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, 2017 by Delphix. All rights reserved.
25 * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
26 * Copyright (c) 2013, Joyent, Inc. All rights reserved.
27 * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
28 * Copyright (c) 2014 Integros [integros.com]
31 #include <sys/zfs_context.h>
33 #include <sys/dmu_send.h>
34 #include <sys/dmu_impl.h>
36 #include <sys/dmu_objset.h>
37 #include <sys/dsl_dataset.h>
38 #include <sys/dsl_dir.h>
39 #include <sys/dmu_tx.h>
42 #include <sys/dmu_zfetch.h>
44 #include <sys/sa_impl.h>
45 #include <sys/zfeature.h>
46 #include <sys/blkptr.h>
47 #include <sys/range_tree.h>
48 #include <sys/callb.h>
52 uint_t zfs_dbuf_evict_key
;
54 static boolean_t
dbuf_undirty(dmu_buf_impl_t
*db
, dmu_tx_t
*tx
);
55 static void dbuf_write(dbuf_dirty_record_t
*dr
, arc_buf_t
*data
, dmu_tx_t
*tx
);
58 extern inline void dmu_buf_init_user(dmu_buf_user_t
*dbu
,
59 dmu_buf_evict_func_t
*evict_func_sync
,
60 dmu_buf_evict_func_t
*evict_func_async
,
61 dmu_buf_t
**clear_on_evict_dbufp
);
65 * Global data structures and functions for the dbuf cache.
67 static kmem_cache_t
*dbuf_kmem_cache
;
68 static taskq_t
*dbu_evict_taskq
;
70 static kthread_t
*dbuf_cache_evict_thread
;
71 static kmutex_t dbuf_evict_lock
;
72 static kcondvar_t dbuf_evict_cv
;
73 static boolean_t dbuf_evict_thread_exit
;
76 * LRU cache of dbufs. The dbuf cache maintains a list of dbufs that
77 * are not currently held but have been recently released. These dbufs
78 * are not eligible for arc eviction until they are aged out of the cache.
79 * Dbufs are added to the dbuf cache once the last hold is released. If a
80 * dbuf is later accessed and still exists in the dbuf cache, then it will
81 * be removed from the cache and later re-added to the head of the cache.
82 * Dbufs that are aged out of the cache will be immediately destroyed and
83 * become eligible for arc eviction.
85 static multilist_t
*dbuf_cache
;
86 static refcount_t dbuf_cache_size
;
87 uint64_t dbuf_cache_max_bytes
= 100 * 1024 * 1024;
89 /* Cap the size of the dbuf cache to log2 fraction of arc size. */
90 int dbuf_cache_max_shift
= 5;
93 * The dbuf cache uses a three-stage eviction policy:
94 * - A low water marker designates when the dbuf eviction thread
95 * should stop evicting from the dbuf cache.
96 * - When we reach the maximum size (aka mid water mark), we
97 * signal the eviction thread to run.
98 * - The high water mark indicates when the eviction thread
99 * is unable to keep up with the incoming load and eviction must
100 * happen in the context of the calling thread.
104 * low water mid water hi water
105 * +----------------------------------------+----------+----------+
110 * +----------------------------------------+----------+----------+
112 * evicting eviction directly
115 * The high and low water marks indicate the operating range for the eviction
116 * thread. The low water mark is, by default, 90% of the total size of the
117 * cache and the high water mark is at 110% (both of these percentages can be
118 * changed by setting dbuf_cache_lowater_pct and dbuf_cache_hiwater_pct,
119 * respectively). The eviction thread will try to ensure that the cache remains
120 * within this range by waking up every second and checking if the cache is
121 * above the low water mark. The thread can also be woken up by callers adding
122 * elements into the cache if the cache is larger than the mid water (i.e max
123 * cache size). Once the eviction thread is woken up and eviction is required,
124 * it will continue evicting buffers until it's able to reduce the cache size
125 * to the low water mark. If the cache size continues to grow and hits the high
126 * water mark, then callers adding elments to the cache will begin to evict
127 * directly from the cache until the cache is no longer above the high water
132 * The percentage above and below the maximum cache size.
134 uint_t dbuf_cache_hiwater_pct
= 10;
135 uint_t dbuf_cache_lowater_pct
= 10;
139 dbuf_cons(void *vdb
, void *unused
, int kmflag
)
141 dmu_buf_impl_t
*db
= vdb
;
142 bzero(db
, sizeof (dmu_buf_impl_t
));
144 mutex_init(&db
->db_mtx
, NULL
, MUTEX_DEFAULT
, NULL
);
145 cv_init(&db
->db_changed
, NULL
, CV_DEFAULT
, NULL
);
146 multilist_link_init(&db
->db_cache_link
);
147 refcount_create(&db
->db_holds
);
154 dbuf_dest(void *vdb
, void *unused
)
156 dmu_buf_impl_t
*db
= vdb
;
157 mutex_destroy(&db
->db_mtx
);
158 cv_destroy(&db
->db_changed
);
159 ASSERT(!multilist_link_active(&db
->db_cache_link
));
160 refcount_destroy(&db
->db_holds
);
164 * dbuf hash table routines
166 static dbuf_hash_table_t dbuf_hash_table
;
168 static uint64_t dbuf_hash_count
;
171 dbuf_hash(void *os
, uint64_t obj
, uint8_t lvl
, uint64_t blkid
)
173 uintptr_t osv
= (uintptr_t)os
;
174 uint64_t crc
= -1ULL;
176 ASSERT(zfs_crc64_table
[128] == ZFS_CRC64_POLY
);
177 crc
= (crc
>> 8) ^ zfs_crc64_table
[(crc
^ (lvl
)) & 0xFF];
178 crc
= (crc
>> 8) ^ zfs_crc64_table
[(crc
^ (osv
>> 6)) & 0xFF];
179 crc
= (crc
>> 8) ^ zfs_crc64_table
[(crc
^ (obj
>> 0)) & 0xFF];
180 crc
= (crc
>> 8) ^ zfs_crc64_table
[(crc
^ (obj
>> 8)) & 0xFF];
181 crc
= (crc
>> 8) ^ zfs_crc64_table
[(crc
^ (blkid
>> 0)) & 0xFF];
182 crc
= (crc
>> 8) ^ zfs_crc64_table
[(crc
^ (blkid
>> 8)) & 0xFF];
184 crc
^= (osv
>>14) ^ (obj
>>16) ^ (blkid
>>16);
189 #define DBUF_EQUAL(dbuf, os, obj, level, blkid) \
190 ((dbuf)->db.db_object == (obj) && \
191 (dbuf)->db_objset == (os) && \
192 (dbuf)->db_level == (level) && \
193 (dbuf)->db_blkid == (blkid))
196 dbuf_find(objset_t
*os
, uint64_t obj
, uint8_t level
, uint64_t blkid
)
198 dbuf_hash_table_t
*h
= &dbuf_hash_table
;
199 uint64_t hv
= dbuf_hash(os
, obj
, level
, blkid
);
200 uint64_t idx
= hv
& h
->hash_table_mask
;
203 mutex_enter(DBUF_HASH_MUTEX(h
, idx
));
204 for (db
= h
->hash_table
[idx
]; db
!= NULL
; db
= db
->db_hash_next
) {
205 if (DBUF_EQUAL(db
, os
, obj
, level
, blkid
)) {
206 mutex_enter(&db
->db_mtx
);
207 if (db
->db_state
!= DB_EVICTING
) {
208 mutex_exit(DBUF_HASH_MUTEX(h
, idx
));
211 mutex_exit(&db
->db_mtx
);
214 mutex_exit(DBUF_HASH_MUTEX(h
, idx
));
218 static dmu_buf_impl_t
*
219 dbuf_find_bonus(objset_t
*os
, uint64_t object
)
222 dmu_buf_impl_t
*db
= NULL
;
224 if (dnode_hold(os
, object
, FTAG
, &dn
) == 0) {
225 rw_enter(&dn
->dn_struct_rwlock
, RW_READER
);
226 if (dn
->dn_bonus
!= NULL
) {
228 mutex_enter(&db
->db_mtx
);
230 rw_exit(&dn
->dn_struct_rwlock
);
231 dnode_rele(dn
, FTAG
);
237 * Insert an entry into the hash table. If there is already an element
238 * equal to elem in the hash table, then the already existing element
239 * will be returned and the new element will not be inserted.
240 * Otherwise returns NULL.
242 static dmu_buf_impl_t
*
243 dbuf_hash_insert(dmu_buf_impl_t
*db
)
245 dbuf_hash_table_t
*h
= &dbuf_hash_table
;
246 objset_t
*os
= db
->db_objset
;
247 uint64_t obj
= db
->db
.db_object
;
248 int level
= db
->db_level
;
249 uint64_t blkid
= db
->db_blkid
;
250 uint64_t hv
= dbuf_hash(os
, obj
, level
, blkid
);
251 uint64_t idx
= hv
& h
->hash_table_mask
;
254 mutex_enter(DBUF_HASH_MUTEX(h
, idx
));
255 for (dbf
= h
->hash_table
[idx
]; dbf
!= NULL
; dbf
= dbf
->db_hash_next
) {
256 if (DBUF_EQUAL(dbf
, os
, obj
, level
, blkid
)) {
257 mutex_enter(&dbf
->db_mtx
);
258 if (dbf
->db_state
!= DB_EVICTING
) {
259 mutex_exit(DBUF_HASH_MUTEX(h
, idx
));
262 mutex_exit(&dbf
->db_mtx
);
266 mutex_enter(&db
->db_mtx
);
267 db
->db_hash_next
= h
->hash_table
[idx
];
268 h
->hash_table
[idx
] = db
;
269 mutex_exit(DBUF_HASH_MUTEX(h
, idx
));
270 atomic_inc_64(&dbuf_hash_count
);
276 * Remove an entry from the hash table. It must be in the EVICTING state.
279 dbuf_hash_remove(dmu_buf_impl_t
*db
)
281 dbuf_hash_table_t
*h
= &dbuf_hash_table
;
282 uint64_t hv
= dbuf_hash(db
->db_objset
, db
->db
.db_object
,
283 db
->db_level
, db
->db_blkid
);
284 uint64_t idx
= hv
& h
->hash_table_mask
;
285 dmu_buf_impl_t
*dbf
, **dbp
;
288 * We musn't hold db_mtx to maintain lock ordering:
289 * DBUF_HASH_MUTEX > db_mtx.
291 ASSERT(refcount_is_zero(&db
->db_holds
));
292 ASSERT(db
->db_state
== DB_EVICTING
);
293 ASSERT(!MUTEX_HELD(&db
->db_mtx
));
295 mutex_enter(DBUF_HASH_MUTEX(h
, idx
));
296 dbp
= &h
->hash_table
[idx
];
297 while ((dbf
= *dbp
) != db
) {
298 dbp
= &dbf
->db_hash_next
;
301 *dbp
= db
->db_hash_next
;
302 db
->db_hash_next
= NULL
;
303 mutex_exit(DBUF_HASH_MUTEX(h
, idx
));
304 atomic_dec_64(&dbuf_hash_count
);
310 } dbvu_verify_type_t
;
313 dbuf_verify_user(dmu_buf_impl_t
*db
, dbvu_verify_type_t verify_type
)
318 if (db
->db_user
== NULL
)
321 /* Only data blocks support the attachment of user data. */
322 ASSERT(db
->db_level
== 0);
324 /* Clients must resolve a dbuf before attaching user data. */
325 ASSERT(db
->db
.db_data
!= NULL
);
326 ASSERT3U(db
->db_state
, ==, DB_CACHED
);
328 holds
= refcount_count(&db
->db_holds
);
329 if (verify_type
== DBVU_EVICTING
) {
331 * Immediate eviction occurs when holds == dirtycnt.
332 * For normal eviction buffers, holds is zero on
333 * eviction, except when dbuf_fix_old_data() calls
334 * dbuf_clear_data(). However, the hold count can grow
335 * during eviction even though db_mtx is held (see
336 * dmu_bonus_hold() for an example), so we can only
337 * test the generic invariant that holds >= dirtycnt.
339 ASSERT3U(holds
, >=, db
->db_dirtycnt
);
341 if (db
->db_user_immediate_evict
== TRUE
)
342 ASSERT3U(holds
, >=, db
->db_dirtycnt
);
344 ASSERT3U(holds
, >, 0);
350 dbuf_evict_user(dmu_buf_impl_t
*db
)
352 dmu_buf_user_t
*dbu
= db
->db_user
;
354 ASSERT(MUTEX_HELD(&db
->db_mtx
));
359 dbuf_verify_user(db
, DBVU_EVICTING
);
363 if (dbu
->dbu_clear_on_evict_dbufp
!= NULL
)
364 *dbu
->dbu_clear_on_evict_dbufp
= NULL
;
368 * There are two eviction callbacks - one that we call synchronously
369 * and one that we invoke via a taskq. The async one is useful for
370 * avoiding lock order reversals and limiting stack depth.
372 * Note that if we have a sync callback but no async callback,
373 * it's likely that the sync callback will free the structure
374 * containing the dbu. In that case we need to take care to not
375 * dereference dbu after calling the sync evict func.
377 boolean_t has_async
= (dbu
->dbu_evict_func_async
!= NULL
);
379 if (dbu
->dbu_evict_func_sync
!= NULL
)
380 dbu
->dbu_evict_func_sync(dbu
);
383 taskq_dispatch_ent(dbu_evict_taskq
, dbu
->dbu_evict_func_async
,
384 dbu
, 0, &dbu
->dbu_tqent
);
389 dbuf_is_metadata(dmu_buf_impl_t
*db
)
391 if (db
->db_level
> 0) {
394 boolean_t is_metadata
;
397 is_metadata
= DMU_OT_IS_METADATA(DB_DNODE(db
)->dn_type
);
400 return (is_metadata
);
405 * This function *must* return indices evenly distributed between all
406 * sublists of the multilist. This is needed due to how the dbuf eviction
407 * code is laid out; dbuf_evict_thread() assumes dbufs are evenly
408 * distributed between all sublists and uses this assumption when
409 * deciding which sublist to evict from and how much to evict from it.
412 dbuf_cache_multilist_index_func(multilist_t
*ml
, void *obj
)
414 dmu_buf_impl_t
*db
= obj
;
417 * The assumption here, is the hash value for a given
418 * dmu_buf_impl_t will remain constant throughout it's lifetime
419 * (i.e. it's objset, object, level and blkid fields don't change).
420 * Thus, we don't need to store the dbuf's sublist index
421 * on insertion, as this index can be recalculated on removal.
423 * Also, the low order bits of the hash value are thought to be
424 * distributed evenly. Otherwise, in the case that the multilist
425 * has a power of two number of sublists, each sublists' usage
426 * would not be evenly distributed.
428 return (dbuf_hash(db
->db_objset
, db
->db
.db_object
,
429 db
->db_level
, db
->db_blkid
) %
430 multilist_get_num_sublists(ml
));
433 static inline boolean_t
434 dbuf_cache_above_hiwater(void)
436 uint64_t dbuf_cache_hiwater_bytes
=
437 (dbuf_cache_max_bytes
* dbuf_cache_hiwater_pct
) / 100;
439 return (refcount_count(&dbuf_cache_size
) >
440 dbuf_cache_max_bytes
+ dbuf_cache_hiwater_bytes
);
443 static inline boolean_t
444 dbuf_cache_above_lowater(void)
446 uint64_t dbuf_cache_lowater_bytes
=
447 (dbuf_cache_max_bytes
* dbuf_cache_lowater_pct
) / 100;
449 return (refcount_count(&dbuf_cache_size
) >
450 dbuf_cache_max_bytes
- dbuf_cache_lowater_bytes
);
454 * Evict the oldest eligible dbuf from the dbuf cache.
459 int idx
= multilist_get_random_index(dbuf_cache
);
460 multilist_sublist_t
*mls
= multilist_sublist_lock(dbuf_cache
, idx
);
462 ASSERT(!MUTEX_HELD(&dbuf_evict_lock
));
465 * Set the thread's tsd to indicate that it's processing evictions.
466 * Once a thread stops evicting from the dbuf cache it will
467 * reset its tsd to NULL.
469 ASSERT3P(tsd_get(zfs_dbuf_evict_key
), ==, NULL
);
470 (void) tsd_set(zfs_dbuf_evict_key
, (void *)B_TRUE
);
472 dmu_buf_impl_t
*db
= multilist_sublist_tail(mls
);
473 while (db
!= NULL
&& mutex_tryenter(&db
->db_mtx
) == 0) {
474 db
= multilist_sublist_prev(mls
, db
);
477 DTRACE_PROBE2(dbuf__evict__one
, dmu_buf_impl_t
*, db
,
478 multilist_sublist_t
*, mls
);
481 multilist_sublist_remove(mls
, db
);
482 multilist_sublist_unlock(mls
);
483 (void) refcount_remove_many(&dbuf_cache_size
,
487 multilist_sublist_unlock(mls
);
489 (void) tsd_set(zfs_dbuf_evict_key
, NULL
);
493 * The dbuf evict thread is responsible for aging out dbufs from the
494 * cache. Once the cache has reached it's maximum size, dbufs are removed
495 * and destroyed. The eviction thread will continue running until the size
496 * of the dbuf cache is at or below the maximum size. Once the dbuf is aged
497 * out of the cache it is destroyed and becomes eligible for arc eviction.
501 dbuf_evict_thread(void *unused
)
505 CALLB_CPR_INIT(&cpr
, &dbuf_evict_lock
, callb_generic_cpr
, FTAG
);
507 mutex_enter(&dbuf_evict_lock
);
508 while (!dbuf_evict_thread_exit
) {
509 while (!dbuf_cache_above_lowater() && !dbuf_evict_thread_exit
) {
510 CALLB_CPR_SAFE_BEGIN(&cpr
);
511 (void) cv_timedwait_hires(&dbuf_evict_cv
,
512 &dbuf_evict_lock
, SEC2NSEC(1), MSEC2NSEC(1), 0);
513 CALLB_CPR_SAFE_END(&cpr
, &dbuf_evict_lock
);
515 mutex_exit(&dbuf_evict_lock
);
518 * Keep evicting as long as we're above the low water mark
519 * for the cache. We do this without holding the locks to
520 * minimize lock contention.
522 while (dbuf_cache_above_lowater() && !dbuf_evict_thread_exit
) {
526 mutex_enter(&dbuf_evict_lock
);
529 dbuf_evict_thread_exit
= B_FALSE
;
530 cv_broadcast(&dbuf_evict_cv
);
531 CALLB_CPR_EXIT(&cpr
); /* drops dbuf_evict_lock */
536 * Wake up the dbuf eviction thread if the dbuf cache is at its max size.
537 * If the dbuf cache is at its high water mark, then evict a dbuf from the
538 * dbuf cache using the callers context.
541 dbuf_evict_notify(void)
545 * We use thread specific data to track when a thread has
546 * started processing evictions. This allows us to avoid deeply
547 * nested stacks that would have a call flow similar to this:
549 * dbuf_rele()-->dbuf_rele_and_unlock()-->dbuf_evict_notify()
552 * +-----dbuf_destroy()<--dbuf_evict_one()<--------+
554 * The dbuf_eviction_thread will always have its tsd set until
555 * that thread exits. All other threads will only set their tsd
556 * if they are participating in the eviction process. This only
557 * happens if the eviction thread is unable to process evictions
558 * fast enough. To keep the dbuf cache size in check, other threads
559 * can evict from the dbuf cache directly. Those threads will set
560 * their tsd values so that we ensure that they only evict one dbuf
561 * from the dbuf cache.
563 if (tsd_get(zfs_dbuf_evict_key
) != NULL
)
567 * We check if we should evict without holding the dbuf_evict_lock,
568 * because it's OK to occasionally make the wrong decision here,
569 * and grabbing the lock results in massive lock contention.
571 if (refcount_count(&dbuf_cache_size
) > dbuf_cache_max_bytes
) {
572 if (dbuf_cache_above_hiwater())
574 cv_signal(&dbuf_evict_cv
);
581 uint64_t hsize
= 1ULL << 16;
582 dbuf_hash_table_t
*h
= &dbuf_hash_table
;
586 * The hash table is big enough to fill all of physical memory
587 * with an average 4K block size. The table will take up
588 * totalmem*sizeof(void*)/4K (i.e. 2MB/GB with 8-byte pointers).
590 while (hsize
* 4096 < physmem
* PAGESIZE
)
594 h
->hash_table_mask
= hsize
- 1;
595 h
->hash_table
= kmem_zalloc(hsize
* sizeof (void *), KM_NOSLEEP
);
596 if (h
->hash_table
== NULL
) {
597 /* XXX - we should really return an error instead of assert */
598 ASSERT(hsize
> (1ULL << 10));
603 dbuf_kmem_cache
= kmem_cache_create("dmu_buf_impl_t",
604 sizeof (dmu_buf_impl_t
),
605 0, dbuf_cons
, dbuf_dest
, NULL
, NULL
, NULL
, 0);
607 for (i
= 0; i
< DBUF_MUTEXES
; i
++)
608 mutex_init(&h
->hash_mutexes
[i
], NULL
, MUTEX_DEFAULT
, NULL
);
611 * Setup the parameters for the dbuf cache. We cap the size of the
612 * dbuf cache to 1/32nd (default) of the size of the ARC.
614 dbuf_cache_max_bytes
= MIN(dbuf_cache_max_bytes
,
615 arc_max_bytes() >> dbuf_cache_max_shift
);
618 * All entries are queued via taskq_dispatch_ent(), so min/maxalloc
619 * configuration is not required.
621 dbu_evict_taskq
= taskq_create("dbu_evict", 1, minclsyspri
, 0, 0, 0);
623 dbuf_cache
= multilist_create(sizeof (dmu_buf_impl_t
),
624 offsetof(dmu_buf_impl_t
, db_cache_link
),
625 dbuf_cache_multilist_index_func
);
626 refcount_create(&dbuf_cache_size
);
628 tsd_create(&zfs_dbuf_evict_key
, NULL
);
629 dbuf_evict_thread_exit
= B_FALSE
;
630 mutex_init(&dbuf_evict_lock
, NULL
, MUTEX_DEFAULT
, NULL
);
631 cv_init(&dbuf_evict_cv
, NULL
, CV_DEFAULT
, NULL
);
632 dbuf_cache_evict_thread
= thread_create(NULL
, 0, dbuf_evict_thread
,
633 NULL
, 0, &p0
, TS_RUN
, minclsyspri
);
639 dbuf_hash_table_t
*h
= &dbuf_hash_table
;
642 for (i
= 0; i
< DBUF_MUTEXES
; i
++)
643 mutex_destroy(&h
->hash_mutexes
[i
]);
644 kmem_free(h
->hash_table
, (h
->hash_table_mask
+ 1) * sizeof (void *));
645 kmem_cache_destroy(dbuf_kmem_cache
);
646 taskq_destroy(dbu_evict_taskq
);
648 mutex_enter(&dbuf_evict_lock
);
649 dbuf_evict_thread_exit
= B_TRUE
;
650 while (dbuf_evict_thread_exit
) {
651 cv_signal(&dbuf_evict_cv
);
652 cv_wait(&dbuf_evict_cv
, &dbuf_evict_lock
);
654 mutex_exit(&dbuf_evict_lock
);
655 tsd_destroy(&zfs_dbuf_evict_key
);
657 mutex_destroy(&dbuf_evict_lock
);
658 cv_destroy(&dbuf_evict_cv
);
660 refcount_destroy(&dbuf_cache_size
);
661 multilist_destroy(dbuf_cache
);
670 dbuf_verify(dmu_buf_impl_t
*db
)
673 dbuf_dirty_record_t
*dr
;
675 ASSERT(MUTEX_HELD(&db
->db_mtx
));
677 if (!(zfs_flags
& ZFS_DEBUG_DBUF_VERIFY
))
680 ASSERT(db
->db_objset
!= NULL
);
684 ASSERT(db
->db_parent
== NULL
);
685 ASSERT(db
->db_blkptr
== NULL
);
687 ASSERT3U(db
->db
.db_object
, ==, dn
->dn_object
);
688 ASSERT3P(db
->db_objset
, ==, dn
->dn_objset
);
689 ASSERT3U(db
->db_level
, <, dn
->dn_nlevels
);
690 ASSERT(db
->db_blkid
== DMU_BONUS_BLKID
||
691 db
->db_blkid
== DMU_SPILL_BLKID
||
692 !avl_is_empty(&dn
->dn_dbufs
));
694 if (db
->db_blkid
== DMU_BONUS_BLKID
) {
696 ASSERT3U(db
->db
.db_size
, >=, dn
->dn_bonuslen
);
697 ASSERT3U(db
->db
.db_offset
, ==, DMU_BONUS_BLKID
);
698 } else if (db
->db_blkid
== DMU_SPILL_BLKID
) {
700 ASSERT3U(db
->db
.db_size
, >=, dn
->dn_bonuslen
);
701 ASSERT0(db
->db
.db_offset
);
703 ASSERT3U(db
->db
.db_offset
, ==, db
->db_blkid
* db
->db
.db_size
);
706 for (dr
= db
->db_data_pending
; dr
!= NULL
; dr
= dr
->dr_next
)
707 ASSERT(dr
->dr_dbuf
== db
);
709 for (dr
= db
->db_last_dirty
; dr
!= NULL
; dr
= dr
->dr_next
)
710 ASSERT(dr
->dr_dbuf
== db
);
713 * We can't assert that db_size matches dn_datablksz because it
714 * can be momentarily different when another thread is doing
717 if (db
->db_level
== 0 && db
->db
.db_object
== DMU_META_DNODE_OBJECT
) {
718 dr
= db
->db_data_pending
;
720 * It should only be modified in syncing context, so
721 * make sure we only have one copy of the data.
723 ASSERT(dr
== NULL
|| dr
->dt
.dl
.dr_data
== db
->db_buf
);
726 /* verify db->db_blkptr */
728 if (db
->db_parent
== dn
->dn_dbuf
) {
729 /* db is pointed to by the dnode */
730 /* ASSERT3U(db->db_blkid, <, dn->dn_nblkptr); */
731 if (DMU_OBJECT_IS_SPECIAL(db
->db
.db_object
))
732 ASSERT(db
->db_parent
== NULL
);
734 ASSERT(db
->db_parent
!= NULL
);
735 if (db
->db_blkid
!= DMU_SPILL_BLKID
)
736 ASSERT3P(db
->db_blkptr
, ==,
737 &dn
->dn_phys
->dn_blkptr
[db
->db_blkid
]);
739 /* db is pointed to by an indirect block */
740 int epb
= db
->db_parent
->db
.db_size
>> SPA_BLKPTRSHIFT
;
741 ASSERT3U(db
->db_parent
->db_level
, ==, db
->db_level
+1);
742 ASSERT3U(db
->db_parent
->db
.db_object
, ==,
745 * dnode_grow_indblksz() can make this fail if we don't
746 * have the struct_rwlock. XXX indblksz no longer
747 * grows. safe to do this now?
749 if (RW_WRITE_HELD(&dn
->dn_struct_rwlock
)) {
750 ASSERT3P(db
->db_blkptr
, ==,
751 ((blkptr_t
*)db
->db_parent
->db
.db_data
+
752 db
->db_blkid
% epb
));
756 if ((db
->db_blkptr
== NULL
|| BP_IS_HOLE(db
->db_blkptr
)) &&
757 (db
->db_buf
== NULL
|| db
->db_buf
->b_data
) &&
758 db
->db
.db_data
&& db
->db_blkid
!= DMU_BONUS_BLKID
&&
759 db
->db_state
!= DB_FILL
&& !dn
->dn_free_txg
) {
761 * If the blkptr isn't set but they have nonzero data,
762 * it had better be dirty, otherwise we'll lose that
763 * data when we evict this buffer.
765 * There is an exception to this rule for indirect blocks; in
766 * this case, if the indirect block is a hole, we fill in a few
767 * fields on each of the child blocks (importantly, birth time)
768 * to prevent hole birth times from being lost when you
769 * partially fill in a hole.
771 if (db
->db_dirtycnt
== 0) {
772 if (db
->db_level
== 0) {
773 uint64_t *buf
= db
->db
.db_data
;
776 for (i
= 0; i
< db
->db
.db_size
>> 3; i
++) {
780 blkptr_t
*bps
= db
->db
.db_data
;
781 ASSERT3U(1 << DB_DNODE(db
)->dn_indblkshift
, ==,
784 * We want to verify that all the blkptrs in the
785 * indirect block are holes, but we may have
786 * automatically set up a few fields for them.
787 * We iterate through each blkptr and verify
788 * they only have those fields set.
791 i
< db
->db
.db_size
/ sizeof (blkptr_t
);
793 blkptr_t
*bp
= &bps
[i
];
794 ASSERT(ZIO_CHECKSUM_IS_ZERO(
797 DVA_IS_EMPTY(&bp
->blk_dva
[0]) &&
798 DVA_IS_EMPTY(&bp
->blk_dva
[1]) &&
799 DVA_IS_EMPTY(&bp
->blk_dva
[2]));
800 ASSERT0(bp
->blk_fill
);
801 ASSERT0(bp
->blk_pad
[0]);
802 ASSERT0(bp
->blk_pad
[1]);
803 ASSERT(!BP_IS_EMBEDDED(bp
));
804 ASSERT(BP_IS_HOLE(bp
));
805 ASSERT0(bp
->blk_phys_birth
);
815 dbuf_clear_data(dmu_buf_impl_t
*db
)
817 ASSERT(MUTEX_HELD(&db
->db_mtx
));
819 ASSERT3P(db
->db_buf
, ==, NULL
);
820 db
->db
.db_data
= NULL
;
821 if (db
->db_state
!= DB_NOFILL
)
822 db
->db_state
= DB_UNCACHED
;
826 dbuf_set_data(dmu_buf_impl_t
*db
, arc_buf_t
*buf
)
828 ASSERT(MUTEX_HELD(&db
->db_mtx
));
832 ASSERT(buf
->b_data
!= NULL
);
833 db
->db
.db_data
= buf
->b_data
;
837 * Loan out an arc_buf for read. Return the loaned arc_buf.
840 dbuf_loan_arcbuf(dmu_buf_impl_t
*db
)
844 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
845 mutex_enter(&db
->db_mtx
);
846 if (arc_released(db
->db_buf
) || refcount_count(&db
->db_holds
) > 1) {
847 int blksz
= db
->db
.db_size
;
848 spa_t
*spa
= db
->db_objset
->os_spa
;
850 mutex_exit(&db
->db_mtx
);
851 abuf
= arc_loan_buf(spa
, B_FALSE
, blksz
);
852 bcopy(db
->db
.db_data
, abuf
->b_data
, blksz
);
855 arc_loan_inuse_buf(abuf
, db
);
858 mutex_exit(&db
->db_mtx
);
864 * Calculate which level n block references the data at the level 0 offset
868 dbuf_whichblock(dnode_t
*dn
, int64_t level
, uint64_t offset
)
870 if (dn
->dn_datablkshift
!= 0 && dn
->dn_indblkshift
!= 0) {
872 * The level n blkid is equal to the level 0 blkid divided by
873 * the number of level 0s in a level n block.
875 * The level 0 blkid is offset >> datablkshift =
876 * offset / 2^datablkshift.
878 * The number of level 0s in a level n is the number of block
879 * pointers in an indirect block, raised to the power of level.
880 * This is 2^(indblkshift - SPA_BLKPTRSHIFT)^level =
881 * 2^(level*(indblkshift - SPA_BLKPTRSHIFT)).
883 * Thus, the level n blkid is: offset /
884 * ((2^datablkshift)*(2^(level*(indblkshift - SPA_BLKPTRSHIFT)))
885 * = offset / 2^(datablkshift + level *
886 * (indblkshift - SPA_BLKPTRSHIFT))
887 * = offset >> (datablkshift + level *
888 * (indblkshift - SPA_BLKPTRSHIFT))
890 return (offset
>> (dn
->dn_datablkshift
+ level
*
891 (dn
->dn_indblkshift
- SPA_BLKPTRSHIFT
)));
893 ASSERT3U(offset
, <, dn
->dn_datablksz
);
899 dbuf_read_done(zio_t
*zio
, arc_buf_t
*buf
, void *vdb
)
901 dmu_buf_impl_t
*db
= vdb
;
903 mutex_enter(&db
->db_mtx
);
904 ASSERT3U(db
->db_state
, ==, DB_READ
);
906 * All reads are synchronous, so we must have a hold on the dbuf
908 ASSERT(refcount_count(&db
->db_holds
) > 0);
909 ASSERT(db
->db_buf
== NULL
);
910 ASSERT(db
->db
.db_data
== NULL
);
911 if (db
->db_level
== 0 && db
->db_freed_in_flight
) {
912 /* we were freed in flight; disregard any error */
913 arc_release(buf
, db
);
914 bzero(buf
->b_data
, db
->db
.db_size
);
916 db
->db_freed_in_flight
= FALSE
;
917 dbuf_set_data(db
, buf
);
918 db
->db_state
= DB_CACHED
;
919 } else if (zio
== NULL
|| zio
->io_error
== 0) {
920 dbuf_set_data(db
, buf
);
921 db
->db_state
= DB_CACHED
;
923 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
924 ASSERT3P(db
->db_buf
, ==, NULL
);
925 arc_buf_destroy(buf
, db
);
926 db
->db_state
= DB_UNCACHED
;
928 cv_broadcast(&db
->db_changed
);
929 dbuf_rele_and_unlock(db
, NULL
);
933 dbuf_read_impl(dmu_buf_impl_t
*db
, zio_t
*zio
, uint32_t flags
)
937 arc_flags_t aflags
= ARC_FLAG_NOWAIT
;
941 ASSERT(!refcount_is_zero(&db
->db_holds
));
942 /* We need the struct_rwlock to prevent db_blkptr from changing. */
943 ASSERT(RW_LOCK_HELD(&dn
->dn_struct_rwlock
));
944 ASSERT(MUTEX_HELD(&db
->db_mtx
));
945 ASSERT(db
->db_state
== DB_UNCACHED
);
946 ASSERT(db
->db_buf
== NULL
);
948 if (db
->db_blkid
== DMU_BONUS_BLKID
) {
949 int bonuslen
= MIN(dn
->dn_bonuslen
, dn
->dn_phys
->dn_bonuslen
);
951 ASSERT3U(bonuslen
, <=, db
->db
.db_size
);
952 db
->db
.db_data
= zio_buf_alloc(DN_MAX_BONUSLEN
);
953 arc_space_consume(DN_MAX_BONUSLEN
, ARC_SPACE_OTHER
);
954 if (bonuslen
< DN_MAX_BONUSLEN
)
955 bzero(db
->db
.db_data
, DN_MAX_BONUSLEN
);
957 bcopy(DN_BONUS(dn
->dn_phys
), db
->db
.db_data
, bonuslen
);
959 db
->db_state
= DB_CACHED
;
960 mutex_exit(&db
->db_mtx
);
965 * Recheck BP_IS_HOLE() after dnode_block_freed() in case dnode_sync()
966 * processes the delete record and clears the bp while we are waiting
967 * for the dn_mtx (resulting in a "no" from block_freed).
969 if (db
->db_blkptr
== NULL
|| BP_IS_HOLE(db
->db_blkptr
) ||
970 (db
->db_level
== 0 && (dnode_block_freed(dn
, db
->db_blkid
) ||
971 BP_IS_HOLE(db
->db_blkptr
)))) {
972 arc_buf_contents_t type
= DBUF_GET_BUFC_TYPE(db
);
974 dbuf_set_data(db
, arc_alloc_buf(db
->db_objset
->os_spa
, db
, type
,
976 bzero(db
->db
.db_data
, db
->db
.db_size
);
978 if (db
->db_blkptr
!= NULL
&& db
->db_level
> 0 &&
979 BP_IS_HOLE(db
->db_blkptr
) &&
980 db
->db_blkptr
->blk_birth
!= 0) {
981 blkptr_t
*bps
= db
->db
.db_data
;
982 for (int i
= 0; i
< ((1 <<
983 DB_DNODE(db
)->dn_indblkshift
) / sizeof (blkptr_t
));
985 blkptr_t
*bp
= &bps
[i
];
986 ASSERT3U(BP_GET_LSIZE(db
->db_blkptr
), ==,
987 1 << dn
->dn_indblkshift
);
989 BP_GET_LEVEL(db
->db_blkptr
) == 1 ?
991 BP_GET_LSIZE(db
->db_blkptr
));
992 BP_SET_TYPE(bp
, BP_GET_TYPE(db
->db_blkptr
));
994 BP_GET_LEVEL(db
->db_blkptr
) - 1);
995 BP_SET_BIRTH(bp
, db
->db_blkptr
->blk_birth
, 0);
999 db
->db_state
= DB_CACHED
;
1000 mutex_exit(&db
->db_mtx
);
1006 db
->db_state
= DB_READ
;
1007 mutex_exit(&db
->db_mtx
);
1009 if (DBUF_IS_L2CACHEABLE(db
))
1010 aflags
|= ARC_FLAG_L2CACHE
;
1012 SET_BOOKMARK(&zb
, db
->db_objset
->os_dsl_dataset
?
1013 db
->db_objset
->os_dsl_dataset
->ds_object
: DMU_META_OBJSET
,
1014 db
->db
.db_object
, db
->db_level
, db
->db_blkid
);
1016 dbuf_add_ref(db
, NULL
);
1018 (void) arc_read(zio
, db
->db_objset
->os_spa
, db
->db_blkptr
,
1019 dbuf_read_done
, db
, ZIO_PRIORITY_SYNC_READ
,
1020 (flags
& DB_RF_CANFAIL
) ? ZIO_FLAG_CANFAIL
: ZIO_FLAG_MUSTSUCCEED
,
1025 * This is our just-in-time copy function. It makes a copy of buffers that
1026 * have been modified in a previous transaction group before we access them in
1027 * the current active group.
1029 * This function is used in three places: when we are dirtying a buffer for the
1030 * first time in a txg, when we are freeing a range in a dnode that includes
1031 * this buffer, and when we are accessing a buffer which was received compressed
1032 * and later referenced in a WRITE_BYREF record.
1034 * Note that when we are called from dbuf_free_range() we do not put a hold on
1035 * the buffer, we just traverse the active dbuf list for the dnode.
1038 dbuf_fix_old_data(dmu_buf_impl_t
*db
, uint64_t txg
)
1040 dbuf_dirty_record_t
*dr
= db
->db_last_dirty
;
1042 ASSERT(MUTEX_HELD(&db
->db_mtx
));
1043 ASSERT(db
->db
.db_data
!= NULL
);
1044 ASSERT(db
->db_level
== 0);
1045 ASSERT(db
->db
.db_object
!= DMU_META_DNODE_OBJECT
);
1048 (dr
->dt
.dl
.dr_data
!=
1049 ((db
->db_blkid
== DMU_BONUS_BLKID
) ? db
->db
.db_data
: db
->db_buf
)))
1053 * If the last dirty record for this dbuf has not yet synced
1054 * and its referencing the dbuf data, either:
1055 * reset the reference to point to a new copy,
1056 * or (if there a no active holders)
1057 * just null out the current db_data pointer.
1059 ASSERT(dr
->dr_txg
>= txg
- 2);
1060 if (db
->db_blkid
== DMU_BONUS_BLKID
) {
1061 /* Note that the data bufs here are zio_bufs */
1062 dr
->dt
.dl
.dr_data
= zio_buf_alloc(DN_MAX_BONUSLEN
);
1063 arc_space_consume(DN_MAX_BONUSLEN
, ARC_SPACE_OTHER
);
1064 bcopy(db
->db
.db_data
, dr
->dt
.dl
.dr_data
, DN_MAX_BONUSLEN
);
1065 } else if (refcount_count(&db
->db_holds
) > db
->db_dirtycnt
) {
1066 int size
= arc_buf_size(db
->db_buf
);
1067 arc_buf_contents_t type
= DBUF_GET_BUFC_TYPE(db
);
1068 spa_t
*spa
= db
->db_objset
->os_spa
;
1069 enum zio_compress compress_type
=
1070 arc_get_compression(db
->db_buf
);
1072 if (compress_type
== ZIO_COMPRESS_OFF
) {
1073 dr
->dt
.dl
.dr_data
= arc_alloc_buf(spa
, db
, type
, size
);
1075 ASSERT3U(type
, ==, ARC_BUFC_DATA
);
1076 dr
->dt
.dl
.dr_data
= arc_alloc_compressed_buf(spa
, db
,
1077 size
, arc_buf_lsize(db
->db_buf
), compress_type
);
1079 bcopy(db
->db
.db_data
, dr
->dt
.dl
.dr_data
->b_data
, size
);
1082 dbuf_clear_data(db
);
1087 dbuf_read(dmu_buf_impl_t
*db
, zio_t
*zio
, uint32_t flags
)
1094 * We don't have to hold the mutex to check db_state because it
1095 * can't be freed while we have a hold on the buffer.
1097 ASSERT(!refcount_is_zero(&db
->db_holds
));
1099 if (db
->db_state
== DB_NOFILL
)
1100 return (SET_ERROR(EIO
));
1104 if ((flags
& DB_RF_HAVESTRUCT
) == 0)
1105 rw_enter(&dn
->dn_struct_rwlock
, RW_READER
);
1107 prefetch
= db
->db_level
== 0 && db
->db_blkid
!= DMU_BONUS_BLKID
&&
1108 (flags
& DB_RF_NOPREFETCH
) == 0 && dn
!= NULL
&&
1109 DBUF_IS_CACHEABLE(db
);
1111 mutex_enter(&db
->db_mtx
);
1112 if (db
->db_state
== DB_CACHED
) {
1114 * If the arc buf is compressed, we need to decompress it to
1115 * read the data. This could happen during the "zfs receive" of
1116 * a stream which is compressed and deduplicated.
1118 if (db
->db_buf
!= NULL
&&
1119 arc_get_compression(db
->db_buf
) != ZIO_COMPRESS_OFF
) {
1120 dbuf_fix_old_data(db
,
1121 spa_syncing_txg(dmu_objset_spa(db
->db_objset
)));
1122 err
= arc_decompress(db
->db_buf
);
1123 dbuf_set_data(db
, db
->db_buf
);
1125 mutex_exit(&db
->db_mtx
);
1127 dmu_zfetch(&dn
->dn_zfetch
, db
->db_blkid
, 1, B_TRUE
);
1128 if ((flags
& DB_RF_HAVESTRUCT
) == 0)
1129 rw_exit(&dn
->dn_struct_rwlock
);
1131 } else if (db
->db_state
== DB_UNCACHED
) {
1132 spa_t
*spa
= dn
->dn_objset
->os_spa
;
1133 boolean_t need_wait
= B_FALSE
;
1136 db
->db_blkptr
!= NULL
&& !BP_IS_HOLE(db
->db_blkptr
)) {
1137 zio
= zio_root(spa
, NULL
, NULL
, ZIO_FLAG_CANFAIL
);
1140 dbuf_read_impl(db
, zio
, flags
);
1142 /* dbuf_read_impl has dropped db_mtx for us */
1145 dmu_zfetch(&dn
->dn_zfetch
, db
->db_blkid
, 1, B_TRUE
);
1147 if ((flags
& DB_RF_HAVESTRUCT
) == 0)
1148 rw_exit(&dn
->dn_struct_rwlock
);
1152 err
= zio_wait(zio
);
1155 * Another reader came in while the dbuf was in flight
1156 * between UNCACHED and CACHED. Either a writer will finish
1157 * writing the buffer (sending the dbuf to CACHED) or the
1158 * first reader's request will reach the read_done callback
1159 * and send the dbuf to CACHED. Otherwise, a failure
1160 * occurred and the dbuf went to UNCACHED.
1162 mutex_exit(&db
->db_mtx
);
1164 dmu_zfetch(&dn
->dn_zfetch
, db
->db_blkid
, 1, B_TRUE
);
1165 if ((flags
& DB_RF_HAVESTRUCT
) == 0)
1166 rw_exit(&dn
->dn_struct_rwlock
);
1169 /* Skip the wait per the caller's request. */
1170 mutex_enter(&db
->db_mtx
);
1171 if ((flags
& DB_RF_NEVERWAIT
) == 0) {
1172 while (db
->db_state
== DB_READ
||
1173 db
->db_state
== DB_FILL
) {
1174 ASSERT(db
->db_state
== DB_READ
||
1175 (flags
& DB_RF_HAVESTRUCT
) == 0);
1176 DTRACE_PROBE2(blocked__read
, dmu_buf_impl_t
*,
1178 cv_wait(&db
->db_changed
, &db
->db_mtx
);
1180 if (db
->db_state
== DB_UNCACHED
)
1181 err
= SET_ERROR(EIO
);
1183 mutex_exit(&db
->db_mtx
);
1190 dbuf_noread(dmu_buf_impl_t
*db
)
1192 ASSERT(!refcount_is_zero(&db
->db_holds
));
1193 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
1194 mutex_enter(&db
->db_mtx
);
1195 while (db
->db_state
== DB_READ
|| db
->db_state
== DB_FILL
)
1196 cv_wait(&db
->db_changed
, &db
->db_mtx
);
1197 if (db
->db_state
== DB_UNCACHED
) {
1198 arc_buf_contents_t type
= DBUF_GET_BUFC_TYPE(db
);
1199 spa_t
*spa
= db
->db_objset
->os_spa
;
1201 ASSERT(db
->db_buf
== NULL
);
1202 ASSERT(db
->db
.db_data
== NULL
);
1203 dbuf_set_data(db
, arc_alloc_buf(spa
, db
, type
, db
->db
.db_size
));
1204 db
->db_state
= DB_FILL
;
1205 } else if (db
->db_state
== DB_NOFILL
) {
1206 dbuf_clear_data(db
);
1208 ASSERT3U(db
->db_state
, ==, DB_CACHED
);
1210 mutex_exit(&db
->db_mtx
);
1214 dbuf_unoverride(dbuf_dirty_record_t
*dr
)
1216 dmu_buf_impl_t
*db
= dr
->dr_dbuf
;
1217 blkptr_t
*bp
= &dr
->dt
.dl
.dr_overridden_by
;
1218 uint64_t txg
= dr
->dr_txg
;
1220 ASSERT(MUTEX_HELD(&db
->db_mtx
));
1222 * This assert is valid because dmu_sync() expects to be called by
1223 * a zilog's get_data while holding a range lock. This call only
1224 * comes from dbuf_dirty() callers who must also hold a range lock.
1226 ASSERT(dr
->dt
.dl
.dr_override_state
!= DR_IN_DMU_SYNC
);
1227 ASSERT(db
->db_level
== 0);
1229 if (db
->db_blkid
== DMU_BONUS_BLKID
||
1230 dr
->dt
.dl
.dr_override_state
== DR_NOT_OVERRIDDEN
)
1233 ASSERT(db
->db_data_pending
!= dr
);
1235 /* free this block */
1236 if (!BP_IS_HOLE(bp
) && !dr
->dt
.dl
.dr_nopwrite
)
1237 zio_free(db
->db_objset
->os_spa
, txg
, bp
);
1239 dr
->dt
.dl
.dr_override_state
= DR_NOT_OVERRIDDEN
;
1240 dr
->dt
.dl
.dr_nopwrite
= B_FALSE
;
1243 * Release the already-written buffer, so we leave it in
1244 * a consistent dirty state. Note that all callers are
1245 * modifying the buffer, so they will immediately do
1246 * another (redundant) arc_release(). Therefore, leave
1247 * the buf thawed to save the effort of freezing &
1248 * immediately re-thawing it.
1250 arc_release(dr
->dt
.dl
.dr_data
, db
);
1254 * Evict (if its unreferenced) or clear (if its referenced) any level-0
1255 * data blocks in the free range, so that any future readers will find
1259 dbuf_free_range(dnode_t
*dn
, uint64_t start_blkid
, uint64_t end_blkid
,
1262 dmu_buf_impl_t db_search
;
1263 dmu_buf_impl_t
*db
, *db_next
;
1264 uint64_t txg
= tx
->tx_txg
;
1267 if (end_blkid
> dn
->dn_maxblkid
&&
1268 !(start_blkid
== DMU_SPILL_BLKID
|| end_blkid
== DMU_SPILL_BLKID
))
1269 end_blkid
= dn
->dn_maxblkid
;
1270 dprintf_dnode(dn
, "start=%llu end=%llu\n", start_blkid
, end_blkid
);
1272 db_search
.db_level
= 0;
1273 db_search
.db_blkid
= start_blkid
;
1274 db_search
.db_state
= DB_SEARCH
;
1276 mutex_enter(&dn
->dn_dbufs_mtx
);
1277 db
= avl_find(&dn
->dn_dbufs
, &db_search
, &where
);
1278 ASSERT3P(db
, ==, NULL
);
1280 db
= avl_nearest(&dn
->dn_dbufs
, where
, AVL_AFTER
);
1282 for (; db
!= NULL
; db
= db_next
) {
1283 db_next
= AVL_NEXT(&dn
->dn_dbufs
, db
);
1284 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
1286 if (db
->db_level
!= 0 || db
->db_blkid
> end_blkid
) {
1289 ASSERT3U(db
->db_blkid
, >=, start_blkid
);
1291 /* found a level 0 buffer in the range */
1292 mutex_enter(&db
->db_mtx
);
1293 if (dbuf_undirty(db
, tx
)) {
1294 /* mutex has been dropped and dbuf destroyed */
1298 if (db
->db_state
== DB_UNCACHED
||
1299 db
->db_state
== DB_NOFILL
||
1300 db
->db_state
== DB_EVICTING
) {
1301 ASSERT(db
->db
.db_data
== NULL
);
1302 mutex_exit(&db
->db_mtx
);
1305 if (db
->db_state
== DB_READ
|| db
->db_state
== DB_FILL
) {
1306 /* will be handled in dbuf_read_done or dbuf_rele */
1307 db
->db_freed_in_flight
= TRUE
;
1308 mutex_exit(&db
->db_mtx
);
1311 if (refcount_count(&db
->db_holds
) == 0) {
1316 /* The dbuf is referenced */
1318 if (db
->db_last_dirty
!= NULL
) {
1319 dbuf_dirty_record_t
*dr
= db
->db_last_dirty
;
1321 if (dr
->dr_txg
== txg
) {
1323 * This buffer is "in-use", re-adjust the file
1324 * size to reflect that this buffer may
1325 * contain new data when we sync.
1327 if (db
->db_blkid
!= DMU_SPILL_BLKID
&&
1328 db
->db_blkid
> dn
->dn_maxblkid
)
1329 dn
->dn_maxblkid
= db
->db_blkid
;
1330 dbuf_unoverride(dr
);
1333 * This dbuf is not dirty in the open context.
1334 * Either uncache it (if its not referenced in
1335 * the open context) or reset its contents to
1338 dbuf_fix_old_data(db
, txg
);
1341 /* clear the contents if its cached */
1342 if (db
->db_state
== DB_CACHED
) {
1343 ASSERT(db
->db
.db_data
!= NULL
);
1344 arc_release(db
->db_buf
, db
);
1345 bzero(db
->db
.db_data
, db
->db
.db_size
);
1346 arc_buf_freeze(db
->db_buf
);
1349 mutex_exit(&db
->db_mtx
);
1351 mutex_exit(&dn
->dn_dbufs_mtx
);
1355 dbuf_new_size(dmu_buf_impl_t
*db
, int size
, dmu_tx_t
*tx
)
1357 arc_buf_t
*buf
, *obuf
;
1358 int osize
= db
->db
.db_size
;
1359 arc_buf_contents_t type
= DBUF_GET_BUFC_TYPE(db
);
1362 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
1367 /* XXX does *this* func really need the lock? */
1368 ASSERT(RW_WRITE_HELD(&dn
->dn_struct_rwlock
));
1371 * This call to dmu_buf_will_dirty() with the dn_struct_rwlock held
1372 * is OK, because there can be no other references to the db
1373 * when we are changing its size, so no concurrent DB_FILL can
1377 * XXX we should be doing a dbuf_read, checking the return
1378 * value and returning that up to our callers
1380 dmu_buf_will_dirty(&db
->db
, tx
);
1382 /* create the data buffer for the new block */
1383 buf
= arc_alloc_buf(dn
->dn_objset
->os_spa
, db
, type
, size
);
1385 /* copy old block data to the new block */
1387 bcopy(obuf
->b_data
, buf
->b_data
, MIN(osize
, size
));
1388 /* zero the remainder */
1390 bzero((uint8_t *)buf
->b_data
+ osize
, size
- osize
);
1392 mutex_enter(&db
->db_mtx
);
1393 dbuf_set_data(db
, buf
);
1394 arc_buf_destroy(obuf
, db
);
1395 db
->db
.db_size
= size
;
1397 if (db
->db_level
== 0) {
1398 ASSERT3U(db
->db_last_dirty
->dr_txg
, ==, tx
->tx_txg
);
1399 db
->db_last_dirty
->dt
.dl
.dr_data
= buf
;
1401 mutex_exit(&db
->db_mtx
);
1403 dmu_objset_willuse_space(dn
->dn_objset
, size
- osize
, tx
);
1408 dbuf_release_bp(dmu_buf_impl_t
*db
)
1410 objset_t
*os
= db
->db_objset
;
1412 ASSERT(dsl_pool_sync_context(dmu_objset_pool(os
)));
1413 ASSERT(arc_released(os
->os_phys_buf
) ||
1414 list_link_active(&os
->os_dsl_dataset
->ds_synced_link
));
1415 ASSERT(db
->db_parent
== NULL
|| arc_released(db
->db_parent
->db_buf
));
1417 (void) arc_release(db
->db_buf
, db
);
1421 * We already have a dirty record for this TXG, and we are being
1425 dbuf_redirty(dbuf_dirty_record_t
*dr
)
1427 dmu_buf_impl_t
*db
= dr
->dr_dbuf
;
1429 ASSERT(MUTEX_HELD(&db
->db_mtx
));
1431 if (db
->db_level
== 0 && db
->db_blkid
!= DMU_BONUS_BLKID
) {
1433 * If this buffer has already been written out,
1434 * we now need to reset its state.
1436 dbuf_unoverride(dr
);
1437 if (db
->db
.db_object
!= DMU_META_DNODE_OBJECT
&&
1438 db
->db_state
!= DB_NOFILL
) {
1439 /* Already released on initial dirty, so just thaw. */
1440 ASSERT(arc_released(db
->db_buf
));
1441 arc_buf_thaw(db
->db_buf
);
1446 dbuf_dirty_record_t
*
1447 dbuf_dirty(dmu_buf_impl_t
*db
, dmu_tx_t
*tx
)
1451 dbuf_dirty_record_t
**drp
, *dr
;
1452 int drop_struct_lock
= FALSE
;
1453 int txgoff
= tx
->tx_txg
& TXG_MASK
;
1455 ASSERT(tx
->tx_txg
!= 0);
1456 ASSERT(!refcount_is_zero(&db
->db_holds
));
1457 DMU_TX_DIRTY_BUF(tx
, db
);
1462 * Shouldn't dirty a regular buffer in syncing context. Private
1463 * objects may be dirtied in syncing context, but only if they
1464 * were already pre-dirtied in open context.
1467 if (dn
->dn_objset
->os_dsl_dataset
!= NULL
) {
1468 rrw_enter(&dn
->dn_objset
->os_dsl_dataset
->ds_bp_rwlock
,
1471 ASSERT(!dmu_tx_is_syncing(tx
) ||
1472 BP_IS_HOLE(dn
->dn_objset
->os_rootbp
) ||
1473 DMU_OBJECT_IS_SPECIAL(dn
->dn_object
) ||
1474 dn
->dn_objset
->os_dsl_dataset
== NULL
);
1475 if (dn
->dn_objset
->os_dsl_dataset
!= NULL
)
1476 rrw_exit(&dn
->dn_objset
->os_dsl_dataset
->ds_bp_rwlock
, FTAG
);
1479 * We make this assert for private objects as well, but after we
1480 * check if we're already dirty. They are allowed to re-dirty
1481 * in syncing context.
1483 ASSERT(dn
->dn_object
== DMU_META_DNODE_OBJECT
||
1484 dn
->dn_dirtyctx
== DN_UNDIRTIED
|| dn
->dn_dirtyctx
==
1485 (dmu_tx_is_syncing(tx
) ? DN_DIRTY_SYNC
: DN_DIRTY_OPEN
));
1487 mutex_enter(&db
->db_mtx
);
1489 * XXX make this true for indirects too? The problem is that
1490 * transactions created with dmu_tx_create_assigned() from
1491 * syncing context don't bother holding ahead.
1493 ASSERT(db
->db_level
!= 0 ||
1494 db
->db_state
== DB_CACHED
|| db
->db_state
== DB_FILL
||
1495 db
->db_state
== DB_NOFILL
);
1497 mutex_enter(&dn
->dn_mtx
);
1499 * Don't set dirtyctx to SYNC if we're just modifying this as we
1500 * initialize the objset.
1502 if (dn
->dn_dirtyctx
== DN_UNDIRTIED
) {
1503 if (dn
->dn_objset
->os_dsl_dataset
!= NULL
) {
1504 rrw_enter(&dn
->dn_objset
->os_dsl_dataset
->ds_bp_rwlock
,
1507 if (!BP_IS_HOLE(dn
->dn_objset
->os_rootbp
)) {
1508 dn
->dn_dirtyctx
= (dmu_tx_is_syncing(tx
) ?
1509 DN_DIRTY_SYNC
: DN_DIRTY_OPEN
);
1510 ASSERT(dn
->dn_dirtyctx_firstset
== NULL
);
1511 dn
->dn_dirtyctx_firstset
= kmem_alloc(1, KM_SLEEP
);
1513 if (dn
->dn_objset
->os_dsl_dataset
!= NULL
) {
1514 rrw_exit(&dn
->dn_objset
->os_dsl_dataset
->ds_bp_rwlock
,
1518 mutex_exit(&dn
->dn_mtx
);
1520 if (db
->db_blkid
== DMU_SPILL_BLKID
)
1521 dn
->dn_have_spill
= B_TRUE
;
1524 * If this buffer is already dirty, we're done.
1526 drp
= &db
->db_last_dirty
;
1527 ASSERT(*drp
== NULL
|| (*drp
)->dr_txg
<= tx
->tx_txg
||
1528 db
->db
.db_object
== DMU_META_DNODE_OBJECT
);
1529 while ((dr
= *drp
) != NULL
&& dr
->dr_txg
> tx
->tx_txg
)
1531 if (dr
&& dr
->dr_txg
== tx
->tx_txg
) {
1535 mutex_exit(&db
->db_mtx
);
1540 * Only valid if not already dirty.
1542 ASSERT(dn
->dn_object
== 0 ||
1543 dn
->dn_dirtyctx
== DN_UNDIRTIED
|| dn
->dn_dirtyctx
==
1544 (dmu_tx_is_syncing(tx
) ? DN_DIRTY_SYNC
: DN_DIRTY_OPEN
));
1546 ASSERT3U(dn
->dn_nlevels
, >, db
->db_level
);
1549 * We should only be dirtying in syncing context if it's the
1550 * mos or we're initializing the os or it's a special object.
1551 * However, we are allowed to dirty in syncing context provided
1552 * we already dirtied it in open context. Hence we must make
1553 * this assertion only if we're not already dirty.
1556 VERIFY3U(tx
->tx_txg
, <=, spa_final_dirty_txg(os
->os_spa
));
1558 if (dn
->dn_objset
->os_dsl_dataset
!= NULL
)
1559 rrw_enter(&os
->os_dsl_dataset
->ds_bp_rwlock
, RW_READER
, FTAG
);
1560 ASSERT(!dmu_tx_is_syncing(tx
) || DMU_OBJECT_IS_SPECIAL(dn
->dn_object
) ||
1561 os
->os_dsl_dataset
== NULL
|| BP_IS_HOLE(os
->os_rootbp
));
1562 if (dn
->dn_objset
->os_dsl_dataset
!= NULL
)
1563 rrw_exit(&os
->os_dsl_dataset
->ds_bp_rwlock
, FTAG
);
1565 ASSERT(db
->db
.db_size
!= 0);
1567 dprintf_dbuf(db
, "size=%llx\n", (u_longlong_t
)db
->db
.db_size
);
1569 if (db
->db_blkid
!= DMU_BONUS_BLKID
) {
1570 dmu_objset_willuse_space(os
, db
->db
.db_size
, tx
);
1574 * If this buffer is dirty in an old transaction group we need
1575 * to make a copy of it so that the changes we make in this
1576 * transaction group won't leak out when we sync the older txg.
1578 dr
= kmem_zalloc(sizeof (dbuf_dirty_record_t
), KM_SLEEP
);
1579 if (db
->db_level
== 0) {
1580 void *data_old
= db
->db_buf
;
1582 if (db
->db_state
!= DB_NOFILL
) {
1583 if (db
->db_blkid
== DMU_BONUS_BLKID
) {
1584 dbuf_fix_old_data(db
, tx
->tx_txg
);
1585 data_old
= db
->db
.db_data
;
1586 } else if (db
->db
.db_object
!= DMU_META_DNODE_OBJECT
) {
1588 * Release the data buffer from the cache so
1589 * that we can modify it without impacting
1590 * possible other users of this cached data
1591 * block. Note that indirect blocks and
1592 * private objects are not released until the
1593 * syncing state (since they are only modified
1596 arc_release(db
->db_buf
, db
);
1597 dbuf_fix_old_data(db
, tx
->tx_txg
);
1598 data_old
= db
->db_buf
;
1600 ASSERT(data_old
!= NULL
);
1602 dr
->dt
.dl
.dr_data
= data_old
;
1604 mutex_init(&dr
->dt
.di
.dr_mtx
, NULL
, MUTEX_DEFAULT
, NULL
);
1605 list_create(&dr
->dt
.di
.dr_children
,
1606 sizeof (dbuf_dirty_record_t
),
1607 offsetof(dbuf_dirty_record_t
, dr_dirty_node
));
1609 if (db
->db_blkid
!= DMU_BONUS_BLKID
&& os
->os_dsl_dataset
!= NULL
)
1610 dr
->dr_accounted
= db
->db
.db_size
;
1612 dr
->dr_txg
= tx
->tx_txg
;
1617 * We could have been freed_in_flight between the dbuf_noread
1618 * and dbuf_dirty. We win, as though the dbuf_noread() had
1619 * happened after the free.
1621 if (db
->db_level
== 0 && db
->db_blkid
!= DMU_BONUS_BLKID
&&
1622 db
->db_blkid
!= DMU_SPILL_BLKID
) {
1623 mutex_enter(&dn
->dn_mtx
);
1624 if (dn
->dn_free_ranges
[txgoff
] != NULL
) {
1625 range_tree_clear(dn
->dn_free_ranges
[txgoff
],
1628 mutex_exit(&dn
->dn_mtx
);
1629 db
->db_freed_in_flight
= FALSE
;
1633 * This buffer is now part of this txg
1635 dbuf_add_ref(db
, (void *)(uintptr_t)tx
->tx_txg
);
1636 db
->db_dirtycnt
+= 1;
1637 ASSERT3U(db
->db_dirtycnt
, <=, 3);
1639 mutex_exit(&db
->db_mtx
);
1641 if (db
->db_blkid
== DMU_BONUS_BLKID
||
1642 db
->db_blkid
== DMU_SPILL_BLKID
) {
1643 mutex_enter(&dn
->dn_mtx
);
1644 ASSERT(!list_link_active(&dr
->dr_dirty_node
));
1645 list_insert_tail(&dn
->dn_dirty_records
[txgoff
], dr
);
1646 mutex_exit(&dn
->dn_mtx
);
1647 dnode_setdirty(dn
, tx
);
1653 * The dn_struct_rwlock prevents db_blkptr from changing
1654 * due to a write from syncing context completing
1655 * while we are running, so we want to acquire it before
1656 * looking at db_blkptr.
1658 if (!RW_WRITE_HELD(&dn
->dn_struct_rwlock
)) {
1659 rw_enter(&dn
->dn_struct_rwlock
, RW_READER
);
1660 drop_struct_lock
= TRUE
;
1664 * We need to hold the dn_struct_rwlock to make this assertion,
1665 * because it protects dn_phys / dn_next_nlevels from changing.
1667 ASSERT((dn
->dn_phys
->dn_nlevels
== 0 && db
->db_level
== 0) ||
1668 dn
->dn_phys
->dn_nlevels
> db
->db_level
||
1669 dn
->dn_next_nlevels
[txgoff
] > db
->db_level
||
1670 dn
->dn_next_nlevels
[(tx
->tx_txg
-1) & TXG_MASK
] > db
->db_level
||
1671 dn
->dn_next_nlevels
[(tx
->tx_txg
-2) & TXG_MASK
] > db
->db_level
);
1674 * If we are overwriting a dedup BP, then unless it is snapshotted,
1675 * when we get to syncing context we will need to decrement its
1676 * refcount in the DDT. Prefetch the relevant DDT block so that
1677 * syncing context won't have to wait for the i/o.
1679 ddt_prefetch(os
->os_spa
, db
->db_blkptr
);
1681 if (db
->db_level
== 0) {
1682 dnode_new_blkid(dn
, db
->db_blkid
, tx
, drop_struct_lock
);
1683 ASSERT(dn
->dn_maxblkid
>= db
->db_blkid
);
1686 if (db
->db_level
+1 < dn
->dn_nlevels
) {
1687 dmu_buf_impl_t
*parent
= db
->db_parent
;
1688 dbuf_dirty_record_t
*di
;
1689 int parent_held
= FALSE
;
1691 if (db
->db_parent
== NULL
|| db
->db_parent
== dn
->dn_dbuf
) {
1692 int epbs
= dn
->dn_indblkshift
- SPA_BLKPTRSHIFT
;
1694 parent
= dbuf_hold_level(dn
, db
->db_level
+1,
1695 db
->db_blkid
>> epbs
, FTAG
);
1696 ASSERT(parent
!= NULL
);
1699 if (drop_struct_lock
)
1700 rw_exit(&dn
->dn_struct_rwlock
);
1701 ASSERT3U(db
->db_level
+1, ==, parent
->db_level
);
1702 di
= dbuf_dirty(parent
, tx
);
1704 dbuf_rele(parent
, FTAG
);
1706 mutex_enter(&db
->db_mtx
);
1708 * Since we've dropped the mutex, it's possible that
1709 * dbuf_undirty() might have changed this out from under us.
1711 if (db
->db_last_dirty
== dr
||
1712 dn
->dn_object
== DMU_META_DNODE_OBJECT
) {
1713 mutex_enter(&di
->dt
.di
.dr_mtx
);
1714 ASSERT3U(di
->dr_txg
, ==, tx
->tx_txg
);
1715 ASSERT(!list_link_active(&dr
->dr_dirty_node
));
1716 list_insert_tail(&di
->dt
.di
.dr_children
, dr
);
1717 mutex_exit(&di
->dt
.di
.dr_mtx
);
1720 mutex_exit(&db
->db_mtx
);
1722 ASSERT(db
->db_level
+1 == dn
->dn_nlevels
);
1723 ASSERT(db
->db_blkid
< dn
->dn_nblkptr
);
1724 ASSERT(db
->db_parent
== NULL
|| db
->db_parent
== dn
->dn_dbuf
);
1725 mutex_enter(&dn
->dn_mtx
);
1726 ASSERT(!list_link_active(&dr
->dr_dirty_node
));
1727 list_insert_tail(&dn
->dn_dirty_records
[txgoff
], dr
);
1728 mutex_exit(&dn
->dn_mtx
);
1729 if (drop_struct_lock
)
1730 rw_exit(&dn
->dn_struct_rwlock
);
1733 dnode_setdirty(dn
, tx
);
1739 * Undirty a buffer in the transaction group referenced by the given
1740 * transaction. Return whether this evicted the dbuf.
1743 dbuf_undirty(dmu_buf_impl_t
*db
, dmu_tx_t
*tx
)
1746 uint64_t txg
= tx
->tx_txg
;
1747 dbuf_dirty_record_t
*dr
, **drp
;
1752 * Due to our use of dn_nlevels below, this can only be called
1753 * in open context, unless we are operating on the MOS.
1754 * From syncing context, dn_nlevels may be different from the
1755 * dn_nlevels used when dbuf was dirtied.
1757 ASSERT(db
->db_objset
==
1758 dmu_objset_pool(db
->db_objset
)->dp_meta_objset
||
1759 txg
!= spa_syncing_txg(dmu_objset_spa(db
->db_objset
)));
1760 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
1761 ASSERT0(db
->db_level
);
1762 ASSERT(MUTEX_HELD(&db
->db_mtx
));
1765 * If this buffer is not dirty, we're done.
1767 for (drp
= &db
->db_last_dirty
; (dr
= *drp
) != NULL
; drp
= &dr
->dr_next
)
1768 if (dr
->dr_txg
<= txg
)
1770 if (dr
== NULL
|| dr
->dr_txg
< txg
)
1772 ASSERT(dr
->dr_txg
== txg
);
1773 ASSERT(dr
->dr_dbuf
== db
);
1778 dprintf_dbuf(db
, "size=%llx\n", (u_longlong_t
)db
->db
.db_size
);
1780 ASSERT(db
->db
.db_size
!= 0);
1782 dsl_pool_undirty_space(dmu_objset_pool(dn
->dn_objset
),
1783 dr
->dr_accounted
, txg
);
1788 * Note that there are three places in dbuf_dirty()
1789 * where this dirty record may be put on a list.
1790 * Make sure to do a list_remove corresponding to
1791 * every one of those list_insert calls.
1793 if (dr
->dr_parent
) {
1794 mutex_enter(&dr
->dr_parent
->dt
.di
.dr_mtx
);
1795 list_remove(&dr
->dr_parent
->dt
.di
.dr_children
, dr
);
1796 mutex_exit(&dr
->dr_parent
->dt
.di
.dr_mtx
);
1797 } else if (db
->db_blkid
== DMU_SPILL_BLKID
||
1798 db
->db_level
+ 1 == dn
->dn_nlevels
) {
1799 ASSERT(db
->db_blkptr
== NULL
|| db
->db_parent
== dn
->dn_dbuf
);
1800 mutex_enter(&dn
->dn_mtx
);
1801 list_remove(&dn
->dn_dirty_records
[txg
& TXG_MASK
], dr
);
1802 mutex_exit(&dn
->dn_mtx
);
1806 if (db
->db_state
!= DB_NOFILL
) {
1807 dbuf_unoverride(dr
);
1809 ASSERT(db
->db_buf
!= NULL
);
1810 ASSERT(dr
->dt
.dl
.dr_data
!= NULL
);
1811 if (dr
->dt
.dl
.dr_data
!= db
->db_buf
)
1812 arc_buf_destroy(dr
->dt
.dl
.dr_data
, db
);
1815 kmem_free(dr
, sizeof (dbuf_dirty_record_t
));
1817 ASSERT(db
->db_dirtycnt
> 0);
1818 db
->db_dirtycnt
-= 1;
1820 if (refcount_remove(&db
->db_holds
, (void *)(uintptr_t)txg
) == 0) {
1821 ASSERT(db
->db_state
== DB_NOFILL
|| arc_released(db
->db_buf
));
1830 dmu_buf_will_dirty(dmu_buf_t
*db_fake
, dmu_tx_t
*tx
)
1832 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)db_fake
;
1833 int rf
= DB_RF_MUST_SUCCEED
| DB_RF_NOPREFETCH
;
1835 ASSERT(tx
->tx_txg
!= 0);
1836 ASSERT(!refcount_is_zero(&db
->db_holds
));
1839 * Quick check for dirtyness. For already dirty blocks, this
1840 * reduces runtime of this function by >90%, and overall performance
1841 * by 50% for some workloads (e.g. file deletion with indirect blocks
1844 mutex_enter(&db
->db_mtx
);
1845 dbuf_dirty_record_t
*dr
;
1846 for (dr
= db
->db_last_dirty
;
1847 dr
!= NULL
&& dr
->dr_txg
>= tx
->tx_txg
; dr
= dr
->dr_next
) {
1849 * It's possible that it is already dirty but not cached,
1850 * because there are some calls to dbuf_dirty() that don't
1851 * go through dmu_buf_will_dirty().
1853 if (dr
->dr_txg
== tx
->tx_txg
&& db
->db_state
== DB_CACHED
) {
1854 /* This dbuf is already dirty and cached. */
1856 mutex_exit(&db
->db_mtx
);
1860 mutex_exit(&db
->db_mtx
);
1863 if (RW_WRITE_HELD(&DB_DNODE(db
)->dn_struct_rwlock
))
1864 rf
|= DB_RF_HAVESTRUCT
;
1866 (void) dbuf_read(db
, NULL
, rf
);
1867 (void) dbuf_dirty(db
, tx
);
1871 dmu_buf_will_not_fill(dmu_buf_t
*db_fake
, dmu_tx_t
*tx
)
1873 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)db_fake
;
1875 db
->db_state
= DB_NOFILL
;
1877 dmu_buf_will_fill(db_fake
, tx
);
1881 dmu_buf_will_fill(dmu_buf_t
*db_fake
, dmu_tx_t
*tx
)
1883 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)db_fake
;
1885 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
1886 ASSERT(tx
->tx_txg
!= 0);
1887 ASSERT(db
->db_level
== 0);
1888 ASSERT(!refcount_is_zero(&db
->db_holds
));
1890 ASSERT(db
->db
.db_object
!= DMU_META_DNODE_OBJECT
||
1891 dmu_tx_private_ok(tx
));
1894 (void) dbuf_dirty(db
, tx
);
1897 #pragma weak dmu_buf_fill_done = dbuf_fill_done
1900 dbuf_fill_done(dmu_buf_impl_t
*db
, dmu_tx_t
*tx
)
1902 mutex_enter(&db
->db_mtx
);
1905 if (db
->db_state
== DB_FILL
) {
1906 if (db
->db_level
== 0 && db
->db_freed_in_flight
) {
1907 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
1908 /* we were freed while filling */
1909 /* XXX dbuf_undirty? */
1910 bzero(db
->db
.db_data
, db
->db
.db_size
);
1911 db
->db_freed_in_flight
= FALSE
;
1913 db
->db_state
= DB_CACHED
;
1914 cv_broadcast(&db
->db_changed
);
1916 mutex_exit(&db
->db_mtx
);
1920 dmu_buf_write_embedded(dmu_buf_t
*dbuf
, void *data
,
1921 bp_embedded_type_t etype
, enum zio_compress comp
,
1922 int uncompressed_size
, int compressed_size
, int byteorder
,
1925 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)dbuf
;
1926 struct dirty_leaf
*dl
;
1927 dmu_object_type_t type
;
1929 if (etype
== BP_EMBEDDED_TYPE_DATA
) {
1930 ASSERT(spa_feature_is_active(dmu_objset_spa(db
->db_objset
),
1931 SPA_FEATURE_EMBEDDED_DATA
));
1935 type
= DB_DNODE(db
)->dn_type
;
1938 ASSERT0(db
->db_level
);
1939 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
1941 dmu_buf_will_not_fill(dbuf
, tx
);
1943 ASSERT3U(db
->db_last_dirty
->dr_txg
, ==, tx
->tx_txg
);
1944 dl
= &db
->db_last_dirty
->dt
.dl
;
1945 encode_embedded_bp_compressed(&dl
->dr_overridden_by
,
1946 data
, comp
, uncompressed_size
, compressed_size
);
1947 BPE_SET_ETYPE(&dl
->dr_overridden_by
, etype
);
1948 BP_SET_TYPE(&dl
->dr_overridden_by
, type
);
1949 BP_SET_LEVEL(&dl
->dr_overridden_by
, 0);
1950 BP_SET_BYTEORDER(&dl
->dr_overridden_by
, byteorder
);
1952 dl
->dr_override_state
= DR_OVERRIDDEN
;
1953 dl
->dr_overridden_by
.blk_birth
= db
->db_last_dirty
->dr_txg
;
1957 * Directly assign a provided arc buf to a given dbuf if it's not referenced
1958 * by anybody except our caller. Otherwise copy arcbuf's contents to dbuf.
1961 dbuf_assign_arcbuf(dmu_buf_impl_t
*db
, arc_buf_t
*buf
, dmu_tx_t
*tx
)
1963 ASSERT(!refcount_is_zero(&db
->db_holds
));
1964 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
1965 ASSERT(db
->db_level
== 0);
1966 ASSERT3U(dbuf_is_metadata(db
), ==, arc_is_metadata(buf
));
1967 ASSERT(buf
!= NULL
);
1968 ASSERT(arc_buf_lsize(buf
) == db
->db
.db_size
);
1969 ASSERT(tx
->tx_txg
!= 0);
1971 arc_return_buf(buf
, db
);
1972 ASSERT(arc_released(buf
));
1974 mutex_enter(&db
->db_mtx
);
1976 while (db
->db_state
== DB_READ
|| db
->db_state
== DB_FILL
)
1977 cv_wait(&db
->db_changed
, &db
->db_mtx
);
1979 ASSERT(db
->db_state
== DB_CACHED
|| db
->db_state
== DB_UNCACHED
);
1981 if (db
->db_state
== DB_CACHED
&&
1982 refcount_count(&db
->db_holds
) - 1 > db
->db_dirtycnt
) {
1983 mutex_exit(&db
->db_mtx
);
1984 (void) dbuf_dirty(db
, tx
);
1985 bcopy(buf
->b_data
, db
->db
.db_data
, db
->db
.db_size
);
1986 arc_buf_destroy(buf
, db
);
1987 xuio_stat_wbuf_copied();
1991 xuio_stat_wbuf_nocopy();
1992 if (db
->db_state
== DB_CACHED
) {
1993 dbuf_dirty_record_t
*dr
= db
->db_last_dirty
;
1995 ASSERT(db
->db_buf
!= NULL
);
1996 if (dr
!= NULL
&& dr
->dr_txg
== tx
->tx_txg
) {
1997 ASSERT(dr
->dt
.dl
.dr_data
== db
->db_buf
);
1998 if (!arc_released(db
->db_buf
)) {
1999 ASSERT(dr
->dt
.dl
.dr_override_state
==
2001 arc_release(db
->db_buf
, db
);
2003 dr
->dt
.dl
.dr_data
= buf
;
2004 arc_buf_destroy(db
->db_buf
, db
);
2005 } else if (dr
== NULL
|| dr
->dt
.dl
.dr_data
!= db
->db_buf
) {
2006 arc_release(db
->db_buf
, db
);
2007 arc_buf_destroy(db
->db_buf
, db
);
2011 ASSERT(db
->db_buf
== NULL
);
2012 dbuf_set_data(db
, buf
);
2013 db
->db_state
= DB_FILL
;
2014 mutex_exit(&db
->db_mtx
);
2015 (void) dbuf_dirty(db
, tx
);
2016 dmu_buf_fill_done(&db
->db
, tx
);
2020 dbuf_destroy(dmu_buf_impl_t
*db
)
2023 dmu_buf_impl_t
*parent
= db
->db_parent
;
2024 dmu_buf_impl_t
*dndb
;
2026 ASSERT(MUTEX_HELD(&db
->db_mtx
));
2027 ASSERT(refcount_is_zero(&db
->db_holds
));
2029 if (db
->db_buf
!= NULL
) {
2030 arc_buf_destroy(db
->db_buf
, db
);
2034 if (db
->db_blkid
== DMU_BONUS_BLKID
) {
2035 ASSERT(db
->db
.db_data
!= NULL
);
2036 zio_buf_free(db
->db
.db_data
, DN_MAX_BONUSLEN
);
2037 arc_space_return(DN_MAX_BONUSLEN
, ARC_SPACE_OTHER
);
2038 db
->db_state
= DB_UNCACHED
;
2041 dbuf_clear_data(db
);
2043 if (multilist_link_active(&db
->db_cache_link
)) {
2044 multilist_remove(dbuf_cache
, db
);
2045 (void) refcount_remove_many(&dbuf_cache_size
,
2046 db
->db
.db_size
, db
);
2049 ASSERT(db
->db_state
== DB_UNCACHED
|| db
->db_state
== DB_NOFILL
);
2050 ASSERT(db
->db_data_pending
== NULL
);
2052 db
->db_state
= DB_EVICTING
;
2053 db
->db_blkptr
= NULL
;
2056 * Now that db_state is DB_EVICTING, nobody else can find this via
2057 * the hash table. We can now drop db_mtx, which allows us to
2058 * acquire the dn_dbufs_mtx.
2060 mutex_exit(&db
->db_mtx
);
2065 if (db
->db_blkid
!= DMU_BONUS_BLKID
) {
2066 boolean_t needlock
= !MUTEX_HELD(&dn
->dn_dbufs_mtx
);
2068 mutex_enter(&dn
->dn_dbufs_mtx
);
2069 avl_remove(&dn
->dn_dbufs
, db
);
2070 atomic_dec_32(&dn
->dn_dbufs_count
);
2074 mutex_exit(&dn
->dn_dbufs_mtx
);
2076 * Decrementing the dbuf count means that the hold corresponding
2077 * to the removed dbuf is no longer discounted in dnode_move(),
2078 * so the dnode cannot be moved until after we release the hold.
2079 * The membar_producer() ensures visibility of the decremented
2080 * value in dnode_move(), since DB_DNODE_EXIT doesn't actually
2084 db
->db_dnode_handle
= NULL
;
2086 dbuf_hash_remove(db
);
2091 ASSERT(refcount_is_zero(&db
->db_holds
));
2093 db
->db_parent
= NULL
;
2095 ASSERT(db
->db_buf
== NULL
);
2096 ASSERT(db
->db
.db_data
== NULL
);
2097 ASSERT(db
->db_hash_next
== NULL
);
2098 ASSERT(db
->db_blkptr
== NULL
);
2099 ASSERT(db
->db_data_pending
== NULL
);
2100 ASSERT(!multilist_link_active(&db
->db_cache_link
));
2102 kmem_cache_free(dbuf_kmem_cache
, db
);
2103 arc_space_return(sizeof (dmu_buf_impl_t
), ARC_SPACE_OTHER
);
2106 * If this dbuf is referenced from an indirect dbuf,
2107 * decrement the ref count on the indirect dbuf.
2109 if (parent
&& parent
!= dndb
)
2110 dbuf_rele(parent
, db
);
2114 * Note: While bpp will always be updated if the function returns success,
2115 * parentp will not be updated if the dnode does not have dn_dbuf filled in;
2116 * this happens when the dnode is the meta-dnode, or a userused or groupused
2120 dbuf_findbp(dnode_t
*dn
, int level
, uint64_t blkid
, int fail_sparse
,
2121 dmu_buf_impl_t
**parentp
, blkptr_t
**bpp
)
2126 ASSERT(blkid
!= DMU_BONUS_BLKID
);
2128 if (blkid
== DMU_SPILL_BLKID
) {
2129 mutex_enter(&dn
->dn_mtx
);
2130 if (dn
->dn_have_spill
&&
2131 (dn
->dn_phys
->dn_flags
& DNODE_FLAG_SPILL_BLKPTR
))
2132 *bpp
= &dn
->dn_phys
->dn_spill
;
2135 dbuf_add_ref(dn
->dn_dbuf
, NULL
);
2136 *parentp
= dn
->dn_dbuf
;
2137 mutex_exit(&dn
->dn_mtx
);
2142 (dn
->dn_phys
->dn_nlevels
== 0) ? 1 : dn
->dn_phys
->dn_nlevels
;
2143 int epbs
= dn
->dn_indblkshift
- SPA_BLKPTRSHIFT
;
2145 ASSERT3U(level
* epbs
, <, 64);
2146 ASSERT(RW_LOCK_HELD(&dn
->dn_struct_rwlock
));
2148 * This assertion shouldn't trip as long as the max indirect block size
2149 * is less than 1M. The reason for this is that up to that point,
2150 * the number of levels required to address an entire object with blocks
2151 * of size SPA_MINBLOCKSIZE satisfies nlevels * epbs + 1 <= 64. In
2152 * other words, if N * epbs + 1 > 64, then if (N-1) * epbs + 1 > 55
2153 * (i.e. we can address the entire object), objects will all use at most
2154 * N-1 levels and the assertion won't overflow. However, once epbs is
2155 * 13, 4 * 13 + 1 = 53, but 5 * 13 + 1 = 66. Then, 4 levels will not be
2156 * enough to address an entire object, so objects will have 5 levels,
2157 * but then this assertion will overflow.
2159 * All this is to say that if we ever increase DN_MAX_INDBLKSHIFT, we
2160 * need to redo this logic to handle overflows.
2162 ASSERT(level
>= nlevels
||
2163 ((nlevels
- level
- 1) * epbs
) +
2164 highbit64(dn
->dn_phys
->dn_nblkptr
) <= 64);
2165 if (level
>= nlevels
||
2166 blkid
>= ((uint64_t)dn
->dn_phys
->dn_nblkptr
<<
2167 ((nlevels
- level
- 1) * epbs
)) ||
2169 blkid
> (dn
->dn_phys
->dn_maxblkid
>> (level
* epbs
)))) {
2170 /* the buffer has no parent yet */
2171 return (SET_ERROR(ENOENT
));
2172 } else if (level
< nlevels
-1) {
2173 /* this block is referenced from an indirect block */
2174 int err
= dbuf_hold_impl(dn
, level
+1,
2175 blkid
>> epbs
, fail_sparse
, FALSE
, NULL
, parentp
);
2178 err
= dbuf_read(*parentp
, NULL
,
2179 (DB_RF_HAVESTRUCT
| DB_RF_NOPREFETCH
| DB_RF_CANFAIL
));
2181 dbuf_rele(*parentp
, NULL
);
2185 *bpp
= ((blkptr_t
*)(*parentp
)->db
.db_data
) +
2186 (blkid
& ((1ULL << epbs
) - 1));
2187 if (blkid
> (dn
->dn_phys
->dn_maxblkid
>> (level
* epbs
)))
2188 ASSERT(BP_IS_HOLE(*bpp
));
2191 /* the block is referenced from the dnode */
2192 ASSERT3U(level
, ==, nlevels
-1);
2193 ASSERT(dn
->dn_phys
->dn_nblkptr
== 0 ||
2194 blkid
< dn
->dn_phys
->dn_nblkptr
);
2196 dbuf_add_ref(dn
->dn_dbuf
, NULL
);
2197 *parentp
= dn
->dn_dbuf
;
2199 *bpp
= &dn
->dn_phys
->dn_blkptr
[blkid
];
2204 static dmu_buf_impl_t
*
2205 dbuf_create(dnode_t
*dn
, uint8_t level
, uint64_t blkid
,
2206 dmu_buf_impl_t
*parent
, blkptr_t
*blkptr
)
2208 objset_t
*os
= dn
->dn_objset
;
2209 dmu_buf_impl_t
*db
, *odb
;
2211 ASSERT(RW_LOCK_HELD(&dn
->dn_struct_rwlock
));
2212 ASSERT(dn
->dn_type
!= DMU_OT_NONE
);
2214 db
= kmem_cache_alloc(dbuf_kmem_cache
, KM_SLEEP
);
2217 db
->db
.db_object
= dn
->dn_object
;
2218 db
->db_level
= level
;
2219 db
->db_blkid
= blkid
;
2220 db
->db_last_dirty
= NULL
;
2221 db
->db_dirtycnt
= 0;
2222 db
->db_dnode_handle
= dn
->dn_handle
;
2223 db
->db_parent
= parent
;
2224 db
->db_blkptr
= blkptr
;
2227 db
->db_user_immediate_evict
= FALSE
;
2228 db
->db_freed_in_flight
= FALSE
;
2229 db
->db_pending_evict
= FALSE
;
2231 if (blkid
== DMU_BONUS_BLKID
) {
2232 ASSERT3P(parent
, ==, dn
->dn_dbuf
);
2233 db
->db
.db_size
= DN_MAX_BONUSLEN
-
2234 (dn
->dn_nblkptr
-1) * sizeof (blkptr_t
);
2235 ASSERT3U(db
->db
.db_size
, >=, dn
->dn_bonuslen
);
2236 db
->db
.db_offset
= DMU_BONUS_BLKID
;
2237 db
->db_state
= DB_UNCACHED
;
2238 /* the bonus dbuf is not placed in the hash table */
2239 arc_space_consume(sizeof (dmu_buf_impl_t
), ARC_SPACE_OTHER
);
2241 } else if (blkid
== DMU_SPILL_BLKID
) {
2242 db
->db
.db_size
= (blkptr
!= NULL
) ?
2243 BP_GET_LSIZE(blkptr
) : SPA_MINBLOCKSIZE
;
2244 db
->db
.db_offset
= 0;
2247 db
->db_level
? 1 << dn
->dn_indblkshift
: dn
->dn_datablksz
;
2248 db
->db
.db_size
= blocksize
;
2249 db
->db
.db_offset
= db
->db_blkid
* blocksize
;
2253 * Hold the dn_dbufs_mtx while we get the new dbuf
2254 * in the hash table *and* added to the dbufs list.
2255 * This prevents a possible deadlock with someone
2256 * trying to look up this dbuf before its added to the
2259 mutex_enter(&dn
->dn_dbufs_mtx
);
2260 db
->db_state
= DB_EVICTING
;
2261 if ((odb
= dbuf_hash_insert(db
)) != NULL
) {
2262 /* someone else inserted it first */
2263 kmem_cache_free(dbuf_kmem_cache
, db
);
2264 mutex_exit(&dn
->dn_dbufs_mtx
);
2267 avl_add(&dn
->dn_dbufs
, db
);
2269 db
->db_state
= DB_UNCACHED
;
2270 mutex_exit(&dn
->dn_dbufs_mtx
);
2271 arc_space_consume(sizeof (dmu_buf_impl_t
), ARC_SPACE_OTHER
);
2273 if (parent
&& parent
!= dn
->dn_dbuf
)
2274 dbuf_add_ref(parent
, db
);
2276 ASSERT(dn
->dn_object
== DMU_META_DNODE_OBJECT
||
2277 refcount_count(&dn
->dn_holds
) > 0);
2278 (void) refcount_add(&dn
->dn_holds
, db
);
2279 atomic_inc_32(&dn
->dn_dbufs_count
);
2281 dprintf_dbuf(db
, "db=%p\n", db
);
2286 typedef struct dbuf_prefetch_arg
{
2287 spa_t
*dpa_spa
; /* The spa to issue the prefetch in. */
2288 zbookmark_phys_t dpa_zb
; /* The target block to prefetch. */
2289 int dpa_epbs
; /* Entries (blkptr_t's) Per Block Shift. */
2290 int dpa_curlevel
; /* The current level that we're reading */
2291 dnode_t
*dpa_dnode
; /* The dnode associated with the prefetch */
2292 zio_priority_t dpa_prio
; /* The priority I/Os should be issued at. */
2293 zio_t
*dpa_zio
; /* The parent zio_t for all prefetches. */
2294 arc_flags_t dpa_aflags
; /* Flags to pass to the final prefetch. */
2295 } dbuf_prefetch_arg_t
;
2298 * Actually issue the prefetch read for the block given.
2301 dbuf_issue_final_prefetch(dbuf_prefetch_arg_t
*dpa
, blkptr_t
*bp
)
2303 if (BP_IS_HOLE(bp
) || BP_IS_EMBEDDED(bp
))
2306 arc_flags_t aflags
=
2307 dpa
->dpa_aflags
| ARC_FLAG_NOWAIT
| ARC_FLAG_PREFETCH
;
2309 ASSERT3U(dpa
->dpa_curlevel
, ==, BP_GET_LEVEL(bp
));
2310 ASSERT3U(dpa
->dpa_curlevel
, ==, dpa
->dpa_zb
.zb_level
);
2311 ASSERT(dpa
->dpa_zio
!= NULL
);
2312 (void) arc_read(dpa
->dpa_zio
, dpa
->dpa_spa
, bp
, NULL
, NULL
,
2313 dpa
->dpa_prio
, ZIO_FLAG_CANFAIL
| ZIO_FLAG_SPECULATIVE
,
2314 &aflags
, &dpa
->dpa_zb
);
2318 * Called when an indirect block above our prefetch target is read in. This
2319 * will either read in the next indirect block down the tree or issue the actual
2320 * prefetch if the next block down is our target.
2323 dbuf_prefetch_indirect_done(zio_t
*zio
, arc_buf_t
*abuf
, void *private)
2325 dbuf_prefetch_arg_t
*dpa
= private;
2327 ASSERT3S(dpa
->dpa_zb
.zb_level
, <, dpa
->dpa_curlevel
);
2328 ASSERT3S(dpa
->dpa_curlevel
, >, 0);
2331 * The dpa_dnode is only valid if we are called with a NULL
2332 * zio. This indicates that the arc_read() returned without
2333 * first calling zio_read() to issue a physical read. Once
2334 * a physical read is made the dpa_dnode must be invalidated
2335 * as the locks guarding it may have been dropped. If the
2336 * dpa_dnode is still valid, then we want to add it to the dbuf
2337 * cache. To do so, we must hold the dbuf associated with the block
2338 * we just prefetched, read its contents so that we associate it
2339 * with an arc_buf_t, and then release it.
2342 ASSERT3S(BP_GET_LEVEL(zio
->io_bp
), ==, dpa
->dpa_curlevel
);
2343 if (zio
->io_flags
& ZIO_FLAG_RAW
) {
2344 ASSERT3U(BP_GET_PSIZE(zio
->io_bp
), ==, zio
->io_size
);
2346 ASSERT3U(BP_GET_LSIZE(zio
->io_bp
), ==, zio
->io_size
);
2348 ASSERT3P(zio
->io_spa
, ==, dpa
->dpa_spa
);
2350 dpa
->dpa_dnode
= NULL
;
2351 } else if (dpa
->dpa_dnode
!= NULL
) {
2352 uint64_t curblkid
= dpa
->dpa_zb
.zb_blkid
>>
2353 (dpa
->dpa_epbs
* (dpa
->dpa_curlevel
-
2354 dpa
->dpa_zb
.zb_level
));
2355 dmu_buf_impl_t
*db
= dbuf_hold_level(dpa
->dpa_dnode
,
2356 dpa
->dpa_curlevel
, curblkid
, FTAG
);
2357 (void) dbuf_read(db
, NULL
,
2358 DB_RF_MUST_SUCCEED
| DB_RF_NOPREFETCH
| DB_RF_HAVESTRUCT
);
2359 dbuf_rele(db
, FTAG
);
2362 dpa
->dpa_curlevel
--;
2364 uint64_t nextblkid
= dpa
->dpa_zb
.zb_blkid
>>
2365 (dpa
->dpa_epbs
* (dpa
->dpa_curlevel
- dpa
->dpa_zb
.zb_level
));
2366 blkptr_t
*bp
= ((blkptr_t
*)abuf
->b_data
) +
2367 P2PHASE(nextblkid
, 1ULL << dpa
->dpa_epbs
);
2368 if (BP_IS_HOLE(bp
) || (zio
!= NULL
&& zio
->io_error
!= 0)) {
2369 kmem_free(dpa
, sizeof (*dpa
));
2370 } else if (dpa
->dpa_curlevel
== dpa
->dpa_zb
.zb_level
) {
2371 ASSERT3U(nextblkid
, ==, dpa
->dpa_zb
.zb_blkid
);
2372 dbuf_issue_final_prefetch(dpa
, bp
);
2373 kmem_free(dpa
, sizeof (*dpa
));
2375 arc_flags_t iter_aflags
= ARC_FLAG_NOWAIT
;
2376 zbookmark_phys_t zb
;
2378 /* flag if L2ARC eligible, l2arc_noprefetch then decides */
2379 if (dpa
->dpa_aflags
& ARC_FLAG_L2CACHE
)
2380 iter_aflags
|= ARC_FLAG_L2CACHE
;
2382 ASSERT3U(dpa
->dpa_curlevel
, ==, BP_GET_LEVEL(bp
));
2384 SET_BOOKMARK(&zb
, dpa
->dpa_zb
.zb_objset
,
2385 dpa
->dpa_zb
.zb_object
, dpa
->dpa_curlevel
, nextblkid
);
2387 (void) arc_read(dpa
->dpa_zio
, dpa
->dpa_spa
,
2388 bp
, dbuf_prefetch_indirect_done
, dpa
, dpa
->dpa_prio
,
2389 ZIO_FLAG_CANFAIL
| ZIO_FLAG_SPECULATIVE
,
2393 arc_buf_destroy(abuf
, private);
2397 * Issue prefetch reads for the given block on the given level. If the indirect
2398 * blocks above that block are not in memory, we will read them in
2399 * asynchronously. As a result, this call never blocks waiting for a read to
2403 dbuf_prefetch(dnode_t
*dn
, int64_t level
, uint64_t blkid
, zio_priority_t prio
,
2407 int epbs
, nlevels
, curlevel
;
2410 ASSERT(blkid
!= DMU_BONUS_BLKID
);
2411 ASSERT(RW_LOCK_HELD(&dn
->dn_struct_rwlock
));
2413 if (blkid
> dn
->dn_maxblkid
)
2416 if (dnode_block_freed(dn
, blkid
))
2420 * This dnode hasn't been written to disk yet, so there's nothing to
2423 nlevels
= dn
->dn_phys
->dn_nlevels
;
2424 if (level
>= nlevels
|| dn
->dn_phys
->dn_nblkptr
== 0)
2427 epbs
= dn
->dn_phys
->dn_indblkshift
- SPA_BLKPTRSHIFT
;
2428 if (dn
->dn_phys
->dn_maxblkid
< blkid
<< (epbs
* level
))
2431 dmu_buf_impl_t
*db
= dbuf_find(dn
->dn_objset
, dn
->dn_object
,
2434 mutex_exit(&db
->db_mtx
);
2436 * This dbuf already exists. It is either CACHED, or
2437 * (we assume) about to be read or filled.
2443 * Find the closest ancestor (indirect block) of the target block
2444 * that is present in the cache. In this indirect block, we will
2445 * find the bp that is at curlevel, curblkid.
2449 while (curlevel
< nlevels
- 1) {
2450 int parent_level
= curlevel
+ 1;
2451 uint64_t parent_blkid
= curblkid
>> epbs
;
2454 if (dbuf_hold_impl(dn
, parent_level
, parent_blkid
,
2455 FALSE
, TRUE
, FTAG
, &db
) == 0) {
2456 blkptr_t
*bpp
= db
->db_buf
->b_data
;
2457 bp
= bpp
[P2PHASE(curblkid
, 1 << epbs
)];
2458 dbuf_rele(db
, FTAG
);
2462 curlevel
= parent_level
;
2463 curblkid
= parent_blkid
;
2466 if (curlevel
== nlevels
- 1) {
2467 /* No cached indirect blocks found. */
2468 ASSERT3U(curblkid
, <, dn
->dn_phys
->dn_nblkptr
);
2469 bp
= dn
->dn_phys
->dn_blkptr
[curblkid
];
2471 if (BP_IS_HOLE(&bp
))
2474 ASSERT3U(curlevel
, ==, BP_GET_LEVEL(&bp
));
2476 zio_t
*pio
= zio_root(dmu_objset_spa(dn
->dn_objset
), NULL
, NULL
,
2479 dbuf_prefetch_arg_t
*dpa
= kmem_zalloc(sizeof (*dpa
), KM_SLEEP
);
2480 dsl_dataset_t
*ds
= dn
->dn_objset
->os_dsl_dataset
;
2481 SET_BOOKMARK(&dpa
->dpa_zb
, ds
!= NULL
? ds
->ds_object
: DMU_META_OBJSET
,
2482 dn
->dn_object
, level
, blkid
);
2483 dpa
->dpa_curlevel
= curlevel
;
2484 dpa
->dpa_prio
= prio
;
2485 dpa
->dpa_aflags
= aflags
;
2486 dpa
->dpa_spa
= dn
->dn_objset
->os_spa
;
2487 dpa
->dpa_dnode
= dn
;
2488 dpa
->dpa_epbs
= epbs
;
2491 /* flag if L2ARC eligible, l2arc_noprefetch then decides */
2492 if (DNODE_LEVEL_IS_L2CACHEABLE(dn
, level
))
2493 dpa
->dpa_aflags
|= ARC_FLAG_L2CACHE
;
2496 * If we have the indirect just above us, no need to do the asynchronous
2497 * prefetch chain; we'll just run the last step ourselves. If we're at
2498 * a higher level, though, we want to issue the prefetches for all the
2499 * indirect blocks asynchronously, so we can go on with whatever we were
2502 if (curlevel
== level
) {
2503 ASSERT3U(curblkid
, ==, blkid
);
2504 dbuf_issue_final_prefetch(dpa
, &bp
);
2505 kmem_free(dpa
, sizeof (*dpa
));
2507 arc_flags_t iter_aflags
= ARC_FLAG_NOWAIT
;
2508 zbookmark_phys_t zb
;
2510 /* flag if L2ARC eligible, l2arc_noprefetch then decides */
2511 if (DNODE_LEVEL_IS_L2CACHEABLE(dn
, level
))
2512 iter_aflags
|= ARC_FLAG_L2CACHE
;
2514 SET_BOOKMARK(&zb
, ds
!= NULL
? ds
->ds_object
: DMU_META_OBJSET
,
2515 dn
->dn_object
, curlevel
, curblkid
);
2516 (void) arc_read(dpa
->dpa_zio
, dpa
->dpa_spa
,
2517 &bp
, dbuf_prefetch_indirect_done
, dpa
, prio
,
2518 ZIO_FLAG_CANFAIL
| ZIO_FLAG_SPECULATIVE
,
2522 * We use pio here instead of dpa_zio since it's possible that
2523 * dpa may have already been freed.
2529 * Returns with db_holds incremented, and db_mtx not held.
2530 * Note: dn_struct_rwlock must be held.
2533 dbuf_hold_impl(dnode_t
*dn
, uint8_t level
, uint64_t blkid
,
2534 boolean_t fail_sparse
, boolean_t fail_uncached
,
2535 void *tag
, dmu_buf_impl_t
**dbp
)
2537 dmu_buf_impl_t
*db
, *parent
= NULL
;
2539 ASSERT(blkid
!= DMU_BONUS_BLKID
);
2540 ASSERT(RW_LOCK_HELD(&dn
->dn_struct_rwlock
));
2541 ASSERT3U(dn
->dn_nlevels
, >, level
);
2545 /* dbuf_find() returns with db_mtx held */
2546 db
= dbuf_find(dn
->dn_objset
, dn
->dn_object
, level
, blkid
);
2549 blkptr_t
*bp
= NULL
;
2553 return (SET_ERROR(ENOENT
));
2555 ASSERT3P(parent
, ==, NULL
);
2556 err
= dbuf_findbp(dn
, level
, blkid
, fail_sparse
, &parent
, &bp
);
2558 if (err
== 0 && bp
&& BP_IS_HOLE(bp
))
2559 err
= SET_ERROR(ENOENT
);
2562 dbuf_rele(parent
, NULL
);
2566 if (err
&& err
!= ENOENT
)
2568 db
= dbuf_create(dn
, level
, blkid
, parent
, bp
);
2571 if (fail_uncached
&& db
->db_state
!= DB_CACHED
) {
2572 mutex_exit(&db
->db_mtx
);
2573 return (SET_ERROR(ENOENT
));
2576 if (db
->db_buf
!= NULL
)
2577 ASSERT3P(db
->db
.db_data
, ==, db
->db_buf
->b_data
);
2579 ASSERT(db
->db_buf
== NULL
|| arc_referenced(db
->db_buf
));
2582 * If this buffer is currently syncing out, and we are are
2583 * still referencing it from db_data, we need to make a copy
2584 * of it in case we decide we want to dirty it again in this txg.
2586 if (db
->db_level
== 0 && db
->db_blkid
!= DMU_BONUS_BLKID
&&
2587 dn
->dn_object
!= DMU_META_DNODE_OBJECT
&&
2588 db
->db_state
== DB_CACHED
&& db
->db_data_pending
) {
2589 dbuf_dirty_record_t
*dr
= db
->db_data_pending
;
2591 if (dr
->dt
.dl
.dr_data
== db
->db_buf
) {
2592 arc_buf_contents_t type
= DBUF_GET_BUFC_TYPE(db
);
2595 arc_alloc_buf(dn
->dn_objset
->os_spa
, db
, type
,
2597 bcopy(dr
->dt
.dl
.dr_data
->b_data
, db
->db
.db_data
,
2602 if (multilist_link_active(&db
->db_cache_link
)) {
2603 ASSERT(refcount_is_zero(&db
->db_holds
));
2604 multilist_remove(dbuf_cache
, db
);
2605 (void) refcount_remove_many(&dbuf_cache_size
,
2606 db
->db
.db_size
, db
);
2608 (void) refcount_add(&db
->db_holds
, tag
);
2610 mutex_exit(&db
->db_mtx
);
2612 /* NOTE: we can't rele the parent until after we drop the db_mtx */
2614 dbuf_rele(parent
, NULL
);
2616 ASSERT3P(DB_DNODE(db
), ==, dn
);
2617 ASSERT3U(db
->db_blkid
, ==, blkid
);
2618 ASSERT3U(db
->db_level
, ==, level
);
2625 dbuf_hold(dnode_t
*dn
, uint64_t blkid
, void *tag
)
2627 return (dbuf_hold_level(dn
, 0, blkid
, tag
));
2631 dbuf_hold_level(dnode_t
*dn
, int level
, uint64_t blkid
, void *tag
)
2634 int err
= dbuf_hold_impl(dn
, level
, blkid
, FALSE
, FALSE
, tag
, &db
);
2635 return (err
? NULL
: db
);
2639 dbuf_create_bonus(dnode_t
*dn
)
2641 ASSERT(RW_WRITE_HELD(&dn
->dn_struct_rwlock
));
2643 ASSERT(dn
->dn_bonus
== NULL
);
2644 dn
->dn_bonus
= dbuf_create(dn
, 0, DMU_BONUS_BLKID
, dn
->dn_dbuf
, NULL
);
2648 dbuf_spill_set_blksz(dmu_buf_t
*db_fake
, uint64_t blksz
, dmu_tx_t
*tx
)
2650 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)db_fake
;
2653 if (db
->db_blkid
!= DMU_SPILL_BLKID
)
2654 return (SET_ERROR(ENOTSUP
));
2656 blksz
= SPA_MINBLOCKSIZE
;
2657 ASSERT3U(blksz
, <=, spa_maxblocksize(dmu_objset_spa(db
->db_objset
)));
2658 blksz
= P2ROUNDUP(blksz
, SPA_MINBLOCKSIZE
);
2662 rw_enter(&dn
->dn_struct_rwlock
, RW_WRITER
);
2663 dbuf_new_size(db
, blksz
, tx
);
2664 rw_exit(&dn
->dn_struct_rwlock
);
2671 dbuf_rm_spill(dnode_t
*dn
, dmu_tx_t
*tx
)
2673 dbuf_free_range(dn
, DMU_SPILL_BLKID
, DMU_SPILL_BLKID
, tx
);
2676 #pragma weak dmu_buf_add_ref = dbuf_add_ref
2678 dbuf_add_ref(dmu_buf_impl_t
*db
, void *tag
)
2680 int64_t holds
= refcount_add(&db
->db_holds
, tag
);
2681 ASSERT3S(holds
, >, 1);
2684 #pragma weak dmu_buf_try_add_ref = dbuf_try_add_ref
2686 dbuf_try_add_ref(dmu_buf_t
*db_fake
, objset_t
*os
, uint64_t obj
, uint64_t blkid
,
2689 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)db_fake
;
2690 dmu_buf_impl_t
*found_db
;
2691 boolean_t result
= B_FALSE
;
2693 if (db
->db_blkid
== DMU_BONUS_BLKID
)
2694 found_db
= dbuf_find_bonus(os
, obj
);
2696 found_db
= dbuf_find(os
, obj
, 0, blkid
);
2698 if (found_db
!= NULL
) {
2699 if (db
== found_db
&& dbuf_refcount(db
) > db
->db_dirtycnt
) {
2700 (void) refcount_add(&db
->db_holds
, tag
);
2703 mutex_exit(&db
->db_mtx
);
2709 * If you call dbuf_rele() you had better not be referencing the dnode handle
2710 * unless you have some other direct or indirect hold on the dnode. (An indirect
2711 * hold is a hold on one of the dnode's dbufs, including the bonus buffer.)
2712 * Without that, the dbuf_rele() could lead to a dnode_rele() followed by the
2713 * dnode's parent dbuf evicting its dnode handles.
2716 dbuf_rele(dmu_buf_impl_t
*db
, void *tag
)
2718 mutex_enter(&db
->db_mtx
);
2719 dbuf_rele_and_unlock(db
, tag
);
2723 dmu_buf_rele(dmu_buf_t
*db
, void *tag
)
2725 dbuf_rele((dmu_buf_impl_t
*)db
, tag
);
2729 * dbuf_rele() for an already-locked dbuf. This is necessary to allow
2730 * db_dirtycnt and db_holds to be updated atomically.
2733 dbuf_rele_and_unlock(dmu_buf_impl_t
*db
, void *tag
)
2737 ASSERT(MUTEX_HELD(&db
->db_mtx
));
2741 * Remove the reference to the dbuf before removing its hold on the
2742 * dnode so we can guarantee in dnode_move() that a referenced bonus
2743 * buffer has a corresponding dnode hold.
2745 holds
= refcount_remove(&db
->db_holds
, tag
);
2749 * We can't freeze indirects if there is a possibility that they
2750 * may be modified in the current syncing context.
2752 if (db
->db_buf
!= NULL
&&
2753 holds
== (db
->db_level
== 0 ? db
->db_dirtycnt
: 0)) {
2754 arc_buf_freeze(db
->db_buf
);
2757 if (holds
== db
->db_dirtycnt
&&
2758 db
->db_level
== 0 && db
->db_user_immediate_evict
)
2759 dbuf_evict_user(db
);
2762 if (db
->db_blkid
== DMU_BONUS_BLKID
) {
2764 boolean_t evict_dbuf
= db
->db_pending_evict
;
2767 * If the dnode moves here, we cannot cross this
2768 * barrier until the move completes.
2773 atomic_dec_32(&dn
->dn_dbufs_count
);
2776 * Decrementing the dbuf count means that the bonus
2777 * buffer's dnode hold is no longer discounted in
2778 * dnode_move(). The dnode cannot move until after
2779 * the dnode_rele() below.
2784 * Do not reference db after its lock is dropped.
2785 * Another thread may evict it.
2787 mutex_exit(&db
->db_mtx
);
2790 dnode_evict_bonus(dn
);
2793 } else if (db
->db_buf
== NULL
) {
2795 * This is a special case: we never associated this
2796 * dbuf with any data allocated from the ARC.
2798 ASSERT(db
->db_state
== DB_UNCACHED
||
2799 db
->db_state
== DB_NOFILL
);
2801 } else if (arc_released(db
->db_buf
)) {
2803 * This dbuf has anonymous data associated with it.
2807 boolean_t do_arc_evict
= B_FALSE
;
2809 spa_t
*spa
= dmu_objset_spa(db
->db_objset
);
2811 if (!DBUF_IS_CACHEABLE(db
) &&
2812 db
->db_blkptr
!= NULL
&&
2813 !BP_IS_HOLE(db
->db_blkptr
) &&
2814 !BP_IS_EMBEDDED(db
->db_blkptr
)) {
2815 do_arc_evict
= B_TRUE
;
2816 bp
= *db
->db_blkptr
;
2819 if (!DBUF_IS_CACHEABLE(db
) ||
2820 db
->db_pending_evict
) {
2822 } else if (!multilist_link_active(&db
->db_cache_link
)) {
2823 multilist_insert(dbuf_cache
, db
);
2824 (void) refcount_add_many(&dbuf_cache_size
,
2825 db
->db
.db_size
, db
);
2826 mutex_exit(&db
->db_mtx
);
2828 dbuf_evict_notify();
2832 arc_freed(spa
, &bp
);
2835 mutex_exit(&db
->db_mtx
);
2840 #pragma weak dmu_buf_refcount = dbuf_refcount
2842 dbuf_refcount(dmu_buf_impl_t
*db
)
2844 return (refcount_count(&db
->db_holds
));
2848 dmu_buf_replace_user(dmu_buf_t
*db_fake
, dmu_buf_user_t
*old_user
,
2849 dmu_buf_user_t
*new_user
)
2851 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)db_fake
;
2853 mutex_enter(&db
->db_mtx
);
2854 dbuf_verify_user(db
, DBVU_NOT_EVICTING
);
2855 if (db
->db_user
== old_user
)
2856 db
->db_user
= new_user
;
2858 old_user
= db
->db_user
;
2859 dbuf_verify_user(db
, DBVU_NOT_EVICTING
);
2860 mutex_exit(&db
->db_mtx
);
2866 dmu_buf_set_user(dmu_buf_t
*db_fake
, dmu_buf_user_t
*user
)
2868 return (dmu_buf_replace_user(db_fake
, NULL
, user
));
2872 dmu_buf_set_user_ie(dmu_buf_t
*db_fake
, dmu_buf_user_t
*user
)
2874 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)db_fake
;
2876 db
->db_user_immediate_evict
= TRUE
;
2877 return (dmu_buf_set_user(db_fake
, user
));
2881 dmu_buf_remove_user(dmu_buf_t
*db_fake
, dmu_buf_user_t
*user
)
2883 return (dmu_buf_replace_user(db_fake
, user
, NULL
));
2887 dmu_buf_get_user(dmu_buf_t
*db_fake
)
2889 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)db_fake
;
2891 dbuf_verify_user(db
, DBVU_NOT_EVICTING
);
2892 return (db
->db_user
);
2896 dmu_buf_user_evict_wait()
2898 taskq_wait(dbu_evict_taskq
);
2902 dmu_buf_get_blkptr(dmu_buf_t
*db
)
2904 dmu_buf_impl_t
*dbi
= (dmu_buf_impl_t
*)db
;
2905 return (dbi
->db_blkptr
);
2909 dmu_buf_get_objset(dmu_buf_t
*db
)
2911 dmu_buf_impl_t
*dbi
= (dmu_buf_impl_t
*)db
;
2912 return (dbi
->db_objset
);
2916 dmu_buf_dnode_enter(dmu_buf_t
*db
)
2918 dmu_buf_impl_t
*dbi
= (dmu_buf_impl_t
*)db
;
2919 DB_DNODE_ENTER(dbi
);
2920 return (DB_DNODE(dbi
));
2924 dmu_buf_dnode_exit(dmu_buf_t
*db
)
2926 dmu_buf_impl_t
*dbi
= (dmu_buf_impl_t
*)db
;
2931 dbuf_check_blkptr(dnode_t
*dn
, dmu_buf_impl_t
*db
)
2933 /* ASSERT(dmu_tx_is_syncing(tx) */
2934 ASSERT(MUTEX_HELD(&db
->db_mtx
));
2936 if (db
->db_blkptr
!= NULL
)
2939 if (db
->db_blkid
== DMU_SPILL_BLKID
) {
2940 db
->db_blkptr
= &dn
->dn_phys
->dn_spill
;
2941 BP_ZERO(db
->db_blkptr
);
2944 if (db
->db_level
== dn
->dn_phys
->dn_nlevels
-1) {
2946 * This buffer was allocated at a time when there was
2947 * no available blkptrs from the dnode, or it was
2948 * inappropriate to hook it in (i.e., nlevels mis-match).
2950 ASSERT(db
->db_blkid
< dn
->dn_phys
->dn_nblkptr
);
2951 ASSERT(db
->db_parent
== NULL
);
2952 db
->db_parent
= dn
->dn_dbuf
;
2953 db
->db_blkptr
= &dn
->dn_phys
->dn_blkptr
[db
->db_blkid
];
2956 dmu_buf_impl_t
*parent
= db
->db_parent
;
2957 int epbs
= dn
->dn_phys
->dn_indblkshift
- SPA_BLKPTRSHIFT
;
2959 ASSERT(dn
->dn_phys
->dn_nlevels
> 1);
2960 if (parent
== NULL
) {
2961 mutex_exit(&db
->db_mtx
);
2962 rw_enter(&dn
->dn_struct_rwlock
, RW_READER
);
2963 parent
= dbuf_hold_level(dn
, db
->db_level
+ 1,
2964 db
->db_blkid
>> epbs
, db
);
2965 rw_exit(&dn
->dn_struct_rwlock
);
2966 mutex_enter(&db
->db_mtx
);
2967 db
->db_parent
= parent
;
2969 db
->db_blkptr
= (blkptr_t
*)parent
->db
.db_data
+
2970 (db
->db_blkid
& ((1ULL << epbs
) - 1));
2976 dbuf_sync_indirect(dbuf_dirty_record_t
*dr
, dmu_tx_t
*tx
)
2978 dmu_buf_impl_t
*db
= dr
->dr_dbuf
;
2982 ASSERT(dmu_tx_is_syncing(tx
));
2984 dprintf_dbuf_bp(db
, db
->db_blkptr
, "blkptr=%p", db
->db_blkptr
);
2986 mutex_enter(&db
->db_mtx
);
2988 ASSERT(db
->db_level
> 0);
2991 /* Read the block if it hasn't been read yet. */
2992 if (db
->db_buf
== NULL
) {
2993 mutex_exit(&db
->db_mtx
);
2994 (void) dbuf_read(db
, NULL
, DB_RF_MUST_SUCCEED
);
2995 mutex_enter(&db
->db_mtx
);
2997 ASSERT3U(db
->db_state
, ==, DB_CACHED
);
2998 ASSERT(db
->db_buf
!= NULL
);
3002 /* Indirect block size must match what the dnode thinks it is. */
3003 ASSERT3U(db
->db
.db_size
, ==, 1<<dn
->dn_phys
->dn_indblkshift
);
3004 dbuf_check_blkptr(dn
, db
);
3007 /* Provide the pending dirty record to child dbufs */
3008 db
->db_data_pending
= dr
;
3010 mutex_exit(&db
->db_mtx
);
3012 dbuf_write(dr
, db
->db_buf
, tx
);
3015 mutex_enter(&dr
->dt
.di
.dr_mtx
);
3016 dbuf_sync_list(&dr
->dt
.di
.dr_children
, db
->db_level
- 1, tx
);
3017 ASSERT(list_head(&dr
->dt
.di
.dr_children
) == NULL
);
3018 mutex_exit(&dr
->dt
.di
.dr_mtx
);
3023 dbuf_sync_leaf(dbuf_dirty_record_t
*dr
, dmu_tx_t
*tx
)
3025 arc_buf_t
**datap
= &dr
->dt
.dl
.dr_data
;
3026 dmu_buf_impl_t
*db
= dr
->dr_dbuf
;
3029 uint64_t txg
= tx
->tx_txg
;
3031 ASSERT(dmu_tx_is_syncing(tx
));
3033 dprintf_dbuf_bp(db
, db
->db_blkptr
, "blkptr=%p", db
->db_blkptr
);
3035 mutex_enter(&db
->db_mtx
);
3037 * To be synced, we must be dirtied. But we
3038 * might have been freed after the dirty.
3040 if (db
->db_state
== DB_UNCACHED
) {
3041 /* This buffer has been freed since it was dirtied */
3042 ASSERT(db
->db
.db_data
== NULL
);
3043 } else if (db
->db_state
== DB_FILL
) {
3044 /* This buffer was freed and is now being re-filled */
3045 ASSERT(db
->db
.db_data
!= dr
->dt
.dl
.dr_data
);
3047 ASSERT(db
->db_state
== DB_CACHED
|| db
->db_state
== DB_NOFILL
);
3054 if (db
->db_blkid
== DMU_SPILL_BLKID
) {
3055 mutex_enter(&dn
->dn_mtx
);
3056 dn
->dn_phys
->dn_flags
|= DNODE_FLAG_SPILL_BLKPTR
;
3057 mutex_exit(&dn
->dn_mtx
);
3061 * If this is a bonus buffer, simply copy the bonus data into the
3062 * dnode. It will be written out when the dnode is synced (and it
3063 * will be synced, since it must have been dirty for dbuf_sync to
3066 if (db
->db_blkid
== DMU_BONUS_BLKID
) {
3067 dbuf_dirty_record_t
**drp
;
3069 ASSERT(*datap
!= NULL
);
3070 ASSERT0(db
->db_level
);
3071 ASSERT3U(dn
->dn_phys
->dn_bonuslen
, <=, DN_MAX_BONUSLEN
);
3072 bcopy(*datap
, DN_BONUS(dn
->dn_phys
), dn
->dn_phys
->dn_bonuslen
);
3075 if (*datap
!= db
->db
.db_data
) {
3076 zio_buf_free(*datap
, DN_MAX_BONUSLEN
);
3077 arc_space_return(DN_MAX_BONUSLEN
, ARC_SPACE_OTHER
);
3079 db
->db_data_pending
= NULL
;
3080 drp
= &db
->db_last_dirty
;
3082 drp
= &(*drp
)->dr_next
;
3083 ASSERT(dr
->dr_next
== NULL
);
3084 ASSERT(dr
->dr_dbuf
== db
);
3086 kmem_free(dr
, sizeof (dbuf_dirty_record_t
));
3087 ASSERT(db
->db_dirtycnt
> 0);
3088 db
->db_dirtycnt
-= 1;
3089 dbuf_rele_and_unlock(db
, (void *)(uintptr_t)txg
);
3096 * This function may have dropped the db_mtx lock allowing a dmu_sync
3097 * operation to sneak in. As a result, we need to ensure that we
3098 * don't check the dr_override_state until we have returned from
3099 * dbuf_check_blkptr.
3101 dbuf_check_blkptr(dn
, db
);
3104 * If this buffer is in the middle of an immediate write,
3105 * wait for the synchronous IO to complete.
3107 while (dr
->dt
.dl
.dr_override_state
== DR_IN_DMU_SYNC
) {
3108 ASSERT(dn
->dn_object
!= DMU_META_DNODE_OBJECT
);
3109 cv_wait(&db
->db_changed
, &db
->db_mtx
);
3110 ASSERT(dr
->dt
.dl
.dr_override_state
!= DR_NOT_OVERRIDDEN
);
3113 if (db
->db_state
!= DB_NOFILL
&&
3114 dn
->dn_object
!= DMU_META_DNODE_OBJECT
&&
3115 refcount_count(&db
->db_holds
) > 1 &&
3116 dr
->dt
.dl
.dr_override_state
!= DR_OVERRIDDEN
&&
3117 *datap
== db
->db_buf
) {
3119 * If this buffer is currently "in use" (i.e., there
3120 * are active holds and db_data still references it),
3121 * then make a copy before we start the write so that
3122 * any modifications from the open txg will not leak
3125 * NOTE: this copy does not need to be made for
3126 * objects only modified in the syncing context (e.g.
3127 * DNONE_DNODE blocks).
3129 int psize
= arc_buf_size(*datap
);
3130 arc_buf_contents_t type
= DBUF_GET_BUFC_TYPE(db
);
3131 enum zio_compress compress_type
= arc_get_compression(*datap
);
3133 if (compress_type
== ZIO_COMPRESS_OFF
) {
3134 *datap
= arc_alloc_buf(os
->os_spa
, db
, type
, psize
);
3136 ASSERT3U(type
, ==, ARC_BUFC_DATA
);
3137 int lsize
= arc_buf_lsize(*datap
);
3138 *datap
= arc_alloc_compressed_buf(os
->os_spa
, db
,
3139 psize
, lsize
, compress_type
);
3141 bcopy(db
->db
.db_data
, (*datap
)->b_data
, psize
);
3143 db
->db_data_pending
= dr
;
3145 mutex_exit(&db
->db_mtx
);
3147 dbuf_write(dr
, *datap
, tx
);
3149 ASSERT(!list_link_active(&dr
->dr_dirty_node
));
3150 if (dn
->dn_object
== DMU_META_DNODE_OBJECT
) {
3151 list_insert_tail(&dn
->dn_dirty_records
[txg
&TXG_MASK
], dr
);
3155 * Although zio_nowait() does not "wait for an IO", it does
3156 * initiate the IO. If this is an empty write it seems plausible
3157 * that the IO could actually be completed before the nowait
3158 * returns. We need to DB_DNODE_EXIT() first in case
3159 * zio_nowait() invalidates the dbuf.
3162 zio_nowait(dr
->dr_zio
);
3167 dbuf_sync_list(list_t
*list
, int level
, dmu_tx_t
*tx
)
3169 dbuf_dirty_record_t
*dr
;
3171 while (dr
= list_head(list
)) {
3172 if (dr
->dr_zio
!= NULL
) {
3174 * If we find an already initialized zio then we
3175 * are processing the meta-dnode, and we have finished.
3176 * The dbufs for all dnodes are put back on the list
3177 * during processing, so that we can zio_wait()
3178 * these IOs after initiating all child IOs.
3180 ASSERT3U(dr
->dr_dbuf
->db
.db_object
, ==,
3181 DMU_META_DNODE_OBJECT
);
3184 if (dr
->dr_dbuf
->db_blkid
!= DMU_BONUS_BLKID
&&
3185 dr
->dr_dbuf
->db_blkid
!= DMU_SPILL_BLKID
) {
3186 VERIFY3U(dr
->dr_dbuf
->db_level
, ==, level
);
3188 list_remove(list
, dr
);
3189 if (dr
->dr_dbuf
->db_level
> 0)
3190 dbuf_sync_indirect(dr
, tx
);
3192 dbuf_sync_leaf(dr
, tx
);
3198 dbuf_write_ready(zio_t
*zio
, arc_buf_t
*buf
, void *vdb
)
3200 dmu_buf_impl_t
*db
= vdb
;
3202 blkptr_t
*bp
= zio
->io_bp
;
3203 blkptr_t
*bp_orig
= &zio
->io_bp_orig
;
3204 spa_t
*spa
= zio
->io_spa
;
3209 ASSERT3P(db
->db_blkptr
, !=, NULL
);
3210 ASSERT3P(&db
->db_data_pending
->dr_bp_copy
, ==, bp
);
3214 delta
= bp_get_dsize_sync(spa
, bp
) - bp_get_dsize_sync(spa
, bp_orig
);
3215 dnode_diduse_space(dn
, delta
- zio
->io_prev_space_delta
);
3216 zio
->io_prev_space_delta
= delta
;
3218 if (bp
->blk_birth
!= 0) {
3219 ASSERT((db
->db_blkid
!= DMU_SPILL_BLKID
&&
3220 BP_GET_TYPE(bp
) == dn
->dn_type
) ||
3221 (db
->db_blkid
== DMU_SPILL_BLKID
&&
3222 BP_GET_TYPE(bp
) == dn
->dn_bonustype
) ||
3223 BP_IS_EMBEDDED(bp
));
3224 ASSERT(BP_GET_LEVEL(bp
) == db
->db_level
);
3227 mutex_enter(&db
->db_mtx
);
3230 if (db
->db_blkid
== DMU_SPILL_BLKID
) {
3231 ASSERT(dn
->dn_phys
->dn_flags
& DNODE_FLAG_SPILL_BLKPTR
);
3232 ASSERT(!(BP_IS_HOLE(bp
)) &&
3233 db
->db_blkptr
== &dn
->dn_phys
->dn_spill
);
3237 if (db
->db_level
== 0) {
3238 mutex_enter(&dn
->dn_mtx
);
3239 if (db
->db_blkid
> dn
->dn_phys
->dn_maxblkid
&&
3240 db
->db_blkid
!= DMU_SPILL_BLKID
)
3241 dn
->dn_phys
->dn_maxblkid
= db
->db_blkid
;
3242 mutex_exit(&dn
->dn_mtx
);
3244 if (dn
->dn_type
== DMU_OT_DNODE
) {
3245 dnode_phys_t
*dnp
= db
->db
.db_data
;
3246 for (i
= db
->db
.db_size
>> DNODE_SHIFT
; i
> 0;
3248 if (dnp
->dn_type
!= DMU_OT_NONE
)
3252 if (BP_IS_HOLE(bp
)) {
3259 blkptr_t
*ibp
= db
->db
.db_data
;
3260 ASSERT3U(db
->db
.db_size
, ==, 1<<dn
->dn_phys
->dn_indblkshift
);
3261 for (i
= db
->db
.db_size
>> SPA_BLKPTRSHIFT
; i
> 0; i
--, ibp
++) {
3262 if (BP_IS_HOLE(ibp
))
3264 fill
+= BP_GET_FILL(ibp
);
3269 if (!BP_IS_EMBEDDED(bp
))
3270 bp
->blk_fill
= fill
;
3272 mutex_exit(&db
->db_mtx
);
3274 rw_enter(&dn
->dn_struct_rwlock
, RW_WRITER
);
3275 *db
->db_blkptr
= *bp
;
3276 rw_exit(&dn
->dn_struct_rwlock
);
3281 * This function gets called just prior to running through the compression
3282 * stage of the zio pipeline. If we're an indirect block comprised of only
3283 * holes, then we want this indirect to be compressed away to a hole. In
3284 * order to do that we must zero out any information about the holes that
3285 * this indirect points to prior to before we try to compress it.
3288 dbuf_write_children_ready(zio_t
*zio
, arc_buf_t
*buf
, void *vdb
)
3290 dmu_buf_impl_t
*db
= vdb
;
3293 unsigned int epbs
, i
;
3295 ASSERT3U(db
->db_level
, >, 0);
3298 epbs
= dn
->dn_phys
->dn_indblkshift
- SPA_BLKPTRSHIFT
;
3299 ASSERT3U(epbs
, <, 31);
3301 /* Determine if all our children are holes */
3302 for (i
= 0, bp
= db
->db
.db_data
; i
< 1 << epbs
; i
++, bp
++) {
3303 if (!BP_IS_HOLE(bp
))
3308 * If all the children are holes, then zero them all out so that
3309 * we may get compressed away.
3311 if (i
== 1 << epbs
) {
3313 * We only found holes. Grab the rwlock to prevent
3314 * anybody from reading the blocks we're about to
3317 rw_enter(&dn
->dn_struct_rwlock
, RW_WRITER
);
3318 bzero(db
->db
.db_data
, db
->db
.db_size
);
3319 rw_exit(&dn
->dn_struct_rwlock
);
3325 * The SPA will call this callback several times for each zio - once
3326 * for every physical child i/o (zio->io_phys_children times). This
3327 * allows the DMU to monitor the progress of each logical i/o. For example,
3328 * there may be 2 copies of an indirect block, or many fragments of a RAID-Z
3329 * block. There may be a long delay before all copies/fragments are completed,
3330 * so this callback allows us to retire dirty space gradually, as the physical
3335 dbuf_write_physdone(zio_t
*zio
, arc_buf_t
*buf
, void *arg
)
3337 dmu_buf_impl_t
*db
= arg
;
3338 objset_t
*os
= db
->db_objset
;
3339 dsl_pool_t
*dp
= dmu_objset_pool(os
);
3340 dbuf_dirty_record_t
*dr
;
3343 dr
= db
->db_data_pending
;
3344 ASSERT3U(dr
->dr_txg
, ==, zio
->io_txg
);
3347 * The callback will be called io_phys_children times. Retire one
3348 * portion of our dirty space each time we are called. Any rounding
3349 * error will be cleaned up by dsl_pool_sync()'s call to
3350 * dsl_pool_undirty_space().
3352 delta
= dr
->dr_accounted
/ zio
->io_phys_children
;
3353 dsl_pool_undirty_space(dp
, delta
, zio
->io_txg
);
3358 dbuf_write_done(zio_t
*zio
, arc_buf_t
*buf
, void *vdb
)
3360 dmu_buf_impl_t
*db
= vdb
;
3361 blkptr_t
*bp_orig
= &zio
->io_bp_orig
;
3362 blkptr_t
*bp
= db
->db_blkptr
;
3363 objset_t
*os
= db
->db_objset
;
3364 dmu_tx_t
*tx
= os
->os_synctx
;
3365 dbuf_dirty_record_t
**drp
, *dr
;
3367 ASSERT0(zio
->io_error
);
3368 ASSERT(db
->db_blkptr
== bp
);
3371 * For nopwrites and rewrites we ensure that the bp matches our
3372 * original and bypass all the accounting.
3374 if (zio
->io_flags
& (ZIO_FLAG_IO_REWRITE
| ZIO_FLAG_NOPWRITE
)) {
3375 ASSERT(BP_EQUAL(bp
, bp_orig
));
3377 dsl_dataset_t
*ds
= os
->os_dsl_dataset
;
3378 (void) dsl_dataset_block_kill(ds
, bp_orig
, tx
, B_TRUE
);
3379 dsl_dataset_block_born(ds
, bp
, tx
);
3382 mutex_enter(&db
->db_mtx
);
3386 drp
= &db
->db_last_dirty
;
3387 while ((dr
= *drp
) != db
->db_data_pending
)
3389 ASSERT(!list_link_active(&dr
->dr_dirty_node
));
3390 ASSERT(dr
->dr_dbuf
== db
);
3391 ASSERT(dr
->dr_next
== NULL
);
3395 if (db
->db_blkid
== DMU_SPILL_BLKID
) {
3400 ASSERT(dn
->dn_phys
->dn_flags
& DNODE_FLAG_SPILL_BLKPTR
);
3401 ASSERT(!(BP_IS_HOLE(db
->db_blkptr
)) &&
3402 db
->db_blkptr
== &dn
->dn_phys
->dn_spill
);
3407 if (db
->db_level
== 0) {
3408 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
3409 ASSERT(dr
->dt
.dl
.dr_override_state
== DR_NOT_OVERRIDDEN
);
3410 if (db
->db_state
!= DB_NOFILL
) {
3411 if (dr
->dt
.dl
.dr_data
!= db
->db_buf
)
3412 arc_buf_destroy(dr
->dt
.dl
.dr_data
, db
);
3419 ASSERT(list_head(&dr
->dt
.di
.dr_children
) == NULL
);
3420 ASSERT3U(db
->db
.db_size
, ==, 1 << dn
->dn_phys
->dn_indblkshift
);
3421 if (!BP_IS_HOLE(db
->db_blkptr
)) {
3423 dn
->dn_phys
->dn_indblkshift
- SPA_BLKPTRSHIFT
;
3424 ASSERT3U(db
->db_blkid
, <=,
3425 dn
->dn_phys
->dn_maxblkid
>> (db
->db_level
* epbs
));
3426 ASSERT3U(BP_GET_LSIZE(db
->db_blkptr
), ==,
3430 mutex_destroy(&dr
->dt
.di
.dr_mtx
);
3431 list_destroy(&dr
->dt
.di
.dr_children
);
3433 kmem_free(dr
, sizeof (dbuf_dirty_record_t
));
3435 cv_broadcast(&db
->db_changed
);
3436 ASSERT(db
->db_dirtycnt
> 0);
3437 db
->db_dirtycnt
-= 1;
3438 db
->db_data_pending
= NULL
;
3439 dbuf_rele_and_unlock(db
, (void *)(uintptr_t)tx
->tx_txg
);
3443 dbuf_write_nofill_ready(zio_t
*zio
)
3445 dbuf_write_ready(zio
, NULL
, zio
->io_private
);
3449 dbuf_write_nofill_done(zio_t
*zio
)
3451 dbuf_write_done(zio
, NULL
, zio
->io_private
);
3455 dbuf_write_override_ready(zio_t
*zio
)
3457 dbuf_dirty_record_t
*dr
= zio
->io_private
;
3458 dmu_buf_impl_t
*db
= dr
->dr_dbuf
;
3460 dbuf_write_ready(zio
, NULL
, db
);
3464 dbuf_write_override_done(zio_t
*zio
)
3466 dbuf_dirty_record_t
*dr
= zio
->io_private
;
3467 dmu_buf_impl_t
*db
= dr
->dr_dbuf
;
3468 blkptr_t
*obp
= &dr
->dt
.dl
.dr_overridden_by
;
3470 mutex_enter(&db
->db_mtx
);
3471 if (!BP_EQUAL(zio
->io_bp
, obp
)) {
3472 if (!BP_IS_HOLE(obp
))
3473 dsl_free(spa_get_dsl(zio
->io_spa
), zio
->io_txg
, obp
);
3474 arc_release(dr
->dt
.dl
.dr_data
, db
);
3476 mutex_exit(&db
->db_mtx
);
3477 dbuf_write_done(zio
, NULL
, db
);
3479 if (zio
->io_abd
!= NULL
)
3480 abd_put(zio
->io_abd
);
3483 typedef struct dbuf_remap_impl_callback_arg
{
3485 uint64_t drica_blk_birth
;
3487 } dbuf_remap_impl_callback_arg_t
;
3490 dbuf_remap_impl_callback(uint64_t vdev
, uint64_t offset
, uint64_t size
,
3493 dbuf_remap_impl_callback_arg_t
*drica
= arg
;
3494 objset_t
*os
= drica
->drica_os
;
3495 spa_t
*spa
= dmu_objset_spa(os
);
3496 dmu_tx_t
*tx
= drica
->drica_tx
;
3498 ASSERT(dsl_pool_sync_context(spa_get_dsl(spa
)));
3500 if (os
== spa_meta_objset(spa
)) {
3501 spa_vdev_indirect_mark_obsolete(spa
, vdev
, offset
, size
, tx
);
3503 dsl_dataset_block_remapped(dmu_objset_ds(os
), vdev
, offset
,
3504 size
, drica
->drica_blk_birth
, tx
);
3509 dbuf_remap_impl(dnode_t
*dn
, blkptr_t
*bp
, dmu_tx_t
*tx
)
3511 blkptr_t bp_copy
= *bp
;
3512 spa_t
*spa
= dmu_objset_spa(dn
->dn_objset
);
3513 dbuf_remap_impl_callback_arg_t drica
;
3515 ASSERT(dsl_pool_sync_context(spa_get_dsl(spa
)));
3517 drica
.drica_os
= dn
->dn_objset
;
3518 drica
.drica_blk_birth
= bp
->blk_birth
;
3519 drica
.drica_tx
= tx
;
3520 if (spa_remap_blkptr(spa
, &bp_copy
, dbuf_remap_impl_callback
,
3523 * The struct_rwlock prevents dbuf_read_impl() from
3524 * dereferencing the BP while we are changing it. To
3525 * avoid lock contention, only grab it when we are actually
3528 rw_enter(&dn
->dn_struct_rwlock
, RW_WRITER
);
3530 rw_exit(&dn
->dn_struct_rwlock
);
3535 * Returns true if a dbuf_remap would modify the dbuf. We do this by attempting
3536 * to remap a copy of every bp in the dbuf.
3539 dbuf_can_remap(const dmu_buf_impl_t
*db
)
3541 spa_t
*spa
= dmu_objset_spa(db
->db_objset
);
3542 blkptr_t
*bp
= db
->db
.db_data
;
3543 boolean_t ret
= B_FALSE
;
3545 ASSERT3U(db
->db_level
, >, 0);
3546 ASSERT3S(db
->db_state
, ==, DB_CACHED
);
3548 ASSERT(spa_feature_is_active(spa
, SPA_FEATURE_DEVICE_REMOVAL
));
3550 spa_config_enter(spa
, SCL_VDEV
, FTAG
, RW_READER
);
3551 for (int i
= 0; i
< db
->db
.db_size
>> SPA_BLKPTRSHIFT
; i
++) {
3552 blkptr_t bp_copy
= bp
[i
];
3553 if (spa_remap_blkptr(spa
, &bp_copy
, NULL
, NULL
)) {
3558 spa_config_exit(spa
, SCL_VDEV
, FTAG
);
3564 dnode_needs_remap(const dnode_t
*dn
)
3566 spa_t
*spa
= dmu_objset_spa(dn
->dn_objset
);
3567 boolean_t ret
= B_FALSE
;
3569 if (dn
->dn_phys
->dn_nlevels
== 0) {
3573 ASSERT(spa_feature_is_active(spa
, SPA_FEATURE_DEVICE_REMOVAL
));
3575 spa_config_enter(spa
, SCL_VDEV
, FTAG
, RW_READER
);
3576 for (int j
= 0; j
< dn
->dn_phys
->dn_nblkptr
; j
++) {
3577 blkptr_t bp_copy
= dn
->dn_phys
->dn_blkptr
[j
];
3578 if (spa_remap_blkptr(spa
, &bp_copy
, NULL
, NULL
)) {
3583 spa_config_exit(spa
, SCL_VDEV
, FTAG
);
3589 * Remap any existing BP's to concrete vdevs, if possible.
3592 dbuf_remap(dnode_t
*dn
, dmu_buf_impl_t
*db
, dmu_tx_t
*tx
)
3594 spa_t
*spa
= dmu_objset_spa(db
->db_objset
);
3595 ASSERT(dsl_pool_sync_context(spa_get_dsl(spa
)));
3597 if (!spa_feature_is_active(spa
, SPA_FEATURE_DEVICE_REMOVAL
))
3600 if (db
->db_level
> 0) {
3601 blkptr_t
*bp
= db
->db
.db_data
;
3602 for (int i
= 0; i
< db
->db
.db_size
>> SPA_BLKPTRSHIFT
; i
++) {
3603 dbuf_remap_impl(dn
, &bp
[i
], tx
);
3605 } else if (db
->db
.db_object
== DMU_META_DNODE_OBJECT
) {
3606 dnode_phys_t
*dnp
= db
->db
.db_data
;
3607 ASSERT3U(db
->db_dnode_handle
->dnh_dnode
->dn_type
, ==,
3609 for (int i
= 0; i
< db
->db
.db_size
>> DNODE_SHIFT
; i
++) {
3610 for (int j
= 0; j
< dnp
[i
].dn_nblkptr
; j
++) {
3611 dbuf_remap_impl(dn
, &dnp
[i
].dn_blkptr
[j
], tx
);
3618 /* Issue I/O to commit a dirty buffer to disk. */
3620 dbuf_write(dbuf_dirty_record_t
*dr
, arc_buf_t
*data
, dmu_tx_t
*tx
)
3622 dmu_buf_impl_t
*db
= dr
->dr_dbuf
;
3625 dmu_buf_impl_t
*parent
= db
->db_parent
;
3626 uint64_t txg
= tx
->tx_txg
;
3627 zbookmark_phys_t zb
;
3632 ASSERT(dmu_tx_is_syncing(tx
));
3638 if (db
->db_state
!= DB_NOFILL
) {
3639 if (db
->db_level
> 0 || dn
->dn_type
== DMU_OT_DNODE
) {
3641 * Private object buffers are released here rather
3642 * than in dbuf_dirty() since they are only modified
3643 * in the syncing context and we don't want the
3644 * overhead of making multiple copies of the data.
3646 if (BP_IS_HOLE(db
->db_blkptr
)) {
3649 dbuf_release_bp(db
);
3651 dbuf_remap(dn
, db
, tx
);
3655 if (parent
!= dn
->dn_dbuf
) {
3656 /* Our parent is an indirect block. */
3657 /* We have a dirty parent that has been scheduled for write. */
3658 ASSERT(parent
&& parent
->db_data_pending
);
3659 /* Our parent's buffer is one level closer to the dnode. */
3660 ASSERT(db
->db_level
== parent
->db_level
-1);
3662 * We're about to modify our parent's db_data by modifying
3663 * our block pointer, so the parent must be released.
3665 ASSERT(arc_released(parent
->db_buf
));
3666 zio
= parent
->db_data_pending
->dr_zio
;
3668 /* Our parent is the dnode itself. */
3669 ASSERT((db
->db_level
== dn
->dn_phys
->dn_nlevels
-1 &&
3670 db
->db_blkid
!= DMU_SPILL_BLKID
) ||
3671 (db
->db_blkid
== DMU_SPILL_BLKID
&& db
->db_level
== 0));
3672 if (db
->db_blkid
!= DMU_SPILL_BLKID
)
3673 ASSERT3P(db
->db_blkptr
, ==,
3674 &dn
->dn_phys
->dn_blkptr
[db
->db_blkid
]);
3678 ASSERT(db
->db_level
== 0 || data
== db
->db_buf
);
3679 ASSERT3U(db
->db_blkptr
->blk_birth
, <=, txg
);
3682 SET_BOOKMARK(&zb
, os
->os_dsl_dataset
?
3683 os
->os_dsl_dataset
->ds_object
: DMU_META_OBJSET
,
3684 db
->db
.db_object
, db
->db_level
, db
->db_blkid
);
3686 if (db
->db_blkid
== DMU_SPILL_BLKID
)
3688 wp_flag
|= (db
->db_state
== DB_NOFILL
) ? WP_NOFILL
: 0;
3690 dmu_write_policy(os
, dn
, db
->db_level
, wp_flag
, &zp
);
3694 * We copy the blkptr now (rather than when we instantiate the dirty
3695 * record), because its value can change between open context and
3696 * syncing context. We do not need to hold dn_struct_rwlock to read
3697 * db_blkptr because we are in syncing context.
3699 dr
->dr_bp_copy
= *db
->db_blkptr
;
3701 if (db
->db_level
== 0 &&
3702 dr
->dt
.dl
.dr_override_state
== DR_OVERRIDDEN
) {
3704 * The BP for this block has been provided by open context
3705 * (by dmu_sync() or dmu_buf_write_embedded()).
3707 abd_t
*contents
= (data
!= NULL
) ?
3708 abd_get_from_buf(data
->b_data
, arc_buf_size(data
)) : NULL
;
3710 dr
->dr_zio
= zio_write(zio
, os
->os_spa
, txg
, &dr
->dr_bp_copy
,
3711 contents
, db
->db
.db_size
, db
->db
.db_size
, &zp
,
3712 dbuf_write_override_ready
, NULL
, NULL
,
3713 dbuf_write_override_done
,
3714 dr
, ZIO_PRIORITY_ASYNC_WRITE
, ZIO_FLAG_MUSTSUCCEED
, &zb
);
3715 mutex_enter(&db
->db_mtx
);
3716 dr
->dt
.dl
.dr_override_state
= DR_NOT_OVERRIDDEN
;
3717 zio_write_override(dr
->dr_zio
, &dr
->dt
.dl
.dr_overridden_by
,
3718 dr
->dt
.dl
.dr_copies
, dr
->dt
.dl
.dr_nopwrite
);
3719 mutex_exit(&db
->db_mtx
);
3720 } else if (db
->db_state
== DB_NOFILL
) {
3721 ASSERT(zp
.zp_checksum
== ZIO_CHECKSUM_OFF
||
3722 zp
.zp_checksum
== ZIO_CHECKSUM_NOPARITY
);
3723 dr
->dr_zio
= zio_write(zio
, os
->os_spa
, txg
,
3724 &dr
->dr_bp_copy
, NULL
, db
->db
.db_size
, db
->db
.db_size
, &zp
,
3725 dbuf_write_nofill_ready
, NULL
, NULL
,
3726 dbuf_write_nofill_done
, db
,
3727 ZIO_PRIORITY_ASYNC_WRITE
,
3728 ZIO_FLAG_MUSTSUCCEED
| ZIO_FLAG_NODATA
, &zb
);
3730 ASSERT(arc_released(data
));
3733 * For indirect blocks, we want to setup the children
3734 * ready callback so that we can properly handle an indirect
3735 * block that only contains holes.
3737 arc_done_func_t
*children_ready_cb
= NULL
;
3738 if (db
->db_level
!= 0)
3739 children_ready_cb
= dbuf_write_children_ready
;
3741 dr
->dr_zio
= arc_write(zio
, os
->os_spa
, txg
,
3742 &dr
->dr_bp_copy
, data
, DBUF_IS_L2CACHEABLE(db
),
3743 &zp
, dbuf_write_ready
, children_ready_cb
,
3744 dbuf_write_physdone
, dbuf_write_done
, db
,
3745 ZIO_PRIORITY_ASYNC_WRITE
, ZIO_FLAG_MUSTSUCCEED
, &zb
);