn_dbufs_mtx
);
1889 dbuf_new_size(dmu_buf_impl_t
*db
, int size
, dmu_tx_t
*tx
)
1891 arc_buf_t
*buf
, *old_buf
;
1892 dbuf_dirty_record_t
*dr
;
1893 int osize
= db
->db
.db_size
;
1894 arc_buf_contents_t type
= DBUF_GET_BUFC_TYPE(db
);
1897 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
1903 * XXX we should be doing a dbuf_read, checking the return
1904 * value and returning that up to our callers
1906 dmu_buf_will_dirty(&db
->db
, tx
);
1908 /* create the data buffer for the new block */
1909 buf
= arc_alloc_buf(dn
->dn_objset
->os_spa
, db
, type
, size
);
1911 /* copy old block data to the new block */
1912 old_buf
= db
->db_buf
;
1913 bcopy(old_buf
->b_data
, buf
->b_data
, MIN(osize
, size
));
1914 /* zero the remainder */
1916 bzero((uint8_t *)buf
->b_data
+ osize
, size
- osize
);
1918 mutex_enter(&db
->db_mtx
);
1919 dbuf_set_data(db
, buf
);
1920 arc_buf_destroy(old_buf
, db
);
1921 db
->db
.db_size
= size
;
1923 dr
= list_head(&db
->db_dirty_records
);
1924 /* dirty record added by dmu_buf_will_dirty() */
1926 if (db
->db_level
== 0)
1927 dr
->dt
.dl
.dr_data
= buf
;
1928 ASSERT3U(dr
->dr_txg
, ==, tx
->tx_txg
);
1929 ASSERT3U(dr
->dr_accounted
, ==, osize
);
1930 dr
->dr_accounted
= size
;
1931 mutex_exit(&db
->db_mtx
);
1933 dmu_objset_willuse_space(dn
->dn_objset
, size
- osize
, tx
);
1938 dbuf_release_bp(dmu_buf_impl_t
*db
)
1940 objset_t
*os __maybe_unused
= db
->db_objset
;
1942 ASSERT(dsl_pool_sync_context(dmu_objset_pool(os
)));
1943 ASSERT(arc_released(os
->os_phys_buf
) ||
1944 list_link_active(&os
->os_dsl_dataset
->ds_synced_link
));
1945 ASSERT(db
->db_parent
== NULL
|| arc_released(db
->db_parent
->db_buf
));
1947 (void) arc_release(db
->db_buf
, db
);
1951 * We already have a dirty record for this TXG, and we are being
1955 dbuf_redirty(dbuf_dirty_record_t
*dr
)
1957 dmu_buf_impl_t
*db
= dr
->dr_dbuf
;
1959 ASSERT(MUTEX_HELD(&db
->db_mtx
));
1961 if (db
->db_level
== 0 && db
->db_blkid
!= DMU_BONUS_BLKID
) {
1963 * If this buffer has already been written out,
1964 * we now need to reset its state.
1966 dbuf_unoverride(dr
);
1967 if (db
->db
.db_object
!= DMU_META_DNODE_OBJECT
&&
1968 db
->db_state
!= DB_NOFILL
) {
1969 /* Already released on initial dirty, so just thaw. */
1970 ASSERT(arc_released(db
->db_buf
));
1971 arc_buf_thaw(db
->db_buf
);
1976 dbuf_dirty_record_t
*
1977 dbuf_dirty_lightweight(dnode_t
*dn
, uint64_t blkid
, dmu_tx_t
*tx
)
1979 rw_enter(&dn
->dn_struct_rwlock
, RW_READER
);
1980 IMPLY(dn
->dn_objset
->os_raw_receive
, dn
->dn_maxblkid
>= blkid
);
1981 dnode_new_blkid(dn
, blkid
, tx
, B_TRUE
, B_FALSE
);
1982 ASSERT(dn
->dn_maxblkid
>= blkid
);
1984 dbuf_dirty_record_t
*dr
= kmem_zalloc(sizeof (*dr
), KM_SLEEP
);
1985 list_link_init(&dr
->dr_dirty_node
);
1986 list_link_init(&dr
->dr_dbuf_node
);
1988 dr
->dr_txg
= tx
->tx_txg
;
1989 dr
->dt
.dll
.dr_blkid
= blkid
;
1990 dr
->dr_accounted
= dn
->dn_datablksz
;
1993 * There should not be any dbuf for the block that we're dirtying.
1994 * Otherwise the buffer contents could be inconsistent between the
1995 * dbuf and the lightweight dirty record.
1997 ASSERT3P(NULL
, ==, dbuf_find(dn
->dn_objset
, dn
->dn_object
, 0, blkid
));
1999 mutex_enter(&dn
->dn_mtx
);
2000 int txgoff
= tx
->tx_txg
& TXG_MASK
;
2001 if (dn
->dn_free_ranges
[txgoff
] != NULL
) {
2002 range_tree_clear(dn
->dn_free_ranges
[txgoff
], blkid
, 1);
2005 if (dn
->dn_nlevels
== 1) {
2006 ASSERT3U(blkid
, <, dn
->dn_nblkptr
);
2007 list_insert_tail(&dn
->dn_dirty_records
[txgoff
], dr
);
2008 mutex_exit(&dn
->dn_mtx
);
2009 rw_exit(&dn
->dn_struct_rwlock
);
2010 dnode_setdirty(dn
, tx
);
2012 mutex_exit(&dn
->dn_mtx
);
2014 int epbs
= dn
->dn_indblkshift
- SPA_BLKPTRSHIFT
;
2015 dmu_buf_impl_t
*parent_db
= dbuf_hold_level(dn
,
2016 1, blkid
>> epbs
, FTAG
);
2017 rw_exit(&dn
->dn_struct_rwlock
);
2018 if (parent_db
== NULL
) {
2019 kmem_free(dr
, sizeof (*dr
));
2022 int err
= dbuf_read(parent_db
, NULL
,
2023 (DB_RF_NOPREFETCH
| DB_RF_CANFAIL
));
2025 dbuf_rele(parent_db
, FTAG
);
2026 kmem_free(dr
, sizeof (*dr
));
2030 dbuf_dirty_record_t
*parent_dr
= dbuf_dirty(parent_db
, tx
);
2031 dbuf_rele(parent_db
, FTAG
);
2032 mutex_enter(&parent_dr
->dt
.di
.dr_mtx
);
2033 ASSERT3U(parent_dr
->dr_txg
, ==, tx
->tx_txg
);
2034 list_insert_tail(&parent_dr
->dt
.di
.dr_children
, dr
);
2035 mutex_exit(&parent_dr
->dt
.di
.dr_mtx
);
2036 dr
->dr_parent
= parent_dr
;
2039 dmu_objset_willuse_space(dn
->dn_objset
, dr
->dr_accounted
, tx
);
2044 dbuf_dirty_record_t
*
2045 dbuf_dirty(dmu_buf_impl_t
*db
, dmu_tx_t
*tx
)
2049 dbuf_dirty_record_t
*dr
, *dr_next
, *dr_head
;
2050 int txgoff
= tx
->tx_txg
& TXG_MASK
;
2051 boolean_t drop_struct_rwlock
= B_FALSE
;
2053 ASSERT(tx
->tx_txg
!= 0);
2054 ASSERT(!zfs_refcount_is_zero(&db
->db_holds
));
2055 DMU_TX_DIRTY_BUF(tx
, db
);
2060 * Shouldn't dirty a regular buffer in syncing context. Private
2061 * objects may be dirtied in syncing context, but only if they
2062 * were already pre-dirtied in open context.
2065 if (dn
->dn_objset
->os_dsl_dataset
!= NULL
) {
2066 rrw_enter(&dn
->dn_objset
->os_dsl_dataset
->ds_bp_rwlock
,
2069 ASSERT(!dmu_tx_is_syncing(tx
) ||
2070 BP_IS_HOLE(dn
->dn_objset
->os_rootbp
) ||
2071 DMU_OBJECT_IS_SPECIAL(dn
->dn_object
) ||
2072 dn
->dn_objset
->os_dsl_dataset
== NULL
);
2073 if (dn
->dn_objset
->os_dsl_dataset
!= NULL
)
2074 rrw_exit(&dn
->dn_objset
->os_dsl_dataset
->ds_bp_rwlock
, FTAG
);
2077 * We make this assert for private objects as well, but after we
2078 * check if we're already dirty. They are allowed to re-dirty
2079 * in syncing context.
2081 ASSERT(dn
->dn_object
== DMU_META_DNODE_OBJECT
||
2082 dn
->dn_dirtyctx
== DN_UNDIRTIED
|| dn
->dn_dirtyctx
==
2083 (dmu_tx_is_syncing(tx
) ? DN_DIRTY_SYNC
: DN_DIRTY_OPEN
));
2085 mutex_enter(&db
->db_mtx
);
2087 * XXX make this true for indirects too? The problem is that
2088 * transactions created with dmu_tx_create_assigned() from
2089 * syncing context don't bother holding ahead.
2091 ASSERT(db
->db_level
!= 0 ||
2092 db
->db_state
== DB_CACHED
|| db
->db_state
== DB_FILL
||
2093 db
->db_state
== DB_NOFILL
);
2095 mutex_enter(&dn
->dn_mtx
);
2096 dnode_set_dirtyctx(dn
, tx
, db
);
2097 if (tx
->tx_txg
> dn
->dn_dirty_txg
)
2098 dn
->dn_dirty_txg
= tx
->tx_txg
;
2099 mutex_exit(&dn
->dn_mtx
);
2101 if (db
->db_blkid
== DMU_SPILL_BLKID
)
2102 dn
->dn_have_spill
= B_TRUE
;
2105 * If this buffer is already dirty, we're done.
2107 dr_head
= list_head(&db
->db_dirty_records
);
2108 ASSERT(dr_head
== NULL
|| dr_head
->dr_txg
<= tx
->tx_txg
||
2109 db
->db
.db_object
== DMU_META_DNODE_OBJECT
);
2110 dr_next
= dbuf_find_dirty_lte(db
, tx
->tx_txg
);
2111 if (dr_next
&& dr_next
->dr_txg
== tx
->tx_txg
) {
2114 dbuf_redirty(dr_next
);
2115 mutex_exit(&db
->db_mtx
);
2120 * Only valid if not already dirty.
2122 ASSERT(dn
->dn_object
== 0 ||
2123 dn
->dn_dirtyctx
== DN_UNDIRTIED
|| dn
->dn_dirtyctx
==
2124 (dmu_tx_is_syncing(tx
) ? DN_DIRTY_SYNC
: DN_DIRTY_OPEN
));
2126 ASSERT3U(dn
->dn_nlevels
, >, db
->db_level
);
2129 * We should only be dirtying in syncing context if it's the
2130 * mos or we're initializing the os or it's a special object.
2131 * However, we are allowed to dirty in syncing context provided
2132 * we already dirtied it in open context. Hence we must make
2133 * this assertion only if we're not already dirty.
2136 VERIFY3U(tx
->tx_txg
, <=, spa_final_dirty_txg(os
->os_spa
));
2138 if (dn
->dn_objset
->os_dsl_dataset
!= NULL
)
2139 rrw_enter(&os
->os_dsl_dataset
->ds_bp_rwlock
, RW_READER
, FTAG
);
2140 ASSERT(!dmu_tx_is_syncing(tx
) || DMU_OBJECT_IS_SPECIAL(dn
->dn_object
) ||
2141 os
->os_dsl_dataset
== NULL
|| BP_IS_HOLE(os
->os_rootbp
));
2142 if (dn
->dn_objset
->os_dsl_dataset
!= NULL
)
2143 rrw_exit(&os
->os_dsl_dataset
->ds_bp_rwlock
, FTAG
);
2145 ASSERT(db
->db
.db_size
!= 0);
2147 dprintf_dbuf(db
, "size=%llx\n", (u_longlong_t
)db
->db
.db_size
);
2149 if (db
->db_blkid
!= DMU_BONUS_BLKID
) {
2150 dmu_objset_willuse_space(os
, db
->db
.db_size
, tx
);
2154 * If this buffer is dirty in an old transaction group we need
2155 * to make a copy of it so that the changes we make in this
2156 * transaction group won't leak out when we sync the older txg.
2158 dr
= kmem_zalloc(sizeof (dbuf_dirty_record_t
), KM_SLEEP
);
2159 list_link_init(&dr
->dr_dirty_node
);
2160 list_link_init(&dr
->dr_dbuf_node
);
2162 if (db
->db_level
== 0) {
2163 void *data_old
= db
->db_buf
;
2165 if (db
->db_state
!= DB_NOFILL
) {
2166 if (db
->db_blkid
== DMU_BONUS_BLKID
) {
2167 dbuf_fix_old_data(db
, tx
->tx_txg
);
2168 data_old
= db
->db
.db_data
;
2169 } else if (db
->db
.db_object
!= DMU_META_DNODE_OBJECT
) {
2171 * Release the data buffer from the cache so
2172 * that we can modify it without impacting
2173 * possible other users of this cached data
2174 * block. Note that indirect blocks and
2175 * private objects are not released until the
2176 * syncing state (since they are only modified
2179 arc_release(db
->db_buf
, db
);
2180 dbuf_fix_old_data(db
, tx
->tx_txg
);
2181 data_old
= db
->db_buf
;
2183 ASSERT(data_old
!= NULL
);
2185 dr
->dt
.dl
.dr_data
= data_old
;
2187 mutex_init(&dr
->dt
.di
.dr_mtx
, NULL
, MUTEX_NOLOCKDEP
, NULL
);
2188 list_create(&dr
->dt
.di
.dr_children
,
2189 sizeof (dbuf_dirty_record_t
),
2190 offsetof(dbuf_dirty_record_t
, dr_dirty_node
));
2192 if (db
->db_blkid
!= DMU_BONUS_BLKID
)
2193 dr
->dr_accounted
= db
->db
.db_size
;
2195 dr
->dr_txg
= tx
->tx_txg
;
2196 list_insert_before(&db
->db_dirty_records
, dr_next
, dr
);
2199 * We could have been freed_in_flight between the dbuf_noread
2200 * and dbuf_dirty. We win, as though the dbuf_noread() had
2201 * happened after the free.
2203 if (db
->db_level
== 0 && db
->db_blkid
!= DMU_BONUS_BLKID
&&
2204 db
->db_blkid
!= DMU_SPILL_BLKID
) {
2205 mutex_enter(&dn
->dn_mtx
);
2206 if (dn
->dn_free_ranges
[txgoff
] != NULL
) {
2207 range_tree_clear(dn
->dn_free_ranges
[txgoff
],
2210 mutex_exit(&dn
->dn_mtx
);
2211 db
->db_freed_in_flight
= FALSE
;
2215 * This buffer is now part of this txg
2217 dbuf_add_ref(db
, (void *)(uintptr_t)tx
->tx_txg
);
2218 db
->db_dirtycnt
+= 1;
2219 ASSERT3U(db
->db_dirtycnt
, <=, 3);
2221 mutex_exit(&db
->db_mtx
);
2223 if (db
->db_blkid
== DMU_BONUS_BLKID
||
2224 db
->db_blkid
== DMU_SPILL_BLKID
) {
2225 mutex_enter(&dn
->dn_mtx
);
2226 ASSERT(!list_link_active(&dr
->dr_dirty_node
));
2227 list_insert_tail(&dn
->dn_dirty_records
[txgoff
], dr
);
2228 mutex_exit(&dn
->dn_mtx
);
2229 dnode_setdirty(dn
, tx
);
2234 if (!RW_WRITE_HELD(&dn
->dn_struct_rwlock
)) {
2235 rw_enter(&dn
->dn_struct_rwlock
, RW_READER
);
2236 drop_struct_rwlock
= B_TRUE
;
2240 * If we are overwriting a dedup BP, then unless it is snapshotted,
2241 * when we get to syncing context we will need to decrement its
2242 * refcount in the DDT. Prefetch the relevant DDT block so that
2243 * syncing context won't have to wait for the i/o.
2245 if (db
->db_blkptr
!= NULL
) {
2246 db_lock_type_t dblt
= dmu_buf_lock_parent(db
, RW_READER
, FTAG
);
2247 ddt_prefetch(os
->os_spa
, db
->db_blkptr
);
2248 dmu_buf_unlock_parent(db
, dblt
, FTAG
);
2252 * We need to hold the dn_struct_rwlock to make this assertion,
2253 * because it protects dn_phys / dn_next_nlevels from changing.
2255 ASSERT((dn
->dn_phys
->dn_nlevels
== 0 && db
->db_level
== 0) ||
2256 dn
->dn_phys
->dn_nlevels
> db
->db_level
||
2257 dn
->dn_next_nlevels
[txgoff
] > db
->db_level
||
2258 dn
->dn_next_nlevels
[(tx
->tx_txg
-1) & TXG_MASK
] > db
->db_level
||
2259 dn
->dn_next_nlevels
[(tx
->tx_txg
-2) & TXG_MASK
] > db
->db_level
);
2262 if (db
->db_level
== 0) {
2263 ASSERT(!db
->db_objset
->os_raw_receive
||
2264 dn
->dn_maxblkid
>= db
->db_blkid
);
2265 dnode_new_blkid(dn
, db
->db_blkid
, tx
,
2266 drop_struct_rwlock
, B_FALSE
);
2267 ASSERT(dn
->dn_maxblkid
>= db
->db_blkid
);
2270 if (db
->db_level
+1 < dn
->dn_nlevels
) {
2271 dmu_buf_impl_t
*parent
= db
->db_parent
;
2272 dbuf_dirty_record_t
*di
;
2273 int parent_held
= FALSE
;
2275 if (db
->db_parent
== NULL
|| db
->db_parent
== dn
->dn_dbuf
) {
2276 int epbs
= dn
->dn_indblkshift
- SPA_BLKPTRSHIFT
;
2277 parent
= dbuf_hold_level(dn
, db
->db_level
+ 1,
2278 db
->db_blkid
>> epbs
, FTAG
);
2279 ASSERT(parent
!= NULL
);
2282 if (drop_struct_rwlock
)
2283 rw_exit(&dn
->dn_struct_rwlock
);
2284 ASSERT3U(db
->db_level
+ 1, ==, parent
->db_level
);
2285 di
= dbuf_dirty(parent
, tx
);
2287 dbuf_rele(parent
, FTAG
);
2289 mutex_enter(&db
->db_mtx
);
2291 * Since we've dropped the mutex, it's possible that
2292 * dbuf_undirty() might have changed this out from under us.
2294 if (list_head(&db
->db_dirty_records
) == dr
||
2295 dn
->dn_object
== DMU_META_DNODE_OBJECT
) {
2296 mutex_enter(&di
->dt
.di
.dr_mtx
);
2297 ASSERT3U(di
->dr_txg
, ==, tx
->tx_txg
);
2298 ASSERT(!list_link_active(&dr
->dr_dirty_node
));
2299 list_insert_tail(&di
->dt
.di
.dr_children
, dr
);
2300 mutex_exit(&di
->dt
.di
.dr_mtx
);
2303 mutex_exit(&db
->db_mtx
);
2305 ASSERT(db
->db_level
+ 1 == dn
->dn_nlevels
);
2306 ASSERT(db
->db_blkid
< dn
->dn_nblkptr
);
2307 ASSERT(db
->db_parent
== NULL
|| db
->db_parent
== dn
->dn_dbuf
);
2308 mutex_enter(&dn
->dn_mtx
);
2309 ASSERT(!list_link_active(&dr
->dr_dirty_node
));
2310 list_insert_tail(&dn
->dn_dirty_records
[txgoff
], dr
);
2311 mutex_exit(&dn
->dn_mtx
);
2312 if (drop_struct_rwlock
)
2313 rw_exit(&dn
->dn_struct_rwlock
);
2316 dnode_setdirty(dn
, tx
);
2322 dbuf_undirty_bonus(dbuf_dirty_record_t
*dr
)
2324 dmu_buf_impl_t
*db
= dr
->dr_dbuf
;
2326 if (dr
->dt
.dl
.dr_data
!= db
->db
.db_data
) {
2327 struct dnode
*dn
= dr
->dr_dnode
;
2328 int max_bonuslen
= DN_SLOTS_TO_BONUSLEN(dn
->dn_num_slots
);
2330 kmem_free(dr
->dt
.dl
.dr_data
, max_bonuslen
);
2331 arc_space_return(max_bonuslen
, ARC_SPACE_BONUS
);
2333 db
->db_data_pending
= NULL
;
2334 ASSERT(list_next(&db
->db_dirty_records
, dr
) == NULL
);
2335 list_remove(&db
->db_dirty_records
, dr
);
2336 if (dr
->dr_dbuf
->db_level
!= 0) {
2337 mutex_destroy(&dr
->dt
.di
.dr_mtx
);
2338 list_destroy(&dr
->dt
.di
.dr_children
);
2340 kmem_free(dr
, sizeof (dbuf_dirty_record_t
));
2341 ASSERT3U(db
->db_dirtycnt
, >, 0);
2342 db
->db_dirtycnt
-= 1;
2346 * Undirty a buffer in the transaction group referenced by the given
2347 * transaction. Return whether this evicted the dbuf.
2350 dbuf_undirty(dmu_buf_impl_t
*db
, dmu_tx_t
*tx
)
2352 uint64_t txg
= tx
->tx_txg
;
2357 * Due to our use of dn_nlevels below, this can only be called
2358 * in open context, unless we are operating on the MOS.
2359 * From syncing context, dn_nlevels may be different from the
2360 * dn_nlevels used when dbuf was dirtied.
2362 ASSERT(db
->db_objset
==
2363 dmu_objset_pool(db
->db_objset
)->dp_meta_objset
||
2364 txg
!= spa_syncing_txg(dmu_objset_spa(db
->db_objset
)));
2365 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
2366 ASSERT0(db
->db_level
);
2367 ASSERT(MUTEX_HELD(&db
->db_mtx
));
2370 * If this buffer is not dirty, we're done.
2372 dbuf_dirty_record_t
*dr
= dbuf_find_dirty_eq(db
, txg
);
2375 ASSERT(dr
->dr_dbuf
== db
);
2377 dnode_t
*dn
= dr
->dr_dnode
;
2379 dprintf_dbuf(db
, "size=%llx\n", (u_longlong_t
)db
->db
.db_size
);
2381 ASSERT(db
->db
.db_size
!= 0);
2383 dsl_pool_undirty_space(dmu_objset_pool(dn
->dn_objset
),
2384 dr
->dr_accounted
, txg
);
2386 list_remove(&db
->db_dirty_records
, dr
);
2389 * Note that there are three places in dbuf_dirty()
2390 * where this dirty record may be put on a list.
2391 * Make sure to do a list_remove corresponding to
2392 * every one of those list_insert calls.
2394 if (dr
->dr_parent
) {
2395 mutex_enter(&dr
->dr_parent
->dt
.di
.dr_mtx
);
2396 list_remove(&dr
->dr_parent
->dt
.di
.dr_children
, dr
);
2397 mutex_exit(&dr
->dr_parent
->dt
.di
.dr_mtx
);
2398 } else if (db
->db_blkid
== DMU_SPILL_BLKID
||
2399 db
->db_level
+ 1 == dn
->dn_nlevels
) {
2400 ASSERT(db
->db_blkptr
== NULL
|| db
->db_parent
== dn
->dn_dbuf
);
2401 mutex_enter(&dn
->dn_mtx
);
2402 list_remove(&dn
->dn_dirty_records
[txg
& TXG_MASK
], dr
);
2403 mutex_exit(&dn
->dn_mtx
);
2406 if (db
->db_state
!= DB_NOFILL
) {
2407 dbuf_unoverride(dr
);
2409 ASSERT(db
->db_buf
!= NULL
);
2410 ASSERT(dr
->dt
.dl
.dr_data
!= NULL
);
2411 if (dr
->dt
.dl
.dr_data
!= db
->db_buf
)
2412 arc_buf_destroy(dr
->dt
.dl
.dr_data
, db
);
2415 kmem_free(dr
, sizeof (dbuf_dirty_record_t
));
2417 ASSERT(db
->db_dirtycnt
> 0);
2418 db
->db_dirtycnt
-= 1;
2420 if (zfs_refcount_remove(&db
->db_holds
, (void *)(uintptr_t)txg
) == 0) {
2421 ASSERT(db
->db_state
== DB_NOFILL
|| arc_released(db
->db_buf
));
2430 dmu_buf_will_dirty_impl(dmu_buf_t
*db_fake
, int flags
, dmu_tx_t
*tx
)
2432 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)db_fake
;
2434 ASSERT(tx
->tx_txg
!= 0);
2435 ASSERT(!zfs_refcount_is_zero(&db
->db_holds
));
2438 * Quick check for dirtiness. For already dirty blocks, this
2439 * reduces runtime of this function by >90%, and overall performance
2440 * by 50% for some workloads (e.g. file deletion with indirect blocks
2443 mutex_enter(&db
->db_mtx
);
2445 if (db
->db_state
== DB_CACHED
) {
2446 dbuf_dirty_record_t
*dr
= dbuf_find_dirty_eq(db
, tx
->tx_txg
);
2448 * It's possible that it is already dirty but not cached,
2449 * because there are some calls to dbuf_dirty() that don't
2450 * go through dmu_buf_will_dirty().
2453 /* This dbuf is already dirty and cached. */
2455 mutex_exit(&db
->db_mtx
);
2459 mutex_exit(&db
->db_mtx
);
2462 if (RW_WRITE_HELD(&DB_DNODE(db
)->dn_struct_rwlock
))
2463 flags
|= DB_RF_HAVESTRUCT
;
2465 (void) dbuf_read(db
, NULL
, flags
);
2466 (void) dbuf_dirty(db
, tx
);
2470 dmu_buf_will_dirty(dmu_buf_t
*db_fake
, dmu_tx_t
*tx
)
2472 dmu_buf_will_dirty_impl(db_fake
,
2473 DB_RF_MUST_SUCCEED
| DB_RF_NOPREFETCH
, tx
);
2477 dmu_buf_is_dirty(dmu_buf_t
*db_fake
, dmu_tx_t
*tx
)
2479 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)db_fake
;
2480 dbuf_dirty_record_t
*dr
;
2482 mutex_enter(&db
->db_mtx
);
2483 dr
= dbuf_find_dirty_eq(db
, tx
->tx_txg
);
2484 mutex_exit(&db
->db_mtx
);
2485 return (dr
!= NULL
);
2489 dmu_buf_will_not_fill(dmu_buf_t
*db_fake
, dmu_tx_t
*tx
)
2491 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)db_fake
;
2493 db
->db_state
= DB_NOFILL
;
2494 DTRACE_SET_STATE(db
, "allocating NOFILL buffer");
2495 dmu_buf_will_fill(db_fake
, tx
);
2499 dmu_buf_will_fill(dmu_buf_t
*db_fake
, dmu_tx_t
*tx
)
2501 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)db_fake
;
2503 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
2504 ASSERT(tx
->tx_txg
!= 0);
2505 ASSERT(db
->db_level
== 0);
2506 ASSERT(!zfs_refcount_is_zero(&db
->db_holds
));
2508 ASSERT(db
->db
.db_object
!= DMU_META_DNODE_OBJECT
||
2509 dmu_tx_private_ok(tx
));
2512 (void) dbuf_dirty(db
, tx
);
2516 * This function is effectively the same as dmu_buf_will_dirty(), but
2517 * indicates the caller expects raw encrypted data in the db, and provides
2518 * the crypt params (byteorder, salt, iv, mac) which should be stored in the
2519 * blkptr_t when this dbuf is written. This is only used for blocks of
2520 * dnodes, during raw receive.
2523 dmu_buf_set_crypt_params(dmu_buf_t
*db_fake
, boolean_t byteorder
,
2524 const uint8_t *salt
, const uint8_t *iv
, const uint8_t *mac
, dmu_tx_t
*tx
)
2526 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)db_fake
;
2527 dbuf_dirty_record_t
*dr
;
2530 * dr_has_raw_params is only processed for blocks of dnodes
2531 * (see dbuf_sync_dnode_leaf_crypt()).
2533 ASSERT3U(db
->db
.db_object
, ==, DMU_META_DNODE_OBJECT
);
2534 ASSERT3U(db
->db_level
, ==, 0);
2535 ASSERT(db
->db_objset
->os_raw_receive
);
2537 dmu_buf_will_dirty_impl(db_fake
,
2538 DB_RF_MUST_SUCCEED
| DB_RF_NOPREFETCH
| DB_RF_NO_DECRYPT
, tx
);
2540 dr
= dbuf_find_dirty_eq(db
, tx
->tx_txg
);
2542 ASSERT3P(dr
, !=, NULL
);
2544 dr
->dt
.dl
.dr_has_raw_params
= B_TRUE
;
2545 dr
->dt
.dl
.dr_byteorder
= byteorder
;
2546 bcopy(salt
, dr
->dt
.dl
.dr_salt
, ZIO_DATA_SALT_LEN
);
2547 bcopy(iv
, dr
->dt
.dl
.dr_iv
, ZIO_DATA_IV_LEN
);
2548 bcopy(mac
, dr
->dt
.dl
.dr_mac
, ZIO_DATA_MAC_LEN
);
2552 dbuf_override_impl(dmu_buf_impl_t
*db
, const blkptr_t
*bp
, dmu_tx_t
*tx
)
2554 struct dirty_leaf
*dl
;
2555 dbuf_dirty_record_t
*dr
;
2557 dr
= list_head(&db
->db_dirty_records
);
2558 ASSERT3U(dr
->dr_txg
, ==, tx
->tx_txg
);
2560 dl
->dr_overridden_by
= *bp
;
2561 dl
->dr_override_state
= DR_OVERRIDDEN
;
2562 dl
->dr_overridden_by
.blk_birth
= dr
->dr_txg
;
2567 dmu_buf_fill_done(dmu_buf_t
*dbuf
, dmu_tx_t
*tx
)
2569 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)dbuf
;
2570 dbuf_states_t old_state
;
2571 mutex_enter(&db
->db_mtx
);
2574 old_state
= db
->db_state
;
2575 db
->db_state
= DB_CACHED
;
2576 if (old_state
== DB_FILL
) {
2577 if (db
->db_level
== 0 && db
->db_freed_in_flight
) {
2578 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
2579 /* we were freed while filling */
2580 /* XXX dbuf_undirty? */
2581 bzero(db
->db
.db_data
, db
->db
.db_size
);
2582 db
->db_freed_in_flight
= FALSE
;
2583 DTRACE_SET_STATE(db
,
2584 "fill done handling freed in flight");
2586 DTRACE_SET_STATE(db
, "fill done");
2588 cv_broadcast(&db
->db_changed
);
2590 mutex_exit(&db
->db_mtx
);
2594 dmu_buf_write_embedded(dmu_buf_t
*dbuf
, void *data
,
2595 bp_embedded_type_t etype
, enum zio_compress comp
,
2596 int uncompressed_size
, int compressed_size
, int byteorder
,
2599 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)dbuf
;
2600 struct dirty_leaf
*dl
;
2601 dmu_object_type_t type
;
2602 dbuf_dirty_record_t
*dr
;
2604 if (etype
== BP_EMBEDDED_TYPE_DATA
) {
2605 ASSERT(spa_feature_is_active(dmu_objset_spa(db
->db_objset
),
2606 SPA_FEATURE_EMBEDDED_DATA
));
2610 type
= DB_DNODE(db
)->dn_type
;
2613 ASSERT0(db
->db_level
);
2614 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
2616 dmu_buf_will_not_fill(dbuf
, tx
);
2618 dr
= list_head(&db
->db_dirty_records
);
2619 ASSERT3U(dr
->dr_txg
, ==, tx
->tx_txg
);
2621 encode_embedded_bp_compressed(&dl
->dr_overridden_by
,
2622 data
, comp
, uncompressed_size
, compressed_size
);
2623 BPE_SET_ETYPE(&dl
->dr_overridden_by
, etype
);
2624 BP_SET_TYPE(&dl
->dr_overridden_by
, type
);
2625 BP_SET_LEVEL(&dl
->dr_overridden_by
, 0);
2626 BP_SET_BYTEORDER(&dl
->dr_overridden_by
, byteorder
);
2628 dl
->dr_override_state
= DR_OVERRIDDEN
;
2629 dl
->dr_overridden_by
.blk_birth
= dr
->dr_txg
;
2633 dmu_buf_redact(dmu_buf_t
*dbuf
, dmu_tx_t
*tx
)
2635 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)dbuf
;
2636 dmu_object_type_t type
;
2637 ASSERT(dsl_dataset_feature_is_active(db
->db_objset
->os_dsl_dataset
,
2638 SPA_FEATURE_REDACTED_DATASETS
));
2641 type
= DB_DNODE(db
)->dn_type
;
2644 ASSERT0(db
->db_level
);
2645 dmu_buf_will_not_fill(dbuf
, tx
);
2647 blkptr_t bp
= { { { {0} } } };
2648 BP_SET_TYPE(&bp
, type
);
2649 BP_SET_LEVEL(&bp
, 0);
2650 BP_SET_BIRTH(&bp
, tx
->tx_txg
, 0);
2651 BP_SET_REDACTED(&bp
);
2652 BPE_SET_LSIZE(&bp
, dbuf
->db_size
);
2654 dbuf_override_impl(db
, &bp
, tx
);
2658 * Directly assign a provided arc buf to a given dbuf if it's not referenced
2659 * by anybody except our caller. Otherwise copy arcbuf's contents to dbuf.
2662 dbuf_assign_arcbuf(dmu_buf_impl_t
*db
, arc_buf_t
*buf
, dmu_tx_t
*tx
)
2664 ASSERT(!zfs_refcount_is_zero(&db
->db_holds
));
2665 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
2666 ASSERT(db
->db_level
== 0);
2667 ASSERT3U(dbuf_is_metadata(db
), ==, arc_is_metadata(buf
));
2668 ASSERT(buf
!= NULL
);
2669 ASSERT3U(arc_buf_lsize(buf
), ==, db
->db
.db_size
);
2670 ASSERT(tx
->tx_txg
!= 0);
2672 arc_return_buf(buf
, db
);
2673 ASSERT(arc_released(buf
));
2675 mutex_enter(&db
->db_mtx
);
2677 while (db
->db_state
== DB_READ
|| db
->db_state
== DB_FILL
)
2678 cv_wait(&db
->db_changed
, &db
->db_mtx
);
2680 ASSERT(db
->db_state
== DB_CACHED
|| db
->db_state
== DB_UNCACHED
);
2682 if (db
->db_state
== DB_CACHED
&&
2683 zfs_refcount_count(&db
->db_holds
) - 1 > db
->db_dirtycnt
) {
2685 * In practice, we will never have a case where we have an
2686 * encrypted arc buffer while additional holds exist on the
2687 * dbuf. We don't handle this here so we simply assert that
2690 ASSERT(!arc_is_encrypted(buf
));
2691 mutex_exit(&db
->db_mtx
);
2692 (void) dbuf_dirty(db
, tx
);
2693 bcopy(buf
->b_data
, db
->db
.db_data
, db
->db
.db_size
);
2694 arc_buf_destroy(buf
, db
);
2698 if (db
->db_state
== DB_CACHED
) {
2699 dbuf_dirty_record_t
*dr
= list_head(&db
->db_dirty_records
);
2701 ASSERT(db
->db_buf
!= NULL
);
2702 if (dr
!= NULL
&& dr
->dr_txg
== tx
->tx_txg
) {
2703 ASSERT(dr
->dt
.dl
.dr_data
== db
->db_buf
);
2705 if (!arc_released(db
->db_buf
)) {
2706 ASSERT(dr
->dt
.dl
.dr_override_state
==
2708 arc_release(db
->db_buf
, db
);
2710 dr
->dt
.dl
.dr_data
= buf
;
2711 arc_buf_destroy(db
->db_buf
, db
);
2712 } else if (dr
== NULL
|| dr
->dt
.dl
.dr_data
!= db
->db_buf
) {
2713 arc_release(db
->db_buf
, db
);
2714 arc_buf_destroy(db
->db_buf
, db
);
2718 ASSERT(db
->db_buf
== NULL
);
2719 dbuf_set_data(db
, buf
);
2720 db
->db_state
= DB_FILL
;
2721 DTRACE_SET_STATE(db
, "filling assigned arcbuf");
2722 mutex_exit(&db
->db_mtx
);
2723 (void) dbuf_dirty(db
, tx
);
2724 dmu_buf_fill_done(&db
->db
, tx
);
2728 dbuf_destroy(dmu_buf_impl_t
*db
)
2731 dmu_buf_impl_t
*parent
= db
->db_parent
;
2732 dmu_buf_impl_t
*dndb
;
2734 ASSERT(MUTEX_HELD(&db
->db_mtx
));
2735 ASSERT(zfs_refcount_is_zero(&db
->db_holds
));
2737 if (db
->db_buf
!= NULL
) {
2738 arc_buf_destroy(db
->db_buf
, db
);
2742 if (db
->db_blkid
== DMU_BONUS_BLKID
) {
2743 int slots
= DB_DNODE(db
)->dn_num_slots
;
2744 int bonuslen
= DN_SLOTS_TO_BONUSLEN(slots
);
2745 if (db
->db
.db_data
!= NULL
) {
2746 kmem_free(db
->db
.db_data
, bonuslen
);
2747 arc_space_return(bonuslen
, ARC_SPACE_BONUS
);
2748 db
->db_state
= DB_UNCACHED
;
2749 DTRACE_SET_STATE(db
, "buffer cleared");
2753 dbuf_clear_data(db
);
2755 if (multilist_link_active(&db
->db_cache_link
)) {
2756 ASSERT(db
->db_caching_status
== DB_DBUF_CACHE
||
2757 db
->db_caching_status
== DB_DBUF_METADATA_CACHE
);
2759 multilist_remove(dbuf_caches
[db
->db_caching_status
].cache
, db
);
2760 (void) zfs_refcount_remove_many(
2761 &dbuf_caches
[db
->db_caching_status
].size
,
2762 db
->db
.db_size
, db
);
2764 if (db
->db_caching_status
== DB_DBUF_METADATA_CACHE
) {
2765 DBUF_STAT_BUMPDOWN(metadata_cache_count
);
2767 DBUF_STAT_BUMPDOWN(cache_levels
[db
->db_level
]);
2768 DBUF_STAT_BUMPDOWN(cache_count
);
2769 DBUF_STAT_DECR(cache_levels_bytes
[db
->db_level
],
2772 db
->db_caching_status
= DB_NO_CACHE
;
2775 ASSERT(db
->db_state
== DB_UNCACHED
|| db
->db_state
== DB_NOFILL
);
2776 ASSERT(db
->db_data_pending
== NULL
);
2777 ASSERT(list_is_empty(&db
->db_dirty_records
));
2779 db
->db_state
= DB_EVICTING
;
2780 DTRACE_SET_STATE(db
, "buffer eviction started");
2781 db
->db_blkptr
= NULL
;
2784 * Now that db_state is DB_EVICTING, nobody else can find this via
2785 * the hash table. We can now drop db_mtx, which allows us to
2786 * acquire the dn_dbufs_mtx.
2788 mutex_exit(&db
->db_mtx
);
2793 if (db
->db_blkid
!= DMU_BONUS_BLKID
) {
2794 boolean_t needlock
= !MUTEX_HELD(&dn
->dn_dbufs_mtx
);
2796 mutex_enter_nested(&dn
->dn_dbufs_mtx
,
2798 avl_remove(&dn
->dn_dbufs
, db
);
2802 mutex_exit(&dn
->dn_dbufs_mtx
);
2804 * Decrementing the dbuf count means that the hold corresponding
2805 * to the removed dbuf is no longer discounted in dnode_move(),
2806 * so the dnode cannot be moved until after we release the hold.
2807 * The membar_producer() ensures visibility of the decremented
2808 * value in dnode_move(), since DB_DNODE_EXIT doesn't actually
2811 mutex_enter(&dn
->dn_mtx
);
2812 dnode_rele_and_unlock(dn
, db
, B_TRUE
);
2813 db
->db_dnode_handle
= NULL
;
2815 dbuf_hash_remove(db
);
2820 ASSERT(zfs_refcount_is_zero(&db
->db_holds
));
2822 db
->db_parent
= NULL
;
2824 ASSERT(db
->db_buf
== NULL
);
2825 ASSERT(db
->db
.db_data
== NULL
);
2826 ASSERT(db
->db_hash_next
== NULL
);
2827 ASSERT(db
->db_blkptr
== NULL
);
2828 ASSERT(db
->db_data_pending
== NULL
);
2829 ASSERT3U(db
->db_caching_status
, ==, DB_NO_CACHE
);
2830 ASSERT(!multilist_link_active(&db
->db_cache_link
));
2832 kmem_cache_free(dbuf_kmem_cache
, db
);
2833 arc_space_return(sizeof (dmu_buf_impl_t
), ARC_SPACE_DBUF
);
2836 * If this dbuf is referenced from an indirect dbuf,
2837 * decrement the ref count on the indirect dbuf.
2839 if (parent
&& parent
!= dndb
) {
2840 mutex_enter(&parent
->db_mtx
);
2841 dbuf_rele_and_unlock(parent
, db
, B_TRUE
);
2846 * Note: While bpp will always be updated if the function returns success,
2847 * parentp will not be updated if the dnode does not have dn_dbuf filled in;
2848 * this happens when the dnode is the meta-dnode, or {user|group|project}used
2851 __attribute__((always_inline
))
2853 dbuf_findbp(dnode_t
*dn
, int level
, uint64_t blkid
, int fail_sparse
,
2854 dmu_buf_impl_t
**parentp
, blkptr_t
**bpp
)
2859 ASSERT(blkid
!= DMU_BONUS_BLKID
);
2861 if (blkid
== DMU_SPILL_BLKID
) {
2862 mutex_enter(&dn
->dn_mtx
);
2863 if (dn
->dn_have_spill
&&
2864 (dn
->dn_phys
->dn_flags
& DNODE_FLAG_SPILL_BLKPTR
))
2865 *bpp
= DN_SPILL_BLKPTR(dn
->dn_phys
);
2868 dbuf_add_ref(dn
->dn_dbuf
, NULL
);
2869 *parentp
= dn
->dn_dbuf
;
2870 mutex_exit(&dn
->dn_mtx
);
2875 (dn
->dn_phys
->dn_nlevels
== 0) ? 1 : dn
->dn_phys
->dn_nlevels
;
2876 int epbs
= dn
->dn_indblkshift
- SPA_BLKPTRSHIFT
;
2878 ASSERT3U(level
* epbs
, <, 64);
2879 ASSERT(RW_LOCK_HELD(&dn
->dn_struct_rwlock
));
2881 * This assertion shouldn't trip as long as the max indirect block size
2882 * is less than 1M. The reason for this is that up to that point,
2883 * the number of levels required to address an entire object with blocks
2884 * of size SPA_MINBLOCKSIZE satisfies nlevels * epbs + 1 <= 64. In
2885 * other words, if N * epbs + 1 > 64, then if (N-1) * epbs + 1 > 55
2886 * (i.e. we can address the entire object), objects will all use at most
2887 * N-1 levels and the assertion won't overflow. However, once epbs is
2888 * 13, 4 * 13 + 1 = 53, but 5 * 13 + 1 = 66. Then, 4 levels will not be
2889 * enough to address an entire object, so objects will have 5 levels,
2890 * but then this assertion will overflow.
2892 * All this is to say that if we ever increase DN_MAX_INDBLKSHIFT, we
2893 * need to redo this logic to handle overflows.
2895 ASSERT(level
>= nlevels
||
2896 ((nlevels
- level
- 1) * epbs
) +
2897 highbit64(dn
->dn_phys
->dn_nblkptr
) <= 64);
2898 if (level
>= nlevels
||
2899 blkid
>= ((uint64_t)dn
->dn_phys
->dn_nblkptr
<<
2900 ((nlevels
- level
- 1) * epbs
)) ||
2902 blkid
> (dn
->dn_phys
->dn_maxblkid
>> (level
* epbs
)))) {
2903 /* the buffer has no parent yet */
2904 return (SET_ERROR(ENOENT
));
2905 } else if (level
< nlevels
-1) {
2906 /* this block is referenced from an indirect block */
2909 err
= dbuf_hold_impl(dn
, level
+ 1,
2910 blkid
>> epbs
, fail_sparse
, FALSE
, NULL
, parentp
);
2914 err
= dbuf_read(*parentp
, NULL
,
2915 (DB_RF_HAVESTRUCT
| DB_RF_NOPREFETCH
| DB_RF_CANFAIL
));
2917 dbuf_rele(*parentp
, NULL
);
2921 rw_enter(&(*parentp
)->db_rwlock
, RW_READER
);
2922 *bpp
= ((blkptr_t
*)(*parentp
)->db
.db_data
) +
2923 (blkid
& ((1ULL << epbs
) - 1));
2924 if (blkid
> (dn
->dn_phys
->dn_maxblkid
>> (level
* epbs
)))
2925 ASSERT(BP_IS_HOLE(*bpp
));
2926 rw_exit(&(*parentp
)->db_rwlock
);
2929 /* the block is referenced from the dnode */
2930 ASSERT3U(level
, ==, nlevels
-1);
2931 ASSERT(dn
->dn_phys
->dn_nblkptr
== 0 ||
2932 blkid
< dn
->dn_phys
->dn_nblkptr
);
2934 dbuf_add_ref(dn
->dn_dbuf
, NULL
);
2935 *parentp
= dn
->dn_dbuf
;
2937 *bpp
= &dn
->dn_phys
->dn_blkptr
[blkid
];
2942 static dmu_buf_impl_t
*
2943 dbuf_create(dnode_t
*dn
, uint8_t level
, uint64_t blkid
,
2944 dmu_buf_impl_t
*parent
, blkptr_t
*blkptr
)
2946 objset_t
*os
= dn
->dn_objset
;
2947 dmu_buf_impl_t
*db
, *odb
;
2949 ASSERT(RW_LOCK_HELD(&dn
->dn_struct_rwlock
));
2950 ASSERT(dn
->dn_type
!= DMU_OT_NONE
);
2952 db
= kmem_cache_alloc(dbuf_kmem_cache
, KM_SLEEP
);
2954 list_create(&db
->db_dirty_records
, sizeof (dbuf_dirty_record_t
),
2955 offsetof(dbuf_dirty_record_t
, dr_dbuf_node
));
2958 db
->db
.db_object
= dn
->dn_object
;
2959 db
->db_level
= level
;
2960 db
->db_blkid
= blkid
;
2961 db
->db_dirtycnt
= 0;
2962 db
->db_dnode_handle
= dn
->dn_handle
;
2963 db
->db_parent
= parent
;
2964 db
->db_blkptr
= blkptr
;
2967 db
->db_user_immediate_evict
= FALSE
;
2968 db
->db_freed_in_flight
= FALSE
;
2969 db
->db_pending_evict
= FALSE
;
2971 if (blkid
== DMU_BONUS_BLKID
) {
2972 ASSERT3P(parent
, ==, dn
->dn_dbuf
);
2973 db
->db
.db_size
= DN_SLOTS_TO_BONUSLEN(dn
->dn_num_slots
) -
2974 (dn
->dn_nblkptr
-1) * sizeof (blkptr_t
);
2975 ASSERT3U(db
->db
.db_size
, >=, dn
->dn_bonuslen
);
2976 db
->db
.db_offset
= DMU_BONUS_BLKID
;
2977 db
->db_state
= DB_UNCACHED
;
2978 DTRACE_SET_STATE(db
, "bonus buffer created");
2979 db
->db_caching_status
= DB_NO_CACHE
;
2980 /* the bonus dbuf is not placed in the hash table */
2981 arc_space_consume(sizeof (dmu_buf_impl_t
), ARC_SPACE_DBUF
);
2983 } else if (blkid
== DMU_SPILL_BLKID
) {
2984 db
->db
.db_size
= (blkptr
!= NULL
) ?
2985 BP_GET_LSIZE(blkptr
) : SPA_MINBLOCKSIZE
;
2986 db
->db
.db_offset
= 0;
2989 db
->db_level
? 1 << dn
->dn_indblkshift
: dn
->dn_datablksz
;
2990 db
->db
.db_size
= blocksize
;
2991 db
->db
.db_offset
= db
->db_blkid
* blocksize
;
2995 * Hold the dn_dbufs_mtx while we get the new dbuf
2996 * in the hash table *and* added to the dbufs list.
2997 * This prevents a possible deadlock with someone
2998 * trying to look up this dbuf before it's added to the
3001 mutex_enter(&dn
->dn_dbufs_mtx
);
3002 db
->db_state
= DB_EVICTING
; /* not worth logging this state change */
3003 if ((odb
= dbuf_hash_insert(db
)) != NULL
) {
3004 /* someone else inserted it first */
3005 kmem_cache_free(dbuf_kmem_cache
, db
);
3006 mutex_exit(&dn
->dn_dbufs_mtx
);
3007 DBUF_STAT_BUMP(hash_insert_race
);
3010 avl_add(&dn
->dn_dbufs
, db
);
3012 db
->db_state
= DB_UNCACHED
;
3013 DTRACE_SET_STATE(db
, "regular buffer created");
3014 db
->db_caching_status
= DB_NO_CACHE
;
3015 mutex_exit(&dn
->dn_dbufs_mtx
);
3016 arc_space_consume(sizeof (dmu_buf_impl_t
), ARC_SPACE_DBUF
);
3018 if (parent
&& parent
!= dn
->dn_dbuf
)
3019 dbuf_add_ref(parent
, db
);
3021 ASSERT(dn
->dn_object
== DMU_META_DNODE_OBJECT
||
3022 zfs_refcount_count(&dn
->dn_holds
) > 0);
3023 (void) zfs_refcount_add(&dn
->dn_holds
, db
);
3025 dprintf_dbuf(db
, "db=%p\n", db
);
3031 * This function returns a block pointer and information about the object,
3032 * given a dnode and a block. This is a publicly accessible version of
3033 * dbuf_findbp that only returns some information, rather than the
3034 * dbuf. Note that the dnode passed in must be held, and the dn_struct_rwlock
3035 * should be locked as (at least) a reader.
3038 dbuf_dnode_findbp(dnode_t
*dn
, uint64_t level
, uint64_t blkid
,
3039 blkptr_t
*bp
, uint16_t *datablkszsec
, uint8_t *indblkshift
)
3041 dmu_buf_impl_t
*dbp
= NULL
;
3044 ASSERT(RW_LOCK_HELD(&dn
->dn_struct_rwlock
));
3046 err
= dbuf_findbp(dn
, level
, blkid
, B_FALSE
, &dbp
, &bp2
);
3050 dbuf_rele(dbp
, NULL
);
3051 if (datablkszsec
!= NULL
)
3052 *datablkszsec
= dn
->dn_phys
->dn_datablkszsec
;
3053 if (indblkshift
!= NULL
)
3054 *indblkshift
= dn
->dn_phys
->dn_indblkshift
;
3060 typedef struct dbuf_prefetch_arg
{
3061 spa_t
*dpa_spa
; /* The spa to issue the prefetch in. */
3062 zbookmark_phys_t dpa_zb
; /* The target block to prefetch. */
3063 int dpa_epbs
; /* Entries (blkptr_t's) Per Block Shift. */
3064 int dpa_curlevel
; /* The current level that we're reading */
3065 dnode_t
*dpa_dnode
; /* The dnode associated with the prefetch */
3066 zio_priority_t dpa_prio
; /* The priority I/Os should be issued at. */
3067 zio_t
*dpa_zio
; /* The parent zio_t for all prefetches. */
3068 arc_flags_t dpa_aflags
; /* Flags to pass to the final prefetch. */
3069 dbuf_prefetch_fn dpa_cb
; /* prefetch completion callback */
3070 void *dpa_arg
; /* prefetch completion arg */
3071 } dbuf_prefetch_arg_t
;
3074 dbuf_prefetch_fini(dbuf_prefetch_arg_t
*dpa
, boolean_t io_done
)
3076 if (dpa
->dpa_cb
!= NULL
)
3077 dpa
->dpa_cb(dpa
->dpa_arg
, io_done
);
3078 kmem_free(dpa
, sizeof (*dpa
));
3082 dbuf_issue_final_prefetch_done(zio_t
*zio
, const zbookmark_phys_t
*zb
,
3083 const blkptr_t
*iobp
, arc_buf_t
*abuf
, void *private)
3085 dbuf_prefetch_arg_t
*dpa
= private;
3087 dbuf_prefetch_fini(dpa
, B_TRUE
);
3089 arc_buf_destroy(abuf
, private);
3093 * Actually issue the prefetch read for the block given.
3096 dbuf_issue_final_prefetch(dbuf_prefetch_arg_t
*dpa
, blkptr_t
*bp
)
3098 ASSERT(!BP_IS_REDACTED(bp
) ||
3099 dsl_dataset_feature_is_active(
3100 dpa
->dpa_dnode
->dn_objset
->os_dsl_dataset
,
3101 SPA_FEATURE_REDACTED_DATASETS
));
3103 if (BP_IS_HOLE(bp
) || BP_IS_EMBEDDED(bp
) || BP_IS_REDACTED(bp
))
3104 return (dbuf_prefetch_fini(dpa
, B_FALSE
));
3106 int zio_flags
= ZIO_FLAG_CANFAIL
| ZIO_FLAG_SPECULATIVE
;
3107 arc_flags_t aflags
=
3108 dpa
->dpa_aflags
| ARC_FLAG_NOWAIT
| ARC_FLAG_PREFETCH
|
3111 /* dnodes are always read as raw and then converted later */
3112 if (BP_GET_TYPE(bp
) == DMU_OT_DNODE
&& BP_IS_PROTECTED(bp
) &&
3113 dpa
->dpa_curlevel
== 0)
3114 zio_flags
|= ZIO_FLAG_RAW
;
3116 ASSERT3U(dpa
->dpa_curlevel
, ==, BP_GET_LEVEL(bp
));
3117 ASSERT3U(dpa
->dpa_curlevel
, ==, dpa
->dpa_zb
.zb_level
);
3118 ASSERT(dpa
->dpa_zio
!= NULL
);
3119 (void) arc_read(dpa
->dpa_zio
, dpa
->dpa_spa
, bp
,
3120 dbuf_issue_final_prefetch_done
, dpa
,
3121 dpa
->dpa_prio
, zio_flags
, &aflags
, &dpa
->dpa_zb
);
3125 * Called when an indirect block above our prefetch target is read in. This
3126 * will either read in the next indirect block down the tree or issue the actual
3127 * prefetch if the next block down is our target.
3130 dbuf_prefetch_indirect_done(zio_t
*zio
, const zbookmark_phys_t
*zb
,
3131 const blkptr_t
*iobp
, arc_buf_t
*abuf
, void *private)
3133 dbuf_prefetch_arg_t
*dpa
= private;
3135 ASSERT3S(dpa
->dpa_zb
.zb_level
, <, dpa
->dpa_curlevel
);
3136 ASSERT3S(dpa
->dpa_curlevel
, >, 0);
3139 ASSERT(zio
== NULL
|| zio
->io_error
!= 0);
3140 return (dbuf_prefetch_fini(dpa
, B_TRUE
));
3142 ASSERT(zio
== NULL
|| zio
->io_error
== 0);
3145 * The dpa_dnode is only valid if we are called with a NULL
3146 * zio. This indicates that the arc_read() returned without
3147 * first calling zio_read() to issue a physical read. Once
3148 * a physical read is made the dpa_dnode must be invalidated
3149 * as the locks guarding it may have been dropped. If the
3150 * dpa_dnode is still valid, then we want to add it to the dbuf
3151 * cache. To do so, we must hold the dbuf associated with the block
3152 * we just prefetched, read its contents so that we associate it
3153 * with an arc_buf_t, and then release it.
3156 ASSERT3S(BP_GET_LEVEL(zio
->io_bp
), ==, dpa
->dpa_curlevel
);
3157 if (zio
->io_flags
& ZIO_FLAG_RAW_COMPRESS
) {
3158 ASSERT3U(BP_GET_PSIZE(zio
->io_bp
), ==, zio
->io_size
);
3160 ASSERT3U(BP_GET_LSIZE(zio
->io_bp
), ==, zio
->io_size
);
3162 ASSERT3P(zio
->io_spa
, ==, dpa
->dpa_spa
);
3164 dpa
->dpa_dnode
= NULL
;
3165 } else if (dpa
->dpa_dnode
!= NULL
) {
3166 uint64_t curblkid
= dpa
->dpa_zb
.zb_blkid
>>
3167 (dpa
->dpa_epbs
* (dpa
->dpa_curlevel
-
3168 dpa
->dpa_zb
.zb_level
));
3169 dmu_buf_impl_t
*db
= dbuf_hold_level(dpa
->dpa_dnode
,
3170 dpa
->dpa_curlevel
, curblkid
, FTAG
);
3172 arc_buf_destroy(abuf
, private);
3173 return (dbuf_prefetch_fini(dpa
, B_TRUE
));
3175 (void) dbuf_read(db
, NULL
,
3176 DB_RF_MUST_SUCCEED
| DB_RF_NOPREFETCH
| DB_RF_HAVESTRUCT
);
3177 dbuf_rele(db
, FTAG
);
3180 dpa
->dpa_curlevel
--;
3181 uint64_t nextblkid
= dpa
->dpa_zb
.zb_blkid
>>
3182 (dpa
->dpa_epbs
* (dpa
->dpa_curlevel
- dpa
->dpa_zb
.zb_level
));
3183 blkptr_t
*bp
= ((blkptr_t
*)abuf
->b_data
) +
3184 P2PHASE(nextblkid
, 1ULL << dpa
->dpa_epbs
);
3186 ASSERT(!BP_IS_REDACTED(bp
) ||
3187 dsl_dataset_feature_is_active(
3188 dpa
->dpa_dnode
->dn_objset
->os_dsl_dataset
,
3189 SPA_FEATURE_REDACTED_DATASETS
));
3190 if (BP_IS_HOLE(bp
) || BP_IS_REDACTED(bp
)) {
3191 dbuf_prefetch_fini(dpa
, B_TRUE
);
3192 } else if (dpa
->dpa_curlevel
== dpa
->dpa_zb
.zb_level
) {
3193 ASSERT3U(nextblkid
, ==, dpa
->dpa_zb
.zb_blkid
);
3194 dbuf_issue_final_prefetch(dpa
, bp
);
3196 arc_flags_t iter_aflags
= ARC_FLAG_NOWAIT
;
3197 zbookmark_phys_t zb
;
3199 /* flag if L2ARC eligible, l2arc_noprefetch then decides */
3200 if (dpa
->dpa_aflags
& ARC_FLAG_L2CACHE
)
3201 iter_aflags
|= ARC_FLAG_L2CACHE
;
3203 ASSERT3U(dpa
->dpa_curlevel
, ==, BP_GET_LEVEL(bp
));
3205 SET_BOOKMARK(&zb
, dpa
->dpa_zb
.zb_objset
,
3206 dpa
->dpa_zb
.zb_object
, dpa
->dpa_curlevel
, nextblkid
);
3208 (void) arc_read(dpa
->dpa_zio
, dpa
->dpa_spa
,
3209 bp
, dbuf_prefetch_indirect_done
, dpa
, dpa
->dpa_prio
,
3210 ZIO_FLAG_CANFAIL
| ZIO_FLAG_SPECULATIVE
,
3214 arc_buf_destroy(abuf
, private);
3218 * Issue prefetch reads for the given block on the given level. If the indirect
3219 * blocks above that block are not in memory, we will read them in
3220 * asynchronously. As a result, this call never blocks waiting for a read to
3221 * complete. Note that the prefetch might fail if the dataset is encrypted and
3222 * the encryption key is unmapped before the IO completes.
3225 dbuf_prefetch_impl(dnode_t
*dn
, int64_t level
, uint64_t blkid
,
3226 zio_priority_t prio
, arc_flags_t aflags
, dbuf_prefetch_fn cb
,
3230 int epbs
, nlevels
, curlevel
;
3233 ASSERT(blkid
!= DMU_BONUS_BLKID
);
3234 ASSERT(RW_LOCK_HELD(&dn
->dn_struct_rwlock
));
3236 if (blkid
> dn
->dn_maxblkid
)
3239 if (level
== 0 && dnode_block_freed(dn
, blkid
))
3243 * This dnode hasn't been written to disk yet, so there's nothing to
3246 nlevels
= dn
->dn_phys
->dn_nlevels
;
3247 if (level
>= nlevels
|| dn
->dn_phys
->dn_nblkptr
== 0)
3250 epbs
= dn
->dn_phys
->dn_indblkshift
- SPA_BLKPTRSHIFT
;
3251 if (dn
->dn_phys
->dn_maxblkid
< blkid
<< (epbs
* level
))
3254 dmu_buf_impl_t
*db
= dbuf_find(dn
->dn_objset
, dn
->dn_object
,
3257 mutex_exit(&db
->db_mtx
);
3259 * This dbuf already exists. It is either CACHED, or
3260 * (we assume) about to be read or filled.
3266 * Find the closest ancestor (indirect block) of the target block
3267 * that is present in the cache. In this indirect block, we will
3268 * find the bp that is at curlevel, curblkid.
3272 while (curlevel
< nlevels
- 1) {
3273 int parent_level
= curlevel
+ 1;
3274 uint64_t parent_blkid
= curblkid
>> epbs
;
3277 if (dbuf_hold_impl(dn
, parent_level
, parent_blkid
,
3278 FALSE
, TRUE
, FTAG
, &db
) == 0) {
3279 blkptr_t
*bpp
= db
->db_buf
->b_data
;
3280 bp
= bpp
[P2PHASE(curblkid
, 1 << epbs
)];
3281 dbuf_rele(db
, FTAG
);
3285 curlevel
= parent_level
;
3286 curblkid
= parent_blkid
;
3289 if (curlevel
== nlevels
- 1) {
3290 /* No cached indirect blocks found. */
3291 ASSERT3U(curblkid
, <, dn
->dn_phys
->dn_nblkptr
);
3292 bp
= dn
->dn_phys
->dn_blkptr
[curblkid
];
3294 ASSERT(!BP_IS_REDACTED(&bp
) ||
3295 dsl_dataset_feature_is_active(dn
->dn_objset
->os_dsl_dataset
,
3296 SPA_FEATURE_REDACTED_DATASETS
));
3297 if (BP_IS_HOLE(&bp
) || BP_IS_REDACTED(&bp
))
3300 ASSERT3U(curlevel
, ==, BP_GET_LEVEL(&bp
));
3302 zio_t
*pio
= zio_root(dmu_objset_spa(dn
->dn_objset
), NULL
, NULL
,
3305 dbuf_prefetch_arg_t
*dpa
= kmem_zalloc(sizeof (*dpa
), KM_SLEEP
);
3306 dsl_dataset_t
*ds
= dn
->dn_objset
->os_dsl_dataset
;
3307 SET_BOOKMARK(&dpa
->dpa_zb
, ds
!= NULL
? ds
->ds_object
: DMU_META_OBJSET
,
3308 dn
->dn_object
, level
, blkid
);
3309 dpa
->dpa_curlevel
= curlevel
;
3310 dpa
->dpa_prio
= prio
;
3311 dpa
->dpa_aflags
= aflags
;
3312 dpa
->dpa_spa
= dn
->dn_objset
->os_spa
;
3313 dpa
->dpa_dnode
= dn
;
3314 dpa
->dpa_epbs
= epbs
;
3319 /* flag if L2ARC eligible, l2arc_noprefetch then decides */
3320 if (DNODE_LEVEL_IS_L2CACHEABLE(dn
, level
))
3321 dpa
->dpa_aflags
|= ARC_FLAG_L2CACHE
;
3324 * If we have the indirect just above us, no need to do the asynchronous
3325 * prefetch chain; we'll just run the last step ourselves. If we're at
3326 * a higher level, though, we want to issue the prefetches for all the
3327 * indirect blocks asynchronously, so we can go on with whatever we were
3330 if (curlevel
== level
) {
3331 ASSERT3U(curblkid
, ==, blkid
);
3332 dbuf_issue_final_prefetch(dpa
, &bp
);
3334 arc_flags_t iter_aflags
= ARC_FLAG_NOWAIT
;
3335 zbookmark_phys_t zb
;
3337 /* flag if L2ARC eligible, l2arc_noprefetch then decides */
3338 if (DNODE_LEVEL_IS_L2CACHEABLE(dn
, level
))
3339 iter_aflags
|= ARC_FLAG_L2CACHE
;
3341 SET_BOOKMARK(&zb
, ds
!= NULL
? ds
->ds_object
: DMU_META_OBJSET
,
3342 dn
->dn_object
, curlevel
, curblkid
);
3343 (void) arc_read(dpa
->dpa_zio
, dpa
->dpa_spa
,
3344 &bp
, dbuf_prefetch_indirect_done
, dpa
, prio
,
3345 ZIO_FLAG_CANFAIL
| ZIO_FLAG_SPECULATIVE
,
3349 * We use pio here instead of dpa_zio since it's possible that
3350 * dpa may have already been freed.
3361 dbuf_prefetch(dnode_t
*dn
, int64_t level
, uint64_t blkid
, zio_priority_t prio
,
3365 return (dbuf_prefetch_impl(dn
, level
, blkid
, prio
, aflags
, NULL
, NULL
));
3369 * Helper function for dbuf_hold_impl() to copy a buffer. Handles
3370 * the case of encrypted, compressed and uncompressed buffers by
3371 * allocating the new buffer, respectively, with arc_alloc_raw_buf(),
3372 * arc_alloc_compressed_buf() or arc_alloc_buf().*
3374 * NOTE: Declared noinline to avoid stack bloat in dbuf_hold_impl().
3376 noinline
static void
3377 dbuf_hold_copy(dnode_t
*dn
, dmu_buf_impl_t
*db
)
3379 dbuf_dirty_record_t
*dr
= db
->db_data_pending
;
3380 arc_buf_t
*newdata
, *data
= dr
->dt
.dl
.dr_data
;
3382 newdata
= dbuf_alloc_arcbuf_from_arcbuf(db
, data
);
3383 dbuf_set_data(db
, newdata
);
3384 rw_enter(&db
->db_rwlock
, RW_WRITER
);
3385 bcopy(data
->b_data
, db
->db
.db_data
, arc_buf_size(data
));
3386 rw_exit(&db
->db_rwlock
);
3390 * Returns with db_holds incremented, and db_mtx not held.
3391 * Note: dn_struct_rwlock must be held.
3394 dbuf_hold_impl(dnode_t
*dn
, uint8_t level
, uint64_t blkid
,
3395 boolean_t fail_sparse
, boolean_t fail_uncached
,
3396 void *tag
, dmu_buf_impl_t
**dbp
)
3398 dmu_buf_impl_t
*db
, *parent
= NULL
;
3400 /* If the pool has been created, verify the tx_sync_lock is not held */
3401 spa_t
*spa
= dn
->dn_objset
->os_spa
;
3402 dsl_pool_t
*dp
= spa
->spa_dsl_pool
;
3404 ASSERT(!MUTEX_HELD(&dp
->dp_tx
.tx_sync_lock
));
3407 ASSERT(blkid
!= DMU_BONUS_BLKID
);
3408 ASSERT(RW_LOCK_HELD(&dn
->dn_struct_rwlock
));
3409 ASSERT3U(dn
->dn_nlevels
, >, level
);
3413 /* dbuf_find() returns with db_mtx held */
3414 db
= dbuf_find(dn
->dn_objset
, dn
->dn_object
, level
, blkid
);
3417 blkptr_t
*bp
= NULL
;
3421 return (SET_ERROR(ENOENT
));
3423 ASSERT3P(parent
, ==, NULL
);
3424 err
= dbuf_findbp(dn
, level
, blkid
, fail_sparse
, &parent
, &bp
);
3426 if (err
== 0 && bp
&& BP_IS_HOLE(bp
))
3427 err
= SET_ERROR(ENOENT
);
3430 dbuf_rele(parent
, NULL
);
3434 if (err
&& err
!= ENOENT
)
3436 db
= dbuf_create(dn
, level
, blkid
, parent
, bp
);
3439 if (fail_uncached
&& db
->db_state
!= DB_CACHED
) {
3440 mutex_exit(&db
->db_mtx
);
3441 return (SET_ERROR(ENOENT
));
3444 if (db
->db_buf
!= NULL
) {
3445 arc_buf_access(db
->db_buf
);
3446 ASSERT3P(db
->db
.db_data
, ==, db
->db_buf
->b_data
);
3449 ASSERT(db
->db_buf
== NULL
|| arc_referenced(db
->db_buf
));
3452 * If this buffer is currently syncing out, and we are
3453 * still referencing it from db_data, we need to make a copy
3454 * of it in case we decide we want to dirty it again in this txg.
3456 if (db
->db_level
== 0 && db
->db_blkid
!= DMU_BONUS_BLKID
&&
3457 dn
->dn_object
!= DMU_META_DNODE_OBJECT
&&
3458 db
->db_state
== DB_CACHED
&& db
->db_data_pending
) {
3459 dbuf_dirty_record_t
*dr
= db
->db_data_pending
;
3460 if (dr
->dt
.dl
.dr_data
== db
->db_buf
)
3461 dbuf_hold_copy(dn
, db
);
3464 if (multilist_link_active(&db
->db_cache_link
)) {
3465 ASSERT(zfs_refcount_is_zero(&db
->db_holds
));
3466 ASSERT(db
->db_caching_status
== DB_DBUF_CACHE
||
3467 db
->db_caching_status
== DB_DBUF_METADATA_CACHE
);
3469 multilist_remove(dbuf_caches
[db
->db_caching_status
].cache
, db
);
3470 (void) zfs_refcount_remove_many(
3471 &dbuf_caches
[db
->db_caching_status
].size
,
3472 db
->db
.db_size
, db
);
3474 if (db
->db_caching_status
== DB_DBUF_METADATA_CACHE
) {
3475 DBUF_STAT_BUMPDOWN(metadata_cache_count
);
3477 DBUF_STAT_BUMPDOWN(cache_levels
[db
->db_level
]);
3478 DBUF_STAT_BUMPDOWN(cache_count
);
3479 DBUF_STAT_DECR(cache_levels_bytes
[db
->db_level
],
3482 db
->db_caching_status
= DB_NO_CACHE
;
3484 (void) zfs_refcount_add(&db
->db_holds
, tag
);
3486 mutex_exit(&db
->db_mtx
);
3488 /* NOTE: we can't rele the parent until after we drop the db_mtx */
3490 dbuf_rele(parent
, NULL
);
3492 ASSERT3P(DB_DNODE(db
), ==, dn
);
3493 ASSERT3U(db
->db_blkid
, ==, blkid
);
3494 ASSERT3U(db
->db_level
, ==, level
);
3501 dbuf_hold(dnode_t
*dn
, uint64_t blkid
, void *tag
)
3503 return (dbuf_hold_level(dn
, 0, blkid
, tag
));
3507 dbuf_hold_level(dnode_t
*dn
, int level
, uint64_t blkid
, void *tag
)
3510 int err
= dbuf_hold_impl(dn
, level
, blkid
, FALSE
, FALSE
, tag
, &db
);
3511 return (err
? NULL
: db
);
3515 dbuf_create_bonus(dnode_t
*dn
)
3517 ASSERT(RW_WRITE_HELD(&dn
->dn_struct_rwlock
));
3519 ASSERT(dn
->dn_bonus
== NULL
);
3520 dn
->dn_bonus
= dbuf_create(dn
, 0, DMU_BONUS_BLKID
, dn
->dn_dbuf
, NULL
);
3524 dbuf_spill_set_blksz(dmu_buf_t
*db_fake
, uint64_t blksz
, dmu_tx_t
*tx
)
3526 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)db_fake
;
3528 if (db
->db_blkid
!= DMU_SPILL_BLKID
)
3529 return (SET_ERROR(ENOTSUP
));
3531 blksz
= SPA_MINBLOCKSIZE
;
3532 ASSERT3U(blksz
, <=, spa_maxblocksize(dmu_objset_spa(db
->db_objset
)));
3533 blksz
= P2ROUNDUP(blksz
, SPA_MINBLOCKSIZE
);
3535 dbuf_new_size(db
, blksz
, tx
);
3541 dbuf_rm_spill(dnode_t
*dn
, dmu_tx_t
*tx
)
3543 dbuf_free_range(dn
, DMU_SPILL_BLKID
, DMU_SPILL_BLKID
, tx
);
3546 #pragma weak dmu_buf_add_ref = dbuf_add_ref
3548 dbuf_add_ref(dmu_buf_impl_t
*db
, void *tag
)
3550 int64_t holds
= zfs_refcount_add(&db
->db_holds
, tag
);
3551 VERIFY3S(holds
, >, 1);
3554 #pragma weak dmu_buf_try_add_ref = dbuf_try_add_ref
3556 dbuf_try_add_ref(dmu_buf_t
*db_fake
, objset_t
*os
, uint64_t obj
, uint64_t blkid
,
3559 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)db_fake
;
3560 dmu_buf_impl_t
*found_db
;
3561 boolean_t result
= B_FALSE
;
3563 if (blkid
== DMU_BONUS_BLKID
)
3564 found_db
= dbuf_find_bonus(os
, obj
);
3566 found_db
= dbuf_find(os
, obj
, 0, blkid
);
3568 if (found_db
!= NULL
) {
3569 if (db
== found_db
&& dbuf_refcount(db
) > db
->db_dirtycnt
) {
3570 (void) zfs_refcount_add(&db
->db_holds
, tag
);
3573 mutex_exit(&found_db
->db_mtx
);
3579 * If you call dbuf_rele() you had better not be referencing the dnode handle
3580 * unless you have some other direct or indirect hold on the dnode. (An indirect
3581 * hold is a hold on one of the dnode's dbufs, including the bonus buffer.)
3582 * Without that, the dbuf_rele() could lead to a dnode_rele() followed by the
3583 * dnode's parent dbuf evicting its dnode handles.
3586 dbuf_rele(dmu_buf_impl_t
*db
, void *tag
)
3588 mutex_enter(&db
->db_mtx
);
3589 dbuf_rele_and_unlock(db
, tag
, B_FALSE
);
3593 dmu_buf_rele(dmu_buf_t
*db
, void *tag
)
3595 dbuf_rele((dmu_buf_impl_t
*)db
, tag
);
3599 * dbuf_rele() for an already-locked dbuf. This is necessary to allow
3600 * db_dirtycnt and db_holds to be updated atomically. The 'evicting'
3601 * argument should be set if we are already in the dbuf-evicting code
3602 * path, in which case we don't want to recursively evict. This allows us to
3603 * avoid deeply nested stacks that would have a call flow similar to this:
3605 * dbuf_rele()-->dbuf_rele_and_unlock()-->dbuf_evict_notify()
3608 * +-----dbuf_destroy()<--dbuf_evict_one()<--------+
3612 dbuf_rele_and_unlock(dmu_buf_impl_t
*db
, void *tag
, boolean_t evicting
)
3617 ASSERT(MUTEX_HELD(&db
->db_mtx
));
3621 * Remove the reference to the dbuf before removing its hold on the
3622 * dnode so we can guarantee in dnode_move() that a referenced bonus
3623 * buffer has a corresponding dnode hold.
3625 holds
= zfs_refcount_remove(&db
->db_holds
, tag
);
3629 * We can't freeze indirects if there is a possibility that they
3630 * may be modified in the current syncing context.
3632 if (db
->db_buf
!= NULL
&&
3633 holds
== (db
->db_level
== 0 ? db
->db_dirtycnt
: 0)) {
3634 arc_buf_freeze(db
->db_buf
);
3637 if (holds
== db
->db_dirtycnt
&&
3638 db
->db_level
== 0 && db
->db_user_immediate_evict
)
3639 dbuf_evict_user(db
);
3642 if (db
->db_blkid
== DMU_BONUS_BLKID
) {
3644 boolean_t evict_dbuf
= db
->db_pending_evict
;
3647 * If the dnode moves here, we cannot cross this
3648 * barrier until the move completes.
3653 atomic_dec_32(&dn
->dn_dbufs_count
);
3656 * Decrementing the dbuf count means that the bonus
3657 * buffer's dnode hold is no longer discounted in
3658 * dnode_move(). The dnode cannot move until after
3659 * the dnode_rele() below.
3664 * Do not reference db after its lock is dropped.
3665 * Another thread may evict it.
3667 mutex_exit(&db
->db_mtx
);
3670 dnode_evict_bonus(dn
);
3673 } else if (db
->db_buf
== NULL
) {
3675 * This is a special case: we never associated this
3676 * dbuf with any data allocated from the ARC.
3678 ASSERT(db
->db_state
== DB_UNCACHED
||
3679 db
->db_state
== DB_NOFILL
);
3681 } else if (arc_released(db
->db_buf
)) {
3683 * This dbuf has anonymous data associated with it.
3687 boolean_t do_arc_evict
= B_FALSE
;
3689 spa_t
*spa
= dmu_objset_spa(db
->db_objset
);
3691 if (!DBUF_IS_CACHEABLE(db
) &&
3692 db
->db_blkptr
!= NULL
&&
3693 !BP_IS_HOLE(db
->db_blkptr
) &&
3694 !BP_IS_EMBEDDED(db
->db_blkptr
)) {
3695 do_arc_evict
= B_TRUE
;
3696 bp
= *db
->db_blkptr
;
3699 if (!DBUF_IS_CACHEABLE(db
) ||
3700 db
->db_pending_evict
) {
3702 } else if (!multilist_link_active(&db
->db_cache_link
)) {
3703 ASSERT3U(db
->db_caching_status
, ==,
3706 dbuf_cached_state_t dcs
=
3707 dbuf_include_in_metadata_cache(db
) ?
3708 DB_DBUF_METADATA_CACHE
: DB_DBUF_CACHE
;
3709 db
->db_caching_status
= dcs
;
3711 multilist_insert(dbuf_caches
[dcs
].cache
, db
);
3712 size
= zfs_refcount_add_many(
3713 &dbuf_caches
[dcs
].size
,
3714 db
->db
.db_size
, db
);
3716 if (dcs
== DB_DBUF_METADATA_CACHE
) {
3717 DBUF_STAT_BUMP(metadata_cache_count
);
3719 metadata_cache_size_bytes_max
,
3723 cache_levels
[db
->db_level
]);
3724 DBUF_STAT_BUMP(cache_count
);
3726 cache_levels_bytes
[db
->db_level
],
3728 DBUF_STAT_MAX(cache_size_bytes_max
,
3731 mutex_exit(&db
->db_mtx
);
3733 if (dcs
== DB_DBUF_CACHE
&& !evicting
)
3734 dbuf_evict_notify(size
);
3738 arc_freed(spa
, &bp
);
3741 mutex_exit(&db
->db_mtx
);
3746 #pragma weak dmu_buf_refcount = dbuf_refcount
3748 dbuf_refcount(dmu_buf_impl_t
*db
)
3750 return (zfs_refcount_count(&db
->db_holds
));
3754 dmu_buf_user_refcount(dmu_buf_t
*db_fake
)
3757 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)db_fake
;
3759 mutex_enter(&db
->db_mtx
);
3760 ASSERT3U(zfs_refcount_count(&db
->db_holds
), >=, db
->db_dirtycnt
);
3761 holds
= zfs_refcount_count(&db
->db_holds
) - db
->db_dirtycnt
;
3762 mutex_exit(&db
->db_mtx
);
3768 dmu_buf_replace_user(dmu_buf_t
*db_fake
, dmu_buf_user_t
*old_user
,
3769 dmu_buf_user_t
*new_user
)
3771 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)db_fake
;
3773 mutex_enter(&db
->db_mtx
);
3774 dbuf_verify_user(db
, DBVU_NOT_EVICTING
);
3775 if (db
->db_user
== old_user
)
3776 db
->db_user
= new_user
;
3778 old_user
= db
->db_user
;
3779 dbuf_verify_user(db
, DBVU_NOT_EVICTING
);
3780 mutex_exit(&db
->db_mtx
);
3786 dmu_buf_set_user(dmu_buf_t
*db_fake
, dmu_buf_user_t
*user
)
3788 return (dmu_buf_replace_user(db_fake
, NULL
, user
));
3792 dmu_buf_set_user_ie(dmu_buf_t
*db_fake
, dmu_buf_user_t
*user
)
3794 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)db_fake
;
3796 db
->db_user_immediate_evict
= TRUE
;
3797 return (dmu_buf_set_user(db_fake
, user
));
3801 dmu_buf_remove_user(dmu_buf_t
*db_fake
, dmu_buf_user_t
*user
)
3803 return (dmu_buf_replace_user(db_fake
, user
, NULL
));
3807 dmu_buf_get_user(dmu_buf_t
*db_fake
)
3809 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)db_fake
;
3811 dbuf_verify_user(db
, DBVU_NOT_EVICTING
);
3812 return (db
->db_user
);
3816 dmu_buf_user_evict_wait()
3818 taskq_wait(dbu_evict_taskq
);
3822 dmu_buf_get_blkptr(dmu_buf_t
*db
)
3824 dmu_buf_impl_t
*dbi
= (dmu_buf_impl_t
*)db
;
3825 return (dbi
->db_blkptr
);
3829 dmu_buf_get_objset(dmu_buf_t
*db
)
3831 dmu_buf_impl_t
*dbi
= (dmu_buf_impl_t
*)db
;
3832 return (dbi
->db_objset
);
3836 dmu_buf_dnode_enter(dmu_buf_t
*db
)
3838 dmu_buf_impl_t
*dbi
= (dmu_buf_impl_t
*)db
;
3839 DB_DNODE_ENTER(dbi
);
3840 return (DB_DNODE(dbi
));
3844 dmu_buf_dnode_exit(dmu_buf_t
*db
)
3846 dmu_buf_impl_t
*dbi
= (dmu_buf_impl_t
*)db
;
3851 dbuf_check_blkptr(dnode_t
*dn
, dmu_buf_impl_t
*db
)
3853 /* ASSERT(dmu_tx_is_syncing(tx) */
3854 ASSERT(MUTEX_HELD(&db
->db_mtx
));
3856 if (db
->db_blkptr
!= NULL
)
3859 if (db
->db_blkid
== DMU_SPILL_BLKID
) {
3860 db
->db_blkptr
= DN_SPILL_BLKPTR(dn
->dn_phys
);
3861 BP_ZERO(db
->db_blkptr
);
3864 if (db
->db_level
== dn
->dn_phys
->dn_nlevels
-1) {
3866 * This buffer was allocated at a time when there was
3867 * no available blkptrs from the dnode, or it was
3868 * inappropriate to hook it in (i.e., nlevels mismatch).
3870 ASSERT(db
->db_blkid
< dn
->dn_phys
->dn_nblkptr
);
3871 ASSERT(db
->db_parent
== NULL
);
3872 db
->db_parent
= dn
->dn_dbuf
;
3873 db
->db_blkptr
= &dn
->dn_phys
->dn_blkptr
[db
->db_blkid
];
3876 dmu_buf_impl_t
*parent
= db
->db_parent
;
3877 int epbs
= dn
->dn_phys
->dn_indblkshift
- SPA_BLKPTRSHIFT
;
3879 ASSERT(dn
->dn_phys
->dn_nlevels
> 1);
3880 if (parent
== NULL
) {
3881 mutex_exit(&db
->db_mtx
);
3882 rw_enter(&dn
->dn_struct_rwlock
, RW_READER
);
3883 parent
= dbuf_hold_level(dn
, db
->db_level
+ 1,
3884 db
->db_blkid
>> epbs
, db
);
3885 rw_exit(&dn
->dn_struct_rwlock
);
3886 mutex_enter(&db
->db_mtx
);
3887 db
->db_parent
= parent
;
3889 db
->db_blkptr
= (blkptr_t
*)parent
->db
.db_data
+
3890 (db
->db_blkid
& ((1ULL << epbs
) - 1));
3896 dbuf_sync_bonus(dbuf_dirty_record_t
*dr
, dmu_tx_t
*tx
)
3898 dmu_buf_impl_t
*db
= dr
->dr_dbuf
;
3899 void *data
= dr
->dt
.dl
.dr_data
;
3901 ASSERT0(db
->db_level
);
3902 ASSERT(MUTEX_HELD(&db
->db_mtx
));
3903 ASSERT(db
->db_blkid
== DMU_BONUS_BLKID
);
3904 ASSERT(data
!= NULL
);
3906 dnode_t
*dn
= dr
->dr_dnode
;
3907 ASSERT3U(DN_MAX_BONUS_LEN(dn
->dn_phys
), <=,
3908 DN_SLOTS_TO_BONUSLEN(dn
->dn_phys
->dn_extra_slots
+ 1));
3909 bcopy(data
, DN_BONUS(dn
->dn_phys
), DN_MAX_BONUS_LEN(dn
->dn_phys
));
3911 dbuf_sync_leaf_verify_bonus_dnode(dr
);
3913 dbuf_undirty_bonus(dr
);
3914 dbuf_rele_and_unlock(db
, (void *)(uintptr_t)tx
->tx_txg
, B_FALSE
);
3918 * When syncing out a blocks of dnodes, adjust the block to deal with
3919 * encryption. Normally, we make sure the block is decrypted before writing
3920 * it. If we have crypt params, then we are writing a raw (encrypted) block,
3921 * from a raw receive. In this case, set the ARC buf's crypt params so
3922 * that the BP will be filled with the correct byteorder, salt, iv, and mac.
3925 dbuf_prepare_encrypted_dnode_leaf(dbuf_dirty_record_t
*dr
)
3928 dmu_buf_impl_t
*db
= dr
->dr_dbuf
;
3930 ASSERT(MUTEX_HELD(&db
->db_mtx
));
3931 ASSERT3U(db
->db
.db_object
, ==, DMU_META_DNODE_OBJECT
);
3932 ASSERT3U(db
->db_level
, ==, 0);
3934 if (!db
->db_objset
->os_raw_receive
&& arc_is_encrypted(db
->db_buf
)) {
3935 zbookmark_phys_t zb
;
3938 * Unfortunately, there is currently no mechanism for
3939 * syncing context to handle decryption errors. An error
3940 * here is only possible if an attacker maliciously
3941 * changed a dnode block and updated the associated
3942 * checksums going up the block tree.
3944 SET_BOOKMARK(&zb
, dmu_objset_id(db
->db_objset
),
3945 db
->db
.db_object
, db
->db_level
, db
->db_blkid
);
3946 err
= arc_untransform(db
->db_buf
, db
->db_objset
->os_spa
,
3949 panic("Invalid dnode block MAC");
3950 } else if (dr
->dt
.dl
.dr_has_raw_params
) {
3951 (void) arc_release(dr
->dt
.dl
.dr_data
, db
);
3952 arc_convert_to_raw(dr
->dt
.dl
.dr_data
,
3953 dmu_objset_id(db
->db_objset
),
3954 dr
->dt
.dl
.dr_byteorder
, DMU_OT_DNODE
,
3955 dr
->dt
.dl
.dr_salt
, dr
->dt
.dl
.dr_iv
, dr
->dt
.dl
.dr_mac
);
3960 * dbuf_sync_indirect() is called recursively from dbuf_sync_list() so it
3961 * is critical the we not allow the compiler to inline this function in to
3962 * dbuf_sync_list() thereby drastically bloating the stack usage.
3964 noinline
static void
3965 dbuf_sync_indirect(dbuf_dirty_record_t
*dr
, dmu_tx_t
*tx
)
3967 dmu_buf_impl_t
*db
= dr
->dr_dbuf
;
3968 dnode_t
*dn
= dr
->dr_dnode
;
3970 ASSERT(dmu_tx_is_syncing(tx
));
3972 dprintf_dbuf_bp(db
, db
->db_blkptr
, "blkptr=%p", db
->db_blkptr
);
3974 mutex_enter(&db
->db_mtx
);
3976 ASSERT(db
->db_level
> 0);
3979 /* Read the block if it hasn't been read yet. */
3980 if (db
->db_buf
== NULL
) {
3981 mutex_exit(&db
->db_mtx
);
3982 (void) dbuf_read(db
, NULL
, DB_RF_MUST_SUCCEED
);
3983 mutex_enter(&db
->db_mtx
);
3985 ASSERT3U(db
->db_state
, ==, DB_CACHED
);
3986 ASSERT(db
->db_buf
!= NULL
);
3988 /* Indirect block size must match what the dnode thinks it is. */
3989 ASSERT3U(db
->db
.db_size
, ==, 1<<dn
->dn_phys
->dn_indblkshift
);
3990 dbuf_check_blkptr(dn
, db
);
3992 /* Provide the pending dirty record to child dbufs */
3993 db
->db_data_pending
= dr
;
3995 mutex_exit(&db
->db_mtx
);
3997 dbuf_write(dr
, db
->db_buf
, tx
);
3999 zio_t
*zio
= dr
->dr_zio
;
4000 mutex_enter(&dr
->dt
.di
.dr_mtx
);
4001 dbuf_sync_list(&dr
->dt
.di
.dr_children
, db
->db_level
- 1, tx
);
4002 ASSERT(list_head(&dr
->dt
.di
.dr_children
) == NULL
);
4003 mutex_exit(&dr
->dt
.di
.dr_mtx
);
4008 * Verify that the size of the data in our bonus buffer does not exceed
4009 * its recorded size.
4011 * The purpose of this verification is to catch any cases in development
4012 * where the size of a phys structure (i.e space_map_phys_t) grows and,
4013 * due to incorrect feature management, older pools expect to read more
4014 * data even though they didn't actually write it to begin with.
4016 * For a example, this would catch an error in the feature logic where we
4017 * open an older pool and we expect to write the space map histogram of
4018 * a space map with size SPACE_MAP_SIZE_V0.
4021 dbuf_sync_leaf_verify_bonus_dnode(dbuf_dirty_record_t
*dr
)
4024 dnode_t
*dn
= dr
->dr_dnode
;
4027 * Encrypted bonus buffers can have data past their bonuslen.
4028 * Skip the verification of these blocks.
4030 if (DMU_OT_IS_ENCRYPTED(dn
->dn_bonustype
))
4033 uint16_t bonuslen
= dn
->dn_phys
->dn_bonuslen
;
4034 uint16_t maxbonuslen
= DN_SLOTS_TO_BONUSLEN(dn
->dn_num_slots
);
4035 ASSERT3U(bonuslen
, <=, maxbonuslen
);
4037 arc_buf_t
*datap
= dr
->dt
.dl
.dr_data
;
4038 char *datap_end
= ((char *)datap
) + bonuslen
;
4039 char *datap_max
= ((char *)datap
) + maxbonuslen
;
4041 /* ensure that everything is zero after our data */
4042 for (; datap_end
< datap_max
; datap_end
++)
4043 ASSERT(*datap_end
== 0);
4048 dbuf_lightweight_bp(dbuf_dirty_record_t
*dr
)
4050 /* This must be a lightweight dirty record. */
4051 ASSERT3P(dr
->dr_dbuf
, ==, NULL
);
4052 dnode_t
*dn
= dr
->dr_dnode
;
4054 if (dn
->dn_phys
->dn_nlevels
== 1) {
4055 VERIFY3U(dr
->dt
.dll
.dr_blkid
, <, dn
->dn_phys
->dn_nblkptr
);
4056 return (&dn
->dn_phys
->dn_blkptr
[dr
->dt
.dll
.dr_blkid
]);
4058 dmu_buf_impl_t
*parent_db
= dr
->dr_parent
->dr_dbuf
;
4059 int epbs
= dn
->dn_indblkshift
- SPA_BLKPTRSHIFT
;
4060 VERIFY3U(parent_db
->db_level
, ==, 1);
4061 VERIFY3P(parent_db
->db_dnode_handle
->dnh_dnode
, ==, dn
);
4062 VERIFY3U(dr
->dt
.dll
.dr_blkid
>> epbs
, ==, parent_db
->db_blkid
);
4063 blkptr_t
*bp
= parent_db
->db
.db_data
;
4064 return (&bp
[dr
->dt
.dll
.dr_blkid
& ((1 << epbs
) - 1)]);
4069 dbuf_lightweight_ready(zio_t
*zio
)
4071 dbuf_dirty_record_t
*dr
= zio
->io_private
;
4072 blkptr_t
*bp
= zio
->io_bp
;
4074 if (zio
->io_error
!= 0)
4077 dnode_t
*dn
= dr
->dr_dnode
;
4079 blkptr_t
*bp_orig
= dbuf_lightweight_bp(dr
);
4080 spa_t
*spa
= dmu_objset_spa(dn
->dn_objset
);
4081 int64_t delta
= bp_get_dsize_sync(spa
, bp
) -
4082 bp_get_dsize_sync(spa
, bp_orig
);
4083 dnode_diduse_space(dn
, delta
);
4085 uint64_t blkid
= dr
->dt
.dll
.dr_blkid
;
4086 mutex_enter(&dn
->dn_mtx
);
4087 if (blkid
> dn
->dn_phys
->dn_maxblkid
) {
4088 ASSERT0(dn
->dn_objset
->os_raw_receive
);
4089 dn
->dn_phys
->dn_maxblkid
= blkid
;
4091 mutex_exit(&dn
->dn_mtx
);
4093 if (!BP_IS_EMBEDDED(bp
)) {
4094 uint64_t fill
= BP_IS_HOLE(bp
) ? 0 : 1;
4095 BP_SET_FILL(bp
, fill
);
4098 dmu_buf_impl_t
*parent_db
;
4099 EQUIV(dr
->dr_parent
== NULL
, dn
->dn_phys
->dn_nlevels
== 1);
4100 if (dr
->dr_parent
== NULL
) {
4101 parent_db
= dn
->dn_dbuf
;
4103 parent_db
= dr
->dr_parent
->dr_dbuf
;
4105 rw_enter(&parent_db
->db_rwlock
, RW_WRITER
);
4107 rw_exit(&parent_db
->db_rwlock
);
4111 dbuf_lightweight_physdone(zio_t
*zio
)
4113 dbuf_dirty_record_t
*dr
= zio
->io_private
;
4114 dsl_pool_t
*dp
= spa_get_dsl(zio
->io_spa
);
4115 ASSERT3U(dr
->dr_txg
, ==, zio
->io_txg
);
4118 * The callback will be called io_phys_children times. Retire one
4119 * portion of our dirty space each time we are called. Any rounding
4120 * error will be cleaned up by dbuf_lightweight_done().
4122 int delta
= dr
->dr_accounted
/ zio
->io_phys_children
;
4123 dsl_pool_undirty_space(dp
, delta
, zio
->io_txg
);
4127 dbuf_lightweight_done(zio_t
*zio
)
4129 dbuf_dirty_record_t
*dr
= zio
->io_private
;
4131 VERIFY0(zio
->io_error
);
4133 objset_t
*os
= dr
->dr_dnode
->dn_objset
;
4134 dmu_tx_t
*tx
= os
->os_synctx
;
4136 if (zio
->io_flags
& (ZIO_FLAG_IO_REWRITE
| ZIO_FLAG_NOPWRITE
)) {
4137 ASSERT(BP_EQUAL(zio
->io_bp
, &zio
->io_bp_orig
));
4139 dsl_dataset_t
*ds
= os
->os_dsl_dataset
;
4140 (void) dsl_dataset_block_kill(ds
, &zio
->io_bp_orig
, tx
, B_TRUE
);
4141 dsl_dataset_block_born(ds
, zio
->io_bp
, tx
);
4145 * See comment in dbuf_write_done().
4147 if (zio
->io_phys_children
== 0) {
4148 dsl_pool_undirty_space(dmu_objset_pool(os
),
4149 dr
->dr_accounted
, zio
->io_txg
);
4151 dsl_pool_undirty_space(dmu_objset_pool(os
),
4152 dr
->dr_accounted
% zio
->io_phys_children
, zio
->io_txg
);
4155 abd_free(dr
->dt
.dll
.dr_abd
);
4156 kmem_free(dr
, sizeof (*dr
));
4159 noinline
static void
4160 dbuf_sync_lightweight(dbuf_dirty_record_t
*dr
, dmu_tx_t
*tx
)
4162 dnode_t
*dn
= dr
->dr_dnode
;
4164 if (dn
->dn_phys
->dn_nlevels
== 1) {
4167 pio
= dr
->dr_parent
->dr_zio
;
4170 zbookmark_phys_t zb
= {
4171 .zb_objset
= dmu_objset_id(dn
->dn_objset
),
4172 .zb_object
= dn
->dn_object
,
4174 .zb_blkid
= dr
->dt
.dll
.dr_blkid
,
4178 * See comment in dbuf_write(). This is so that zio->io_bp_orig
4179 * will have the old BP in dbuf_lightweight_done().
4181 dr
->dr_bp_copy
= *dbuf_lightweight_bp(dr
);
4183 dr
->dr_zio
= zio_write(pio
, dmu_objset_spa(dn
->dn_objset
),
4184 dmu_tx_get_txg(tx
), &dr
->dr_bp_copy
, dr
->dt
.dll
.dr_abd
,
4185 dn
->dn_datablksz
, abd_get_size(dr
->dt
.dll
.dr_abd
),
4186 &dr
->dt
.dll
.dr_props
, dbuf_lightweight_ready
, NULL
,
4187 dbuf_lightweight_physdone
, dbuf_lightweight_done
, dr
,
4188 ZIO_PRIORITY_ASYNC_WRITE
,
4189 ZIO_FLAG_MUSTSUCCEED
| dr
->dt
.dll
.dr_flags
, &zb
);
4191 zio_nowait(dr
->dr_zio
);
4195 * dbuf_sync_leaf() is called recursively from dbuf_sync_list() so it is
4196 * critical the we not allow the compiler to inline this function in to
4197 * dbuf_sync_list() thereby drastically bloating the stack usage.
4199 noinline
static void
4200 dbuf_sync_leaf(dbuf_dirty_record_t
*dr
, dmu_tx_t
*tx
)
4202 arc_buf_t
**datap
= &dr
->dt
.dl
.dr_data
;
4203 dmu_buf_impl_t
*db
= dr
->dr_dbuf
;
4204 dnode_t
*dn
= dr
->dr_dnode
;
4206 uint64_t txg
= tx
->tx_txg
;
4208 ASSERT(dmu_tx_is_syncing(tx
));
4210 dprintf_dbuf_bp(db
, db
->db_blkptr
, "blkptr=%p", db
->db_blkptr
);
4212 mutex_enter(&db
->db_mtx
);
4214 * To be synced, we must be dirtied. But we
4215 * might have been freed after the dirty.
4217 if (db
->db_state
== DB_UNCACHED
) {
4218 /* This buffer has been freed since it was dirtied */
4219 ASSERT(db
->db
.db_data
== NULL
);
4220 } else if (db
->db_state
== DB_FILL
) {
4221 /* This buffer was freed and is now being re-filled */
4222 ASSERT(db
->db
.db_data
!= dr
->dt
.dl
.dr_data
);
4224 ASSERT(db
->db_state
== DB_CACHED
|| db
->db_state
== DB_NOFILL
);
4228 if (db
->db_blkid
== DMU_SPILL_BLKID
) {
4229 mutex_enter(&dn
->dn_mtx
);
4230 if (!(dn
->dn_phys
->dn_flags
& DNODE_FLAG_SPILL_BLKPTR
)) {
4232 * In the previous transaction group, the bonus buffer
4233 * was entirely used to store the attributes for the
4234 * dnode which overrode the dn_spill field. However,
4235 * when adding more attributes to the file a spill
4236 * block was required to hold the extra attributes.
4238 * Make sure to clear the garbage left in the dn_spill
4239 * field from the previous attributes in the bonus
4240 * buffer. Otherwise, after writing out the spill
4241 * block to the new allocated dva, it will free
4242 * the old block pointed to by the invalid dn_spill.
4244 db
->db_blkptr
= NULL
;
4246 dn
->dn_phys
->dn_flags
|= DNODE_FLAG_SPILL_BLKPTR
;
4247 mutex_exit(&dn
->dn_mtx
);
4251 * If this is a bonus buffer, simply copy the bonus data into the
4252 * dnode. It will be written out when the dnode is synced (and it
4253 * will be synced, since it must have been dirty for dbuf_sync to
4256 if (db
->db_blkid
== DMU_BONUS_BLKID
) {
4257 ASSERT(dr
->dr_dbuf
== db
);
4258 dbuf_sync_bonus(dr
, tx
);
4265 * This function may have dropped the db_mtx lock allowing a dmu_sync
4266 * operation to sneak in. As a result, we need to ensure that we
4267 * don't check the dr_override_state until we have returned from
4268 * dbuf_check_blkptr.
4270 dbuf_check_blkptr(dn
, db
);
4273 * If this buffer is in the middle of an immediate write,
4274 * wait for the synchronous IO to complete.
4276 while (dr
->dt
.dl
.dr_override_state
== DR_IN_DMU_SYNC
) {
4277 ASSERT(dn
->dn_object
!= DMU_META_DNODE_OBJECT
);
4278 cv_wait(&db
->db_changed
, &db
->db_mtx
);
4279 ASSERT(dr
->dt
.dl
.dr_override_state
!= DR_NOT_OVERRIDDEN
);
4283 * If this is a dnode block, ensure it is appropriately encrypted
4284 * or decrypted, depending on what we are writing to it this txg.
4286 if (os
->os_encrypted
&& dn
->dn_object
== DMU_META_DNODE_OBJECT
)
4287 dbuf_prepare_encrypted_dnode_leaf(dr
);
4289 if (db
->db_state
!= DB_NOFILL
&&
4290 dn
->dn_object
!= DMU_META_DNODE_OBJECT
&&
4291 zfs_refcount_count(&db
->db_holds
) > 1 &&
4292 dr
->dt
.dl
.dr_override_state
!= DR_OVERRIDDEN
&&
4293 *datap
== db
->db_buf
) {
4295 * If this buffer is currently "in use" (i.e., there
4296 * are active holds and db_data still references it),
4297 * then make a copy before we start the write so that
4298 * any modifications from the open txg will not leak
4301 * NOTE: this copy does not need to be made for
4302 * objects only modified in the syncing context (e.g.
4303 * DNONE_DNODE blocks).
4305 *datap
= dbuf_alloc_arcbuf_from_arcbuf(db
, db
->db_buf
);
4306 bcopy(db
->db
.db_data
, (*datap
)->b_data
, arc_buf_size(*datap
));
4308 db
->db_data_pending
= dr
;
4310 mutex_exit(&db
->db_mtx
);
4312 dbuf_write(dr
, *datap
, tx
);
4314 ASSERT(!list_link_active(&dr
->dr_dirty_node
));
4315 if (dn
->dn_object
== DMU_META_DNODE_OBJECT
) {
4316 list_insert_tail(&dn
->dn_dirty_records
[txg
& TXG_MASK
], dr
);
4318 zio_nowait(dr
->dr_zio
);
4323 dbuf_sync_list(list_t
*list
, int level
, dmu_tx_t
*tx
)
4325 dbuf_dirty_record_t
*dr
;
4327 while ((dr
= list_head(list
))) {
4328 if (dr
->dr_zio
!= NULL
) {
4330 * If we find an already initialized zio then we
4331 * are processing the meta-dnode, and we have finished.
4332 * The dbufs for all dnodes are put back on the list
4333 * during processing, so that we can zio_wait()
4334 * these IOs after initiating all child IOs.
4336 ASSERT3U(dr
->dr_dbuf
->db
.db_object
, ==,
4337 DMU_META_DNODE_OBJECT
);
4340 list_remove(list
, dr
);
4341 if (dr
->dr_dbuf
== NULL
) {
4342 dbuf_sync_lightweight(dr
, tx
);
4344 if (dr
->dr_dbuf
->db_blkid
!= DMU_BONUS_BLKID
&&
4345 dr
->dr_dbuf
->db_blkid
!= DMU_SPILL_BLKID
) {
4346 VERIFY3U(dr
->dr_dbuf
->db_level
, ==, level
);
4348 if (dr
->dr_dbuf
->db_level
> 0)
4349 dbuf_sync_indirect(dr
, tx
);
4351 dbuf_sync_leaf(dr
, tx
);
4358 dbuf_write_ready(zio_t
*zio
, arc_buf_t
*buf
, void *vdb
)
4360 dmu_buf_impl_t
*db
= vdb
;
4362 blkptr_t
*bp
= zio
->io_bp
;
4363 blkptr_t
*bp_orig
= &zio
->io_bp_orig
;
4364 spa_t
*spa
= zio
->io_spa
;
4369 ASSERT3P(db
->db_blkptr
, !=, NULL
);
4370 ASSERT3P(&db
->db_data_pending
->dr_bp_copy
, ==, bp
);
4374 delta
= bp_get_dsize_sync(spa
, bp
) - bp_get_dsize_sync(spa
, bp_orig
);
4375 dnode_diduse_space(dn
, delta
- zio
->io_prev_space_delta
);
4376 zio
->io_prev_space_delta
= delta
;
4378 if (bp
->blk_birth
!= 0) {
4379 ASSERT((db
->db_blkid
!= DMU_SPILL_BLKID
&&
4380 BP_GET_TYPE(bp
) == dn
->dn_type
) ||
4381 (db
->db_blkid
== DMU_SPILL_BLKID
&&
4382 BP_GET_TYPE(bp
) == dn
->dn_bonustype
) ||
4383 BP_IS_EMBEDDED(bp
));
4384 ASSERT(BP_GET_LEVEL(bp
) == db
->db_level
);
4387 mutex_enter(&db
->db_mtx
);
4390 if (db
->db_blkid
== DMU_SPILL_BLKID
) {
4391 ASSERT(dn
->dn_phys
->dn_flags
& DNODE_FLAG_SPILL_BLKPTR
);
4392 ASSERT(!(BP_IS_HOLE(bp
)) &&
4393 db
->db_blkptr
== DN_SPILL_BLKPTR(dn
->dn_phys
));
4397 if (db
->db_level
== 0) {
4398 mutex_enter(&dn
->dn_mtx
);
4399 if (db
->db_blkid
> dn
->dn_phys
->dn_maxblkid
&&
4400 db
->db_blkid
!= DMU_SPILL_BLKID
) {
4401 ASSERT0(db
->db_objset
->os_raw_receive
);
4402 dn
->dn_phys
->dn_maxblkid
= db
->db_blkid
;
4404 mutex_exit(&dn
->dn_mtx
);
4406 if (dn
->dn_type
== DMU_OT_DNODE
) {
4408 while (i
< db
->db
.db_size
) {
4410 (void *)(((char *)db
->db
.db_data
) + i
);
4412 i
+= DNODE_MIN_SIZE
;
4413 if (dnp
->dn_type
!= DMU_OT_NONE
) {
4415 i
+= dnp
->dn_extra_slots
*
4420 if (BP_IS_HOLE(bp
)) {
4427 blkptr_t
*ibp
= db
->db
.db_data
;
4428 ASSERT3U(db
->db
.db_size
, ==, 1<<dn
->dn_phys
->dn_indblkshift
);
4429 for (i
= db
->db
.db_size
>> SPA_BLKPTRSHIFT
; i
> 0; i
--, ibp
++) {
4430 if (BP_IS_HOLE(ibp
))
4432 fill
+= BP_GET_FILL(ibp
);
4437 if (!BP_IS_EMBEDDED(bp
))
4438 BP_SET_FILL(bp
, fill
);
4440 mutex_exit(&db
->db_mtx
);
4442 db_lock_type_t dblt
= dmu_buf_lock_parent(db
, RW_WRITER
, FTAG
);
4443 *db
->db_blkptr
= *bp
;
4444 dmu_buf_unlock_parent(db
, dblt
, FTAG
);
4449 * This function gets called just prior to running through the compression
4450 * stage of the zio pipeline. If we're an indirect block comprised of only
4451 * holes, then we want this indirect to be compressed away to a hole. In
4452 * order to do that we must zero out any information about the holes that
4453 * this indirect points to prior to before we try to compress it.
4456 dbuf_write_children_ready(zio_t
*zio
, arc_buf_t
*buf
, void *vdb
)
4458 dmu_buf_impl_t
*db
= vdb
;
4461 unsigned int epbs
, i
;
4463 ASSERT3U(db
->db_level
, >, 0);
4466 epbs
= dn
->dn_phys
->dn_indblkshift
- SPA_BLKPTRSHIFT
;
4467 ASSERT3U(epbs
, <, 31);
4469 /* Determine if all our children are holes */
4470 for (i
= 0, bp
= db
->db
.db_data
; i
< 1ULL << epbs
; i
++, bp
++) {
4471 if (!BP_IS_HOLE(bp
))
4476 * If all the children are holes, then zero them all out so that
4477 * we may get compressed away.
4479 if (i
== 1ULL << epbs
) {
4481 * We only found holes. Grab the rwlock to prevent
4482 * anybody from reading the blocks we're about to
4485 rw_enter(&db
->db_rwlock
, RW_WRITER
);
4486 bzero(db
->db
.db_data
, db
->db
.db_size
);
4487 rw_exit(&db
->db_rwlock
);
4493 * The SPA will call this callback several times for each zio - once
4494 * for every physical child i/o (zio->io_phys_children times). This
4495 * allows the DMU to monitor the progress of each logical i/o. For example,
4496 * there may be 2 copies of an indirect block, or many fragments of a RAID-Z
4497 * block. There may be a long delay before all copies/fragments are completed,
4498 * so this callback allows us to retire dirty space gradually, as the physical
4503 dbuf_write_physdone(zio_t
*zio
, arc_buf_t
*buf
, void *arg
)
4505 dmu_buf_impl_t
*db
= arg
;
4506 objset_t
*os
= db
->db_objset
;
4507 dsl_pool_t
*dp
= dmu_objset_pool(os
);
4508 dbuf_dirty_record_t
*dr
;
4511 dr
= db
->db_data_pending
;
4512 ASSERT3U(dr
->dr_txg
, ==, zio
->io_txg
);
4515 * The callback will be called io_phys_children times. Retire one
4516 * portion of our dirty space each time we are called. Any rounding
4517 * error will be cleaned up by dbuf_write_done().
4519 delta
= dr
->dr_accounted
/ zio
->io_phys_children
;
4520 dsl_pool_undirty_space(dp
, delta
, zio
->io_txg
);
4525 dbuf_write_done(zio_t
*zio
, arc_buf_t
*buf
, void *vdb
)
4527 dmu_buf_impl_t
*db
= vdb
;
4528 blkptr_t
*bp_orig
= &zio
->io_bp_orig
;
4529 blkptr_t
*bp
= db
->db_blkptr
;
4530 objset_t
*os
= db
->db_objset
;
4531 dmu_tx_t
*tx
= os
->os_synctx
;
4533 ASSERT0(zio
->io_error
);
4534 ASSERT(db
->db_blkptr
== bp
);
4537 * For nopwrites and rewrites we ensure that the bp matches our
4538 * original and bypass all the accounting.
4540 if (zio
->io_flags
& (ZIO_FLAG_IO_REWRITE
| ZIO_FLAG_NOPWRITE
)) {
4541 ASSERT(BP_EQUAL(bp
, bp_orig
));
4543 dsl_dataset_t
*ds
= os
->os_dsl_dataset
;
4544 (void) dsl_dataset_block_kill(ds
, bp_orig
, tx
, B_TRUE
);
4545 dsl_dataset_block_born(ds
, bp
, tx
);
4548 mutex_enter(&db
->db_mtx
);
4552 dbuf_dirty_record_t
*dr
= db
->db_data_pending
;
4553 dnode_t
*dn
= dr
->dr_dnode
;
4554 ASSERT(!list_link_active(&dr
->dr_dirty_node
));
4555 ASSERT(dr
->dr_dbuf
== db
);
4556 ASSERT(list_next(&db
->db_dirty_records
, dr
) == NULL
);
4557 list_remove(&db
->db_dirty_records
, dr
);
4560 if (db
->db_blkid
== DMU_SPILL_BLKID
) {
4561 ASSERT(dn
->dn_phys
->dn_flags
& DNODE_FLAG_SPILL_BLKPTR
);
4562 ASSERT(!(BP_IS_HOLE(db
->db_blkptr
)) &&
4563 db
->db_blkptr
== DN_SPILL_BLKPTR(dn
->dn_phys
));
4567 if (db
->db_level
== 0) {
4568 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
4569 ASSERT(dr
->dt
.dl
.dr_override_state
== DR_NOT_OVERRIDDEN
);
4570 if (db
->db_state
!= DB_NOFILL
) {
4571 if (dr
->dt
.dl
.dr_data
!= db
->db_buf
)
4572 arc_buf_destroy(dr
->dt
.dl
.dr_data
, db
);
4575 ASSERT(list_head(&dr
->dt
.di
.dr_children
) == NULL
);
4576 ASSERT3U(db
->db
.db_size
, ==, 1 << dn
->dn_phys
->dn_indblkshift
);
4577 if (!BP_IS_HOLE(db
->db_blkptr
)) {
4578 int epbs __maybe_unused
= dn
->dn_phys
->dn_indblkshift
-
4580 ASSERT3U(db
->db_blkid
, <=,
4581 dn
->dn_phys
->dn_maxblkid
>> (db
->db_level
* epbs
));
4582 ASSERT3U(BP_GET_LSIZE(db
->db_blkptr
), ==,
4585 mutex_destroy(&dr
->dt
.di
.dr_mtx
);
4586 list_destroy(&dr
->dt
.di
.dr_children
);
4589 cv_broadcast(&db
->db_changed
);
4590 ASSERT(db
->db_dirtycnt
> 0);
4591 db
->db_dirtycnt
-= 1;
4592 db
->db_data_pending
= NULL
;
4593 dbuf_rele_and_unlock(db
, (void *)(uintptr_t)tx
->tx_txg
, B_FALSE
);
4596 * If we didn't do a physical write in this ZIO and we
4597 * still ended up here, it means that the space of the
4598 * dbuf that we just released (and undirtied) above hasn't
4599 * been marked as undirtied in the pool's accounting.
4601 * Thus, we undirty that space in the pool's view of the
4602 * world here. For physical writes this type of update
4603 * happens in dbuf_write_physdone().
4605 * If we did a physical write, cleanup any rounding errors
4606 * that came up due to writing multiple copies of a block
4607 * on disk [see dbuf_write_physdone()].
4609 if (zio
->io_phys_children
== 0) {
4610 dsl_pool_undirty_space(dmu_objset_pool(os
),
4611 dr
->dr_accounted
, zio
->io_txg
);
4613 dsl_pool_undirty_space(dmu_objset_pool(os
),
4614 dr
->dr_accounted
% zio
->io_phys_children
, zio
->io_txg
);
4617 kmem_free(dr
, sizeof (dbuf_dirty_record_t
));
4621 dbuf_write_nofill_ready(zio_t
*zio
)
4623 dbuf_write_ready(zio
, NULL
, zio
->io_private
);
4627 dbuf_write_nofill_done(zio_t
*zio
)
4629 dbuf_write_done(zio
, NULL
, zio
->io_private
);
4633 dbuf_write_override_ready(zio_t
*zio
)
4635 dbuf_dirty_record_t
*dr
= zio
->io_private
;
4636 dmu_buf_impl_t
*db
= dr
->dr_dbuf
;
4638 dbuf_write_ready(zio
, NULL
, db
);
4642 dbuf_write_override_done(zio_t
*zio
)
4644 dbuf_dirty_record_t
*dr
= zio
->io_private
;
4645 dmu_buf_impl_t
*db
= dr
->dr_dbuf
;
4646 blkptr_t
*obp
= &dr
->dt
.dl
.dr_overridden_by
;
4648 mutex_enter(&db
->db_mtx
);
4649 if (!BP_EQUAL(zio
->io_bp
, obp
)) {
4650 if (!BP_IS_HOLE(obp
))
4651 dsl_free(spa_get_dsl(zio
->io_spa
), zio
->io_txg
, obp
);
4652 arc_release(dr
->dt
.dl
.dr_data
, db
);
4654 mutex_exit(&db
->db_mtx
);
4656 dbuf_write_done(zio
, NULL
, db
);
4658 if (zio
->io_abd
!= NULL
)
4659 abd_put(zio
->io_abd
);
4662 typedef struct dbuf_remap_impl_callback_arg
{
4664 uint64_t drica_blk_birth
;
4666 } dbuf_remap_impl_callback_arg_t
;
4669 dbuf_remap_impl_callback(uint64_t vdev
, uint64_t offset
, uint64_t size
,
4672 dbuf_remap_impl_callback_arg_t
*drica
= arg
;
4673 objset_t
*os
= drica
->drica_os
;
4674 spa_t
*spa
= dmu_objset_spa(os
);
4675 dmu_tx_t
*tx
= drica
->drica_tx
;
4677 ASSERT(dsl_pool_sync_context(spa_get_dsl(spa
)));
4679 if (os
== spa_meta_objset(spa
)) {
4680 spa_vdev_indirect_mark_obsolete(spa
, vdev
, offset
, size
, tx
);
4682 dsl_dataset_block_remapped(dmu_objset_ds(os
), vdev
, offset
,
4683 size
, drica
->drica_blk_birth
, tx
);
4688 dbuf_remap_impl(dnode_t
*dn
, blkptr_t
*bp
, krwlock_t
*rw
, dmu_tx_t
*tx
)
4690 blkptr_t bp_copy
= *bp
;
4691 spa_t
*spa
= dmu_objset_spa(dn
->dn_objset
);
4692 dbuf_remap_impl_callback_arg_t drica
;
4694 ASSERT(dsl_pool_sync_context(spa_get_dsl(spa
)));
4696 drica
.drica_os
= dn
->dn_objset
;
4697 drica
.drica_blk_birth
= bp
->blk_birth
;
4698 drica
.drica_tx
= tx
;
4699 if (spa_remap_blkptr(spa
, &bp_copy
, dbuf_remap_impl_callback
,
4702 * If the blkptr being remapped is tracked by a livelist,
4703 * then we need to make sure the livelist reflects the update.
4704 * First, cancel out the old blkptr by appending a 'FREE'
4705 * entry. Next, add an 'ALLOC' to track the new version. This
4706 * way we avoid trying to free an inaccurate blkptr at delete.
4707 * Note that embedded blkptrs are not tracked in livelists.
4709 if (dn
->dn_objset
!= spa_meta_objset(spa
)) {
4710 dsl_dataset_t
*ds
= dmu_objset_ds(dn
->dn_objset
);
4711 if (dsl_deadlist_is_open(&ds
->ds_dir
->dd_livelist
) &&
4712 bp
->blk_birth
> ds
->ds_dir
->dd_origin_txg
) {
4713 ASSERT(!BP_IS_EMBEDDED(bp
));
4714 ASSERT(dsl_dir_is_clone(ds
->ds_dir
));
4715 ASSERT(spa_feature_is_enabled(spa
,
4716 SPA_FEATURE_LIVELIST
));
4717 bplist_append(&ds
->ds_dir
->dd_pending_frees
,
4719 bplist_append(&ds
->ds_dir
->dd_pending_allocs
,
4725 * The db_rwlock prevents dbuf_read_impl() from
4726 * dereferencing the BP while we are changing it. To
4727 * avoid lock contention, only grab it when we are actually
4731 rw_enter(rw
, RW_WRITER
);
4739 * Remap any existing BP's to concrete vdevs, if possible.
4742 dbuf_remap(dnode_t
*dn
, dmu_buf_impl_t
*db
, dmu_tx_t
*tx
)
4744 spa_t
*spa
= dmu_objset_spa(db
->db_objset
);
4745 ASSERT(dsl_pool_sync_context(spa_get_dsl(spa
)));
4747 if (!spa_feature_is_active(spa
, SPA_FEATURE_DEVICE_REMOVAL
))
4750 if (db
->db_level
> 0) {
4751 blkptr_t
*bp
= db
->db
.db_data
;
4752 for (int i
= 0; i
< db
->db
.db_size
>> SPA_BLKPTRSHIFT
; i
++) {
4753 dbuf_remap_impl(dn
, &bp
[i
], &db
->db_rwlock
, tx
);
4755 } else if (db
->db
.db_object
== DMU_META_DNODE_OBJECT
) {
4756 dnode_phys_t
*dnp
= db
->db
.db_data
;
4757 ASSERT3U(db
->db_dnode_handle
->dnh_dnode
->dn_type
, ==,
4759 for (int i
= 0; i
< db
->db
.db_size
>> DNODE_SHIFT
;
4760 i
+= dnp
[i
].dn_extra_slots
+ 1) {
4761 for (int j
= 0; j
< dnp
[i
].dn_nblkptr
; j
++) {
4762 krwlock_t
*lock
= (dn
->dn_dbuf
== NULL
? NULL
:
4763 &dn
->dn_dbuf
->db_rwlock
);
4764 dbuf_remap_impl(dn
, &dnp
[i
].dn_blkptr
[j
], lock
,
4772 /* Issue I/O to commit a dirty buffer to disk. */
4774 dbuf_write(dbuf_dirty_record_t
*dr
, arc_buf_t
*data
, dmu_tx_t
*tx
)
4776 dmu_buf_impl_t
*db
= dr
->dr_dbuf
;
4777 dnode_t
*dn
= dr
->dr_dnode
;
4779 dmu_buf_impl_t
*parent
= db
->db_parent
;
4780 uint64_t txg
= tx
->tx_txg
;
4781 zbookmark_phys_t zb
;
4783 zio_t
*pio
; /* parent I/O */
4786 ASSERT(dmu_tx_is_syncing(tx
));
4790 if (db
->db_state
!= DB_NOFILL
) {
4791 if (db
->db_level
> 0 || dn
->dn_type
== DMU_OT_DNODE
) {
4793 * Private object buffers are released here rather
4794 * than in dbuf_dirty() since they are only modified
4795 * in the syncing context and we don't want the
4796 * overhead of making multiple copies of the data.
4798 if (BP_IS_HOLE(db
->db_blkptr
)) {
4801 dbuf_release_bp(db
);
4803 dbuf_remap(dn
, db
, tx
);
4807 if (parent
!= dn
->dn_dbuf
) {
4808 /* Our parent is an indirect block. */
4809 /* We have a dirty parent that has been scheduled for write. */
4810 ASSERT(parent
&& parent
->db_data_pending
);
4811 /* Our parent's buffer is one level closer to the dnode. */
4812 ASSERT(db
->db_level
== parent
->db_level
-1);
4814 * We're about to modify our parent's db_data by modifying
4815 * our block pointer, so the parent must be released.
4817 ASSERT(arc_released(parent
->db_buf
));
4818 pio
= parent
->db_data_pending
->dr_zio
;
4820 /* Our parent is the dnode itself. */
4821 ASSERT((db
->db_level
== dn
->dn_phys
->dn_nlevels
-1 &&
4822 db
->db_blkid
!= DMU_SPILL_BLKID
) ||
4823 (db
->db_blkid
== DMU_SPILL_BLKID
&& db
->db_level
== 0));
4824 if (db
->db_blkid
!= DMU_SPILL_BLKID
)
4825 ASSERT3P(db
->db_blkptr
, ==,
4826 &dn
->dn_phys
->dn_blkptr
[db
->db_blkid
]);
4830 ASSERT(db
->db_level
== 0 || data
== db
->db_buf
);
4831 ASSERT3U(db
->db_blkptr
->blk_birth
, <=, txg
);
4834 SET_BOOKMARK(&zb
, os
->os_dsl_dataset
?
4835 os
->os_dsl_dataset
->ds_object
: DMU_META_OBJSET
,
4836 db
->db
.db_object
, db
->db_level
, db
->db_blkid
);
4838 if (db
->db_blkid
== DMU_SPILL_BLKID
)
4840 wp_flag
|= (db
->db_state
== DB_NOFILL
) ? WP_NOFILL
: 0;
4842 dmu_write_policy(os
, dn
, db
->db_level
, wp_flag
, &zp
);
4845 * We copy the blkptr now (rather than when we instantiate the dirty
4846 * record), because its value can change between open context and
4847 * syncing context. We do not need to hold dn_struct_rwlock to read
4848 * db_blkptr because we are in syncing context.
4850 dr
->dr_bp_copy
= *db
->db_blkptr
;
4852 if (db
->db_level
== 0 &&
4853 dr
->dt
.dl
.dr_override_state
== DR_OVERRIDDEN
) {
4855 * The BP for this block has been provided by open context
4856 * (by dmu_sync() or dmu_buf_write_embedded()).
4858 abd_t
*contents
= (data
!= NULL
) ?
4859 abd_get_from_buf(data
->b_data
, arc_buf_size(data
)) : NULL
;
4861 dr
->dr_zio
= zio_write(pio
, os
->os_spa
, txg
, &dr
->dr_bp_copy
,
4862 contents
, db
->db
.db_size
, db
->db
.db_size
, &zp
,
4863 dbuf_write_override_ready
, NULL
, NULL
,
4864 dbuf_write_override_done
,
4865 dr
, ZIO_PRIORITY_ASYNC_WRITE
, ZIO_FLAG_MUSTSUCCEED
, &zb
);
4866 mutex_enter(&db
->db_mtx
);
4867 dr
->dt
.dl
.dr_override_state
= DR_NOT_OVERRIDDEN
;
4868 zio_write_override(dr
->dr_zio
, &dr
->dt
.dl
.dr_overridden_by
,
4869 dr
->dt
.dl
.dr_copies
, dr
->dt
.dl
.dr_nopwrite
);
4870 mutex_exit(&db
->db_mtx
);
4871 } else if (db
->db_state
== DB_NOFILL
) {
4872 ASSERT(zp
.zp_checksum
== ZIO_CHECKSUM_OFF
||
4873 zp
.zp_checksum
== ZIO_CHECKSUM_NOPARITY
);
4874 dr
->dr_zio
= zio_write(pio
, os
->os_spa
, txg
,
4875 &dr
->dr_bp_copy
, NULL
, db
->db
.db_size
, db
->db
.db_size
, &zp
,
4876 dbuf_write_nofill_ready
, NULL
, NULL
,
4877 dbuf_write_nofill_done
, db
,
4878 ZIO_PRIORITY_ASYNC_WRITE
,
4879 ZIO_FLAG_MUSTSUCCEED
| ZIO_FLAG_NODATA
, &zb
);
4881 ASSERT(arc_released(data
));
4884 * For indirect blocks, we want to setup the children
4885 * ready callback so that we can properly handle an indirect
4886 * block that only contains holes.
4888 arc_write_done_func_t
*children_ready_cb
= NULL
;
4889 if (db
->db_level
!= 0)
4890 children_ready_cb
= dbuf_write_children_ready
;
4892 dr
->dr_zio
= arc_write(pio
, os
->os_spa
, txg
,
4893 &dr
->dr_bp_copy
, data
, DBUF_IS_L2CACHEABLE(db
),
4894 &zp
, dbuf_write_ready
,
4895 children_ready_cb
, dbuf_write_physdone
,
4896 dbuf_write_done
, db
, ZIO_PRIORITY_ASYNC_WRITE
,
4897 ZIO_FLAG_MUSTSUCCEED
, &zb
);
4901 EXPORT_SYMBOL(dbuf_find
);
4902 EXPORT_SYMBOL(dbuf_is_metadata
);
4903 EXPORT_SYMBOL(dbuf_destroy
);
4904 EXPORT_SYMBOL(dbuf_loan_arcbuf
);
4905 EXPORT_SYMBOL(dbuf_whichblock
);
4906 EXPORT_SYMBOL(dbuf_read
);
4907 EXPORT_SYMBOL(dbuf_unoverride
);
4908 EXPORT_SYMBOL(dbuf_free_range
);
4909 EXPORT_SYMBOL(dbuf_new_size
);
4910 EXPORT_SYMBOL(dbuf_release_bp
);
4911 EXPORT_SYMBOL(dbuf_dirty
);
4912 EXPORT_SYMBOL(dmu_buf_set_crypt_params
);
4913 EXPORT_SYMBOL(dmu_buf_will_dirty
);
4914 EXPORT_SYMBOL(dmu_buf_is_dirty
);
4915 EXPORT_SYMBOL(dmu_buf_will_not_fill
);
4916 EXPORT_SYMBOL(dmu_buf_will_fill
);
4917 EXPORT_SYMBOL(dmu_buf_fill_done
);
4918 EXPORT_SYMBOL(dmu_buf_rele
);
4919 EXPORT_SYMBOL(dbuf_assign_arcbuf
);
4920 EXPORT_SYMBOL(dbuf_prefetch
);
4921 EXPORT_SYMBOL(dbuf_hold_impl
);
4922 EXPORT_SYMBOL(dbuf_hold
);
4923 EXPORT_SYMBOL(dbuf_hold_level
);
4924 EXPORT_SYMBOL(dbuf_create_bonus
);
4925 EXPORT_SYMBOL(dbuf_spill_set_blksz
);
4926 EXPORT_SYMBOL(dbuf_rm_spill
);
4927 EXPORT_SYMBOL(dbuf_add_ref
);
4928 EXPORT_SYMBOL(dbuf_rele
);
4929 EXPORT_SYMBOL(dbuf_rele_and_unlock
);
4930 EXPORT_SYMBOL(dbuf_refcount
);
4931 EXPORT_SYMBOL(dbuf_sync_list
);
4932 EXPORT_SYMBOL(dmu_buf_set_user
);
4933 EXPORT_SYMBOL(dmu_buf_set_user_ie
);
4934 EXPORT_SYMBOL(dmu_buf_get_user
);
4935 EXPORT_SYMBOL(dmu_buf_get_blkptr
);
4938 ZFS_MODULE_PARAM(zfs_dbuf_cache
, dbuf_cache_
, max_bytes
, ULONG
, ZMOD_RW
,
4939 "Maximum size in bytes of the dbuf cache.");
4941 ZFS_MODULE_PARAM(zfs_dbuf_cache
, dbuf_cache_
, hiwater_pct
, UINT
, ZMOD_RW
,
4942 "Percentage over dbuf_cache_max_bytes when dbufs must be evicted "
4945 ZFS_MODULE_PARAM(zfs_dbuf_cache
, dbuf_cache_
, lowater_pct
, UINT
, ZMOD_RW
,
4946 "Percentage below dbuf_cache_max_bytes when the evict thread stops "
4949 ZFS_MODULE_PARAM(zfs_dbuf
, dbuf_
, metadata_cache_max_bytes
, ULONG
, ZMOD_RW
,
4950 "Maximum size in bytes of the dbuf metadata cache.");
4952 ZFS_MODULE_PARAM(zfs_dbuf
, dbuf_
, cache_shift
, INT
, ZMOD_RW
,
4953 "Set the size of the dbuf cache to a log2 fraction of arc size.");
4955 ZFS_MODULE_PARAM(zfs_dbuf
, dbuf_
, metadata_cache_shift
, INT
, ZMOD_RW
,
4956 "Set the size of the dbuf metadata cache to a log2 fraction of arc "