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, 2015 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.
30 #include <sys/zfs_context.h>
32 #include <sys/dmu_send.h>
33 #include <sys/dmu_impl.h>
35 #include <sys/dmu_objset.h>
36 #include <sys/dsl_dataset.h>
37 #include <sys/dsl_dir.h>
38 #include <sys/dmu_tx.h>
41 #include <sys/dmu_zfetch.h>
43 #include <sys/sa_impl.h>
44 #include <sys/zfeature.h>
45 #include <sys/blkptr.h>
46 #include <sys/range_tree.h>
49 * Number of times that zfs_free_range() took the slow path while doing
50 * a zfs receive. A nonzero value indicates a potential performance problem.
52 uint64_t zfs_free_range_recv_miss
;
54 static void dbuf_destroy(dmu_buf_impl_t
*db
);
55 static boolean_t
dbuf_undirty(dmu_buf_impl_t
*db
, dmu_tx_t
*tx
);
56 static void dbuf_write(dbuf_dirty_record_t
*dr
, arc_buf_t
*data
, dmu_tx_t
*tx
);
59 extern inline void dmu_buf_init_user(dmu_buf_user_t
*dbu
,
60 dmu_buf_evict_func_t
*evict_func
, dmu_buf_t
**clear_on_evict_dbufp
);
64 * Global data structures and functions for the dbuf cache.
66 static kmem_cache_t
*dbuf_cache
;
67 static taskq_t
*dbu_evict_taskq
;
71 dbuf_cons(void *vdb
, void *unused
, int kmflag
)
73 dmu_buf_impl_t
*db
= vdb
;
74 bzero(db
, sizeof (dmu_buf_impl_t
));
76 mutex_init(&db
->db_mtx
, NULL
, MUTEX_DEFAULT
, NULL
);
77 cv_init(&db
->db_changed
, NULL
, CV_DEFAULT
, NULL
);
78 refcount_create(&db
->db_holds
);
85 dbuf_dest(void *vdb
, void *unused
)
87 dmu_buf_impl_t
*db
= vdb
;
88 mutex_destroy(&db
->db_mtx
);
89 cv_destroy(&db
->db_changed
);
90 refcount_destroy(&db
->db_holds
);
94 * dbuf hash table routines
96 static dbuf_hash_table_t dbuf_hash_table
;
98 static uint64_t dbuf_hash_count
;
101 dbuf_hash(void *os
, uint64_t obj
, uint8_t lvl
, uint64_t blkid
)
103 uintptr_t osv
= (uintptr_t)os
;
104 uint64_t crc
= -1ULL;
106 ASSERT(zfs_crc64_table
[128] == ZFS_CRC64_POLY
);
107 crc
= (crc
>> 8) ^ zfs_crc64_table
[(crc
^ (lvl
)) & 0xFF];
108 crc
= (crc
>> 8) ^ zfs_crc64_table
[(crc
^ (osv
>> 6)) & 0xFF];
109 crc
= (crc
>> 8) ^ zfs_crc64_table
[(crc
^ (obj
>> 0)) & 0xFF];
110 crc
= (crc
>> 8) ^ zfs_crc64_table
[(crc
^ (obj
>> 8)) & 0xFF];
111 crc
= (crc
>> 8) ^ zfs_crc64_table
[(crc
^ (blkid
>> 0)) & 0xFF];
112 crc
= (crc
>> 8) ^ zfs_crc64_table
[(crc
^ (blkid
>> 8)) & 0xFF];
114 crc
^= (osv
>>14) ^ (obj
>>16) ^ (blkid
>>16);
119 #define DBUF_HASH(os, obj, level, blkid) dbuf_hash(os, obj, level, blkid);
121 #define DBUF_EQUAL(dbuf, os, obj, level, blkid) \
122 ((dbuf)->db.db_object == (obj) && \
123 (dbuf)->db_objset == (os) && \
124 (dbuf)->db_level == (level) && \
125 (dbuf)->db_blkid == (blkid))
128 dbuf_find(objset_t
*os
, uint64_t obj
, uint8_t level
, uint64_t blkid
)
130 dbuf_hash_table_t
*h
= &dbuf_hash_table
;
131 uint64_t hv
= DBUF_HASH(os
, obj
, level
, blkid
);
132 uint64_t idx
= hv
& h
->hash_table_mask
;
135 mutex_enter(DBUF_HASH_MUTEX(h
, idx
));
136 for (db
= h
->hash_table
[idx
]; db
!= NULL
; db
= db
->db_hash_next
) {
137 if (DBUF_EQUAL(db
, os
, obj
, level
, blkid
)) {
138 mutex_enter(&db
->db_mtx
);
139 if (db
->db_state
!= DB_EVICTING
) {
140 mutex_exit(DBUF_HASH_MUTEX(h
, idx
));
143 mutex_exit(&db
->db_mtx
);
146 mutex_exit(DBUF_HASH_MUTEX(h
, idx
));
150 static dmu_buf_impl_t
*
151 dbuf_find_bonus(objset_t
*os
, uint64_t object
)
154 dmu_buf_impl_t
*db
= NULL
;
156 if (dnode_hold(os
, object
, FTAG
, &dn
) == 0) {
157 rw_enter(&dn
->dn_struct_rwlock
, RW_READER
);
158 if (dn
->dn_bonus
!= NULL
) {
160 mutex_enter(&db
->db_mtx
);
162 rw_exit(&dn
->dn_struct_rwlock
);
163 dnode_rele(dn
, FTAG
);
169 * Insert an entry into the hash table. If there is already an element
170 * equal to elem in the hash table, then the already existing element
171 * will be returned and the new element will not be inserted.
172 * Otherwise returns NULL.
174 static dmu_buf_impl_t
*
175 dbuf_hash_insert(dmu_buf_impl_t
*db
)
177 dbuf_hash_table_t
*h
= &dbuf_hash_table
;
178 objset_t
*os
= db
->db_objset
;
179 uint64_t obj
= db
->db
.db_object
;
180 int level
= db
->db_level
;
181 uint64_t blkid
= db
->db_blkid
;
182 uint64_t hv
= DBUF_HASH(os
, obj
, level
, blkid
);
183 uint64_t idx
= hv
& h
->hash_table_mask
;
186 mutex_enter(DBUF_HASH_MUTEX(h
, idx
));
187 for (dbf
= h
->hash_table
[idx
]; dbf
!= NULL
; dbf
= dbf
->db_hash_next
) {
188 if (DBUF_EQUAL(dbf
, os
, obj
, level
, blkid
)) {
189 mutex_enter(&dbf
->db_mtx
);
190 if (dbf
->db_state
!= DB_EVICTING
) {
191 mutex_exit(DBUF_HASH_MUTEX(h
, idx
));
194 mutex_exit(&dbf
->db_mtx
);
198 mutex_enter(&db
->db_mtx
);
199 db
->db_hash_next
= h
->hash_table
[idx
];
200 h
->hash_table
[idx
] = db
;
201 mutex_exit(DBUF_HASH_MUTEX(h
, idx
));
202 atomic_inc_64(&dbuf_hash_count
);
208 * Remove an entry from the hash table. It must be in the EVICTING state.
211 dbuf_hash_remove(dmu_buf_impl_t
*db
)
213 dbuf_hash_table_t
*h
= &dbuf_hash_table
;
214 uint64_t hv
= DBUF_HASH(db
->db_objset
, db
->db
.db_object
,
215 db
->db_level
, db
->db_blkid
);
216 uint64_t idx
= hv
& h
->hash_table_mask
;
217 dmu_buf_impl_t
*dbf
, **dbp
;
220 * We musn't hold db_mtx to maintain lock ordering:
221 * DBUF_HASH_MUTEX > db_mtx.
223 ASSERT(refcount_is_zero(&db
->db_holds
));
224 ASSERT(db
->db_state
== DB_EVICTING
);
225 ASSERT(!MUTEX_HELD(&db
->db_mtx
));
227 mutex_enter(DBUF_HASH_MUTEX(h
, idx
));
228 dbp
= &h
->hash_table
[idx
];
229 while ((dbf
= *dbp
) != db
) {
230 dbp
= &dbf
->db_hash_next
;
233 *dbp
= db
->db_hash_next
;
234 db
->db_hash_next
= NULL
;
235 mutex_exit(DBUF_HASH_MUTEX(h
, idx
));
236 atomic_dec_64(&dbuf_hash_count
);
239 static arc_evict_func_t dbuf_do_evict
;
244 } dbvu_verify_type_t
;
247 dbuf_verify_user(dmu_buf_impl_t
*db
, dbvu_verify_type_t verify_type
)
252 if (db
->db_user
== NULL
)
255 /* Only data blocks support the attachment of user data. */
256 ASSERT(db
->db_level
== 0);
258 /* Clients must resolve a dbuf before attaching user data. */
259 ASSERT(db
->db
.db_data
!= NULL
);
260 ASSERT3U(db
->db_state
, ==, DB_CACHED
);
262 holds
= refcount_count(&db
->db_holds
);
263 if (verify_type
== DBVU_EVICTING
) {
265 * Immediate eviction occurs when holds == dirtycnt.
266 * For normal eviction buffers, holds is zero on
267 * eviction, except when dbuf_fix_old_data() calls
268 * dbuf_clear_data(). However, the hold count can grow
269 * during eviction even though db_mtx is held (see
270 * dmu_bonus_hold() for an example), so we can only
271 * test the generic invariant that holds >= dirtycnt.
273 ASSERT3U(holds
, >=, db
->db_dirtycnt
);
275 if (db
->db_immediate_evict
== TRUE
)
276 ASSERT3U(holds
, >=, db
->db_dirtycnt
);
278 ASSERT3U(holds
, >, 0);
284 dbuf_evict_user(dmu_buf_impl_t
*db
)
286 dmu_buf_user_t
*dbu
= db
->db_user
;
288 ASSERT(MUTEX_HELD(&db
->db_mtx
));
293 dbuf_verify_user(db
, DBVU_EVICTING
);
297 if (dbu
->dbu_clear_on_evict_dbufp
!= NULL
)
298 *dbu
->dbu_clear_on_evict_dbufp
= NULL
;
302 * Invoke the callback from a taskq to avoid lock order reversals
303 * and limit stack depth.
305 taskq_dispatch_ent(dbu_evict_taskq
, dbu
->dbu_evict_func
, dbu
, 0,
310 dbuf_is_metadata(dmu_buf_impl_t
*db
)
312 if (db
->db_level
> 0) {
315 boolean_t is_metadata
;
318 is_metadata
= DMU_OT_IS_METADATA(DB_DNODE(db
)->dn_type
);
321 return (is_metadata
);
326 dbuf_evict(dmu_buf_impl_t
*db
)
328 ASSERT(MUTEX_HELD(&db
->db_mtx
));
329 ASSERT(db
->db_buf
== NULL
);
330 ASSERT(db
->db_data_pending
== NULL
);
339 uint64_t hsize
= 1ULL << 16;
340 dbuf_hash_table_t
*h
= &dbuf_hash_table
;
344 * The hash table is big enough to fill all of physical memory
345 * with an average 4K block size. The table will take up
346 * totalmem*sizeof(void*)/4K (i.e. 2MB/GB with 8-byte pointers).
348 while (hsize
* 4096 < physmem
* PAGESIZE
)
352 h
->hash_table_mask
= hsize
- 1;
353 h
->hash_table
= kmem_zalloc(hsize
* sizeof (void *), KM_NOSLEEP
);
354 if (h
->hash_table
== NULL
) {
355 /* XXX - we should really return an error instead of assert */
356 ASSERT(hsize
> (1ULL << 10));
361 dbuf_cache
= kmem_cache_create("dmu_buf_impl_t",
362 sizeof (dmu_buf_impl_t
),
363 0, dbuf_cons
, dbuf_dest
, NULL
, NULL
, NULL
, 0);
365 for (i
= 0; i
< DBUF_MUTEXES
; i
++)
366 mutex_init(&h
->hash_mutexes
[i
], NULL
, MUTEX_DEFAULT
, NULL
);
369 * All entries are queued via taskq_dispatch_ent(), so min/maxalloc
370 * configuration is not required.
372 dbu_evict_taskq
= taskq_create("dbu_evict", 1, minclsyspri
, 0, 0, 0);
378 dbuf_hash_table_t
*h
= &dbuf_hash_table
;
381 for (i
= 0; i
< DBUF_MUTEXES
; i
++)
382 mutex_destroy(&h
->hash_mutexes
[i
]);
383 kmem_free(h
->hash_table
, (h
->hash_table_mask
+ 1) * sizeof (void *));
384 kmem_cache_destroy(dbuf_cache
);
385 taskq_destroy(dbu_evict_taskq
);
394 dbuf_verify(dmu_buf_impl_t
*db
)
397 dbuf_dirty_record_t
*dr
;
399 ASSERT(MUTEX_HELD(&db
->db_mtx
));
401 if (!(zfs_flags
& ZFS_DEBUG_DBUF_VERIFY
))
404 ASSERT(db
->db_objset
!= NULL
);
408 ASSERT(db
->db_parent
== NULL
);
409 ASSERT(db
->db_blkptr
== NULL
);
411 ASSERT3U(db
->db
.db_object
, ==, dn
->dn_object
);
412 ASSERT3P(db
->db_objset
, ==, dn
->dn_objset
);
413 ASSERT3U(db
->db_level
, <, dn
->dn_nlevels
);
414 ASSERT(db
->db_blkid
== DMU_BONUS_BLKID
||
415 db
->db_blkid
== DMU_SPILL_BLKID
||
416 !avl_is_empty(&dn
->dn_dbufs
));
418 if (db
->db_blkid
== DMU_BONUS_BLKID
) {
420 ASSERT3U(db
->db
.db_size
, >=, dn
->dn_bonuslen
);
421 ASSERT3U(db
->db
.db_offset
, ==, DMU_BONUS_BLKID
);
422 } else if (db
->db_blkid
== DMU_SPILL_BLKID
) {
424 ASSERT3U(db
->db
.db_size
, >=, dn
->dn_bonuslen
);
425 ASSERT0(db
->db
.db_offset
);
427 ASSERT3U(db
->db
.db_offset
, ==, db
->db_blkid
* db
->db
.db_size
);
430 for (dr
= db
->db_data_pending
; dr
!= NULL
; dr
= dr
->dr_next
)
431 ASSERT(dr
->dr_dbuf
== db
);
433 for (dr
= db
->db_last_dirty
; dr
!= NULL
; dr
= dr
->dr_next
)
434 ASSERT(dr
->dr_dbuf
== db
);
437 * We can't assert that db_size matches dn_datablksz because it
438 * can be momentarily different when another thread is doing
441 if (db
->db_level
== 0 && db
->db
.db_object
== DMU_META_DNODE_OBJECT
) {
442 dr
= db
->db_data_pending
;
444 * It should only be modified in syncing context, so
445 * make sure we only have one copy of the data.
447 ASSERT(dr
== NULL
|| dr
->dt
.dl
.dr_data
== db
->db_buf
);
450 /* verify db->db_blkptr */
452 if (db
->db_parent
== dn
->dn_dbuf
) {
453 /* db is pointed to by the dnode */
454 /* ASSERT3U(db->db_blkid, <, dn->dn_nblkptr); */
455 if (DMU_OBJECT_IS_SPECIAL(db
->db
.db_object
))
456 ASSERT(db
->db_parent
== NULL
);
458 ASSERT(db
->db_parent
!= NULL
);
459 if (db
->db_blkid
!= DMU_SPILL_BLKID
)
460 ASSERT3P(db
->db_blkptr
, ==,
461 &dn
->dn_phys
->dn_blkptr
[db
->db_blkid
]);
463 /* db is pointed to by an indirect block */
464 int epb
= db
->db_parent
->db
.db_size
>> SPA_BLKPTRSHIFT
;
465 ASSERT3U(db
->db_parent
->db_level
, ==, db
->db_level
+1);
466 ASSERT3U(db
->db_parent
->db
.db_object
, ==,
469 * dnode_grow_indblksz() can make this fail if we don't
470 * have the struct_rwlock. XXX indblksz no longer
471 * grows. safe to do this now?
473 if (RW_WRITE_HELD(&dn
->dn_struct_rwlock
)) {
474 ASSERT3P(db
->db_blkptr
, ==,
475 ((blkptr_t
*)db
->db_parent
->db
.db_data
+
476 db
->db_blkid
% epb
));
480 if ((db
->db_blkptr
== NULL
|| BP_IS_HOLE(db
->db_blkptr
)) &&
481 (db
->db_buf
== NULL
|| db
->db_buf
->b_data
) &&
482 db
->db
.db_data
&& db
->db_blkid
!= DMU_BONUS_BLKID
&&
483 db
->db_state
!= DB_FILL
&& !dn
->dn_free_txg
) {
485 * If the blkptr isn't set but they have nonzero data,
486 * it had better be dirty, otherwise we'll lose that
487 * data when we evict this buffer.
489 if (db
->db_dirtycnt
== 0) {
490 uint64_t *buf
= db
->db
.db_data
;
493 for (i
= 0; i
< db
->db
.db_size
>> 3; i
++) {
503 dbuf_clear_data(dmu_buf_impl_t
*db
)
505 ASSERT(MUTEX_HELD(&db
->db_mtx
));
508 db
->db
.db_data
= NULL
;
509 if (db
->db_state
!= DB_NOFILL
)
510 db
->db_state
= DB_UNCACHED
;
514 dbuf_set_data(dmu_buf_impl_t
*db
, arc_buf_t
*buf
)
516 ASSERT(MUTEX_HELD(&db
->db_mtx
));
520 ASSERT(buf
->b_data
!= NULL
);
521 db
->db
.db_data
= buf
->b_data
;
522 if (!arc_released(buf
))
523 arc_set_callback(buf
, dbuf_do_evict
, db
);
527 * Loan out an arc_buf for read. Return the loaned arc_buf.
530 dbuf_loan_arcbuf(dmu_buf_impl_t
*db
)
534 mutex_enter(&db
->db_mtx
);
535 if (arc_released(db
->db_buf
) || refcount_count(&db
->db_holds
) > 1) {
536 int blksz
= db
->db
.db_size
;
537 spa_t
*spa
= db
->db_objset
->os_spa
;
539 mutex_exit(&db
->db_mtx
);
540 abuf
= arc_loan_buf(spa
, blksz
);
541 bcopy(db
->db
.db_data
, abuf
->b_data
, blksz
);
544 arc_loan_inuse_buf(abuf
, db
);
546 mutex_exit(&db
->db_mtx
);
552 * Calculate which level n block references the data at the level 0 offset
556 dbuf_whichblock(dnode_t
*dn
, int64_t level
, uint64_t offset
)
558 if (dn
->dn_datablkshift
!= 0 && dn
->dn_indblkshift
!= 0) {
560 * The level n blkid is equal to the level 0 blkid divided by
561 * the number of level 0s in a level n block.
563 * The level 0 blkid is offset >> datablkshift =
564 * offset / 2^datablkshift.
566 * The number of level 0s in a level n is the number of block
567 * pointers in an indirect block, raised to the power of level.
568 * This is 2^(indblkshift - SPA_BLKPTRSHIFT)^level =
569 * 2^(level*(indblkshift - SPA_BLKPTRSHIFT)).
571 * Thus, the level n blkid is: offset /
572 * ((2^datablkshift)*(2^(level*(indblkshift - SPA_BLKPTRSHIFT)))
573 * = offset / 2^(datablkshift + level *
574 * (indblkshift - SPA_BLKPTRSHIFT))
575 * = offset >> (datablkshift + level *
576 * (indblkshift - SPA_BLKPTRSHIFT))
578 return (offset
>> (dn
->dn_datablkshift
+ level
*
579 (dn
->dn_indblkshift
- SPA_BLKPTRSHIFT
)));
581 ASSERT3U(offset
, <, dn
->dn_datablksz
);
587 dbuf_read_done(zio_t
*zio
, arc_buf_t
*buf
, void *vdb
)
589 dmu_buf_impl_t
*db
= vdb
;
591 mutex_enter(&db
->db_mtx
);
592 ASSERT3U(db
->db_state
, ==, DB_READ
);
594 * All reads are synchronous, so we must have a hold on the dbuf
596 ASSERT(refcount_count(&db
->db_holds
) > 0);
597 ASSERT(db
->db_buf
== NULL
);
598 ASSERT(db
->db
.db_data
== NULL
);
599 if (db
->db_level
== 0 && db
->db_freed_in_flight
) {
600 /* we were freed in flight; disregard any error */
601 arc_release(buf
, db
);
602 bzero(buf
->b_data
, db
->db
.db_size
);
604 db
->db_freed_in_flight
= FALSE
;
605 dbuf_set_data(db
, buf
);
606 db
->db_state
= DB_CACHED
;
607 } else if (zio
== NULL
|| zio
->io_error
== 0) {
608 dbuf_set_data(db
, buf
);
609 db
->db_state
= DB_CACHED
;
611 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
612 ASSERT3P(db
->db_buf
, ==, NULL
);
613 VERIFY(arc_buf_remove_ref(buf
, db
));
614 db
->db_state
= DB_UNCACHED
;
616 cv_broadcast(&db
->db_changed
);
617 dbuf_rele_and_unlock(db
, NULL
);
621 dbuf_read_impl(dmu_buf_impl_t
*db
, zio_t
*zio
, uint32_t *flags
)
625 arc_flags_t aflags
= ARC_FLAG_NOWAIT
;
629 ASSERT(!refcount_is_zero(&db
->db_holds
));
630 /* We need the struct_rwlock to prevent db_blkptr from changing. */
631 ASSERT(RW_LOCK_HELD(&dn
->dn_struct_rwlock
));
632 ASSERT(MUTEX_HELD(&db
->db_mtx
));
633 ASSERT(db
->db_state
== DB_UNCACHED
);
634 ASSERT(db
->db_buf
== NULL
);
636 if (db
->db_blkid
== DMU_BONUS_BLKID
) {
637 int bonuslen
= MIN(dn
->dn_bonuslen
, dn
->dn_phys
->dn_bonuslen
);
639 ASSERT3U(bonuslen
, <=, db
->db
.db_size
);
640 db
->db
.db_data
= zio_buf_alloc(DN_MAX_BONUSLEN
);
641 arc_space_consume(DN_MAX_BONUSLEN
, ARC_SPACE_OTHER
);
642 if (bonuslen
< DN_MAX_BONUSLEN
)
643 bzero(db
->db
.db_data
, DN_MAX_BONUSLEN
);
645 bcopy(DN_BONUS(dn
->dn_phys
), db
->db
.db_data
, bonuslen
);
647 db
->db_state
= DB_CACHED
;
648 mutex_exit(&db
->db_mtx
);
653 * Recheck BP_IS_HOLE() after dnode_block_freed() in case dnode_sync()
654 * processes the delete record and clears the bp while we are waiting
655 * for the dn_mtx (resulting in a "no" from block_freed).
657 if (db
->db_blkptr
== NULL
|| BP_IS_HOLE(db
->db_blkptr
) ||
658 (db
->db_level
== 0 && (dnode_block_freed(dn
, db
->db_blkid
) ||
659 BP_IS_HOLE(db
->db_blkptr
)))) {
660 arc_buf_contents_t type
= DBUF_GET_BUFC_TYPE(db
);
663 dbuf_set_data(db
, arc_buf_alloc(db
->db_objset
->os_spa
,
664 db
->db
.db_size
, db
, type
));
665 bzero(db
->db
.db_data
, db
->db
.db_size
);
666 db
->db_state
= DB_CACHED
;
667 *flags
|= DB_RF_CACHED
;
668 mutex_exit(&db
->db_mtx
);
674 db
->db_state
= DB_READ
;
675 mutex_exit(&db
->db_mtx
);
677 if (DBUF_IS_L2CACHEABLE(db
))
678 aflags
|= ARC_FLAG_L2CACHE
;
679 if (DBUF_IS_L2COMPRESSIBLE(db
))
680 aflags
|= ARC_FLAG_L2COMPRESS
;
682 SET_BOOKMARK(&zb
, db
->db_objset
->os_dsl_dataset
?
683 db
->db_objset
->os_dsl_dataset
->ds_object
: DMU_META_OBJSET
,
684 db
->db
.db_object
, db
->db_level
, db
->db_blkid
);
686 dbuf_add_ref(db
, NULL
);
688 (void) arc_read(zio
, db
->db_objset
->os_spa
, db
->db_blkptr
,
689 dbuf_read_done
, db
, ZIO_PRIORITY_SYNC_READ
,
690 (*flags
& DB_RF_CANFAIL
) ? ZIO_FLAG_CANFAIL
: ZIO_FLAG_MUSTSUCCEED
,
692 if (aflags
& ARC_FLAG_CACHED
)
693 *flags
|= DB_RF_CACHED
;
697 dbuf_read(dmu_buf_impl_t
*db
, zio_t
*zio
, uint32_t flags
)
700 boolean_t havepzio
= (zio
!= NULL
);
705 * We don't have to hold the mutex to check db_state because it
706 * can't be freed while we have a hold on the buffer.
708 ASSERT(!refcount_is_zero(&db
->db_holds
));
710 if (db
->db_state
== DB_NOFILL
)
711 return (SET_ERROR(EIO
));
715 if ((flags
& DB_RF_HAVESTRUCT
) == 0)
716 rw_enter(&dn
->dn_struct_rwlock
, RW_READER
);
718 prefetch
= db
->db_level
== 0 && db
->db_blkid
!= DMU_BONUS_BLKID
&&
719 (flags
& DB_RF_NOPREFETCH
) == 0 && dn
!= NULL
&&
720 DBUF_IS_CACHEABLE(db
);
722 mutex_enter(&db
->db_mtx
);
723 if (db
->db_state
== DB_CACHED
) {
724 mutex_exit(&db
->db_mtx
);
726 dmu_zfetch(&dn
->dn_zfetch
, db
->db
.db_offset
,
727 db
->db
.db_size
, TRUE
);
728 if ((flags
& DB_RF_HAVESTRUCT
) == 0)
729 rw_exit(&dn
->dn_struct_rwlock
);
731 } else if (db
->db_state
== DB_UNCACHED
) {
732 spa_t
*spa
= dn
->dn_objset
->os_spa
;
735 zio
= zio_root(spa
, NULL
, NULL
, ZIO_FLAG_CANFAIL
);
736 dbuf_read_impl(db
, zio
, &flags
);
738 /* dbuf_read_impl has dropped db_mtx for us */
741 dmu_zfetch(&dn
->dn_zfetch
, db
->db
.db_offset
,
742 db
->db
.db_size
, flags
& DB_RF_CACHED
);
744 if ((flags
& DB_RF_HAVESTRUCT
) == 0)
745 rw_exit(&dn
->dn_struct_rwlock
);
752 * Another reader came in while the dbuf was in flight
753 * between UNCACHED and CACHED. Either a writer will finish
754 * writing the buffer (sending the dbuf to CACHED) or the
755 * first reader's request will reach the read_done callback
756 * and send the dbuf to CACHED. Otherwise, a failure
757 * occurred and the dbuf went to UNCACHED.
759 mutex_exit(&db
->db_mtx
);
761 dmu_zfetch(&dn
->dn_zfetch
, db
->db
.db_offset
,
762 db
->db
.db_size
, TRUE
);
763 if ((flags
& DB_RF_HAVESTRUCT
) == 0)
764 rw_exit(&dn
->dn_struct_rwlock
);
767 /* Skip the wait per the caller's request. */
768 mutex_enter(&db
->db_mtx
);
769 if ((flags
& DB_RF_NEVERWAIT
) == 0) {
770 while (db
->db_state
== DB_READ
||
771 db
->db_state
== DB_FILL
) {
772 ASSERT(db
->db_state
== DB_READ
||
773 (flags
& DB_RF_HAVESTRUCT
) == 0);
774 DTRACE_PROBE2(blocked__read
, dmu_buf_impl_t
*,
776 cv_wait(&db
->db_changed
, &db
->db_mtx
);
778 if (db
->db_state
== DB_UNCACHED
)
779 err
= SET_ERROR(EIO
);
781 mutex_exit(&db
->db_mtx
);
784 ASSERT(err
|| havepzio
|| db
->db_state
== DB_CACHED
);
789 dbuf_noread(dmu_buf_impl_t
*db
)
791 ASSERT(!refcount_is_zero(&db
->db_holds
));
792 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
793 mutex_enter(&db
->db_mtx
);
794 while (db
->db_state
== DB_READ
|| db
->db_state
== DB_FILL
)
795 cv_wait(&db
->db_changed
, &db
->db_mtx
);
796 if (db
->db_state
== DB_UNCACHED
) {
797 arc_buf_contents_t type
= DBUF_GET_BUFC_TYPE(db
);
798 spa_t
*spa
= db
->db_objset
->os_spa
;
800 ASSERT(db
->db_buf
== NULL
);
801 ASSERT(db
->db
.db_data
== NULL
);
802 dbuf_set_data(db
, arc_buf_alloc(spa
, db
->db
.db_size
, db
, type
));
803 db
->db_state
= DB_FILL
;
804 } else if (db
->db_state
== DB_NOFILL
) {
807 ASSERT3U(db
->db_state
, ==, DB_CACHED
);
809 mutex_exit(&db
->db_mtx
);
813 * This is our just-in-time copy function. It makes a copy of
814 * buffers, that have been modified in a previous transaction
815 * group, before we modify them in the current active group.
817 * This function is used in two places: when we are dirtying a
818 * buffer for the first time in a txg, and when we are freeing
819 * a range in a dnode that includes this buffer.
821 * Note that when we are called from dbuf_free_range() we do
822 * not put a hold on the buffer, we just traverse the active
823 * dbuf list for the dnode.
826 dbuf_fix_old_data(dmu_buf_impl_t
*db
, uint64_t txg
)
828 dbuf_dirty_record_t
*dr
= db
->db_last_dirty
;
830 ASSERT(MUTEX_HELD(&db
->db_mtx
));
831 ASSERT(db
->db
.db_data
!= NULL
);
832 ASSERT(db
->db_level
== 0);
833 ASSERT(db
->db
.db_object
!= DMU_META_DNODE_OBJECT
);
836 (dr
->dt
.dl
.dr_data
!=
837 ((db
->db_blkid
== DMU_BONUS_BLKID
) ? db
->db
.db_data
: db
->db_buf
)))
841 * If the last dirty record for this dbuf has not yet synced
842 * and its referencing the dbuf data, either:
843 * reset the reference to point to a new copy,
844 * or (if there a no active holders)
845 * just null out the current db_data pointer.
847 ASSERT(dr
->dr_txg
>= txg
- 2);
848 if (db
->db_blkid
== DMU_BONUS_BLKID
) {
849 /* Note that the data bufs here are zio_bufs */
850 dr
->dt
.dl
.dr_data
= zio_buf_alloc(DN_MAX_BONUSLEN
);
851 arc_space_consume(DN_MAX_BONUSLEN
, ARC_SPACE_OTHER
);
852 bcopy(db
->db
.db_data
, dr
->dt
.dl
.dr_data
, DN_MAX_BONUSLEN
);
853 } else if (refcount_count(&db
->db_holds
) > db
->db_dirtycnt
) {
854 int size
= db
->db
.db_size
;
855 arc_buf_contents_t type
= DBUF_GET_BUFC_TYPE(db
);
856 spa_t
*spa
= db
->db_objset
->os_spa
;
858 dr
->dt
.dl
.dr_data
= arc_buf_alloc(spa
, size
, db
, type
);
859 bcopy(db
->db
.db_data
, dr
->dt
.dl
.dr_data
->b_data
, size
);
866 dbuf_unoverride(dbuf_dirty_record_t
*dr
)
868 dmu_buf_impl_t
*db
= dr
->dr_dbuf
;
869 blkptr_t
*bp
= &dr
->dt
.dl
.dr_overridden_by
;
870 uint64_t txg
= dr
->dr_txg
;
872 ASSERT(MUTEX_HELD(&db
->db_mtx
));
873 ASSERT(dr
->dt
.dl
.dr_override_state
!= DR_IN_DMU_SYNC
);
874 ASSERT(db
->db_level
== 0);
876 if (db
->db_blkid
== DMU_BONUS_BLKID
||
877 dr
->dt
.dl
.dr_override_state
== DR_NOT_OVERRIDDEN
)
880 ASSERT(db
->db_data_pending
!= dr
);
882 /* free this block */
883 if (!BP_IS_HOLE(bp
) && !dr
->dt
.dl
.dr_nopwrite
)
884 zio_free(db
->db_objset
->os_spa
, txg
, bp
);
886 dr
->dt
.dl
.dr_override_state
= DR_NOT_OVERRIDDEN
;
887 dr
->dt
.dl
.dr_nopwrite
= B_FALSE
;
890 * Release the already-written buffer, so we leave it in
891 * a consistent dirty state. Note that all callers are
892 * modifying the buffer, so they will immediately do
893 * another (redundant) arc_release(). Therefore, leave
894 * the buf thawed to save the effort of freezing &
895 * immediately re-thawing it.
897 arc_release(dr
->dt
.dl
.dr_data
, db
);
901 * Evict (if its unreferenced) or clear (if its referenced) any level-0
902 * data blocks in the free range, so that any future readers will find
905 * This is a no-op if the dataset is in the middle of an incremental
906 * receive; see comment below for details.
909 dbuf_free_range(dnode_t
*dn
, uint64_t start_blkid
, uint64_t end_blkid
,
912 dmu_buf_impl_t db_search
;
913 dmu_buf_impl_t
*db
, *db_next
;
914 uint64_t txg
= tx
->tx_txg
;
917 if (end_blkid
> dn
->dn_maxblkid
&& (end_blkid
!= DMU_SPILL_BLKID
))
918 end_blkid
= dn
->dn_maxblkid
;
919 dprintf_dnode(dn
, "start=%llu end=%llu\n", start_blkid
, end_blkid
);
921 db_search
.db_level
= 0;
922 db_search
.db_blkid
= start_blkid
;
923 db_search
.db_state
= DB_SEARCH
;
925 mutex_enter(&dn
->dn_dbufs_mtx
);
926 if (start_blkid
>= dn
->dn_unlisted_l0_blkid
) {
927 /* There can't be any dbufs in this range; no need to search. */
929 db
= avl_find(&dn
->dn_dbufs
, &db_search
, &where
);
930 ASSERT3P(db
, ==, NULL
);
931 db
= avl_nearest(&dn
->dn_dbufs
, where
, AVL_AFTER
);
932 ASSERT(db
== NULL
|| db
->db_level
> 0);
934 mutex_exit(&dn
->dn_dbufs_mtx
);
936 } else if (dmu_objset_is_receiving(dn
->dn_objset
)) {
938 * If we are receiving, we expect there to be no dbufs in
939 * the range to be freed, because receive modifies each
940 * block at most once, and in offset order. If this is
941 * not the case, it can lead to performance problems,
942 * so note that we unexpectedly took the slow path.
944 atomic_inc_64(&zfs_free_range_recv_miss
);
947 db
= avl_find(&dn
->dn_dbufs
, &db_search
, &where
);
948 ASSERT3P(db
, ==, NULL
);
949 db
= avl_nearest(&dn
->dn_dbufs
, where
, AVL_AFTER
);
951 for (; db
!= NULL
; db
= db_next
) {
952 db_next
= AVL_NEXT(&dn
->dn_dbufs
, db
);
953 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
955 if (db
->db_level
!= 0 || db
->db_blkid
> end_blkid
) {
958 ASSERT3U(db
->db_blkid
, >=, start_blkid
);
960 /* found a level 0 buffer in the range */
961 mutex_enter(&db
->db_mtx
);
962 if (dbuf_undirty(db
, tx
)) {
963 /* mutex has been dropped and dbuf destroyed */
967 if (db
->db_state
== DB_UNCACHED
||
968 db
->db_state
== DB_NOFILL
||
969 db
->db_state
== DB_EVICTING
) {
970 ASSERT(db
->db
.db_data
== NULL
);
971 mutex_exit(&db
->db_mtx
);
974 if (db
->db_state
== DB_READ
|| db
->db_state
== DB_FILL
) {
975 /* will be handled in dbuf_read_done or dbuf_rele */
976 db
->db_freed_in_flight
= TRUE
;
977 mutex_exit(&db
->db_mtx
);
980 if (refcount_count(&db
->db_holds
) == 0) {
985 /* The dbuf is referenced */
987 if (db
->db_last_dirty
!= NULL
) {
988 dbuf_dirty_record_t
*dr
= db
->db_last_dirty
;
990 if (dr
->dr_txg
== txg
) {
992 * This buffer is "in-use", re-adjust the file
993 * size to reflect that this buffer may
994 * contain new data when we sync.
996 if (db
->db_blkid
!= DMU_SPILL_BLKID
&&
997 db
->db_blkid
> dn
->dn_maxblkid
)
998 dn
->dn_maxblkid
= db
->db_blkid
;
1002 * This dbuf is not dirty in the open context.
1003 * Either uncache it (if its not referenced in
1004 * the open context) or reset its contents to
1007 dbuf_fix_old_data(db
, txg
);
1010 /* clear the contents if its cached */
1011 if (db
->db_state
== DB_CACHED
) {
1012 ASSERT(db
->db
.db_data
!= NULL
);
1013 arc_release(db
->db_buf
, db
);
1014 bzero(db
->db
.db_data
, db
->db
.db_size
);
1015 arc_buf_freeze(db
->db_buf
);
1018 mutex_exit(&db
->db_mtx
);
1020 mutex_exit(&dn
->dn_dbufs_mtx
);
1024 dbuf_block_freeable(dmu_buf_impl_t
*db
)
1026 dsl_dataset_t
*ds
= db
->db_objset
->os_dsl_dataset
;
1027 uint64_t birth_txg
= 0;
1030 * We don't need any locking to protect db_blkptr:
1031 * If it's syncing, then db_last_dirty will be set
1032 * so we'll ignore db_blkptr.
1034 * This logic ensures that only block births for
1035 * filled blocks are considered.
1037 ASSERT(MUTEX_HELD(&db
->db_mtx
));
1038 if (db
->db_last_dirty
&& (db
->db_blkptr
== NULL
||
1039 !BP_IS_HOLE(db
->db_blkptr
))) {
1040 birth_txg
= db
->db_last_dirty
->dr_txg
;
1041 } else if (db
->db_blkptr
!= NULL
&& !BP_IS_HOLE(db
->db_blkptr
)) {
1042 birth_txg
= db
->db_blkptr
->blk_birth
;
1046 * If this block don't exist or is in a snapshot, it can't be freed.
1047 * Don't pass the bp to dsl_dataset_block_freeable() since we
1048 * are holding the db_mtx lock and might deadlock if we are
1049 * prefetching a dedup-ed block.
1052 return (ds
== NULL
||
1053 dsl_dataset_block_freeable(ds
, NULL
, birth_txg
));
1059 dbuf_new_size(dmu_buf_impl_t
*db
, int size
, dmu_tx_t
*tx
)
1061 arc_buf_t
*buf
, *obuf
;
1062 int osize
= db
->db
.db_size
;
1063 arc_buf_contents_t type
= DBUF_GET_BUFC_TYPE(db
);
1066 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
1071 /* XXX does *this* func really need the lock? */
1072 ASSERT(RW_WRITE_HELD(&dn
->dn_struct_rwlock
));
1075 * This call to dmu_buf_will_dirty() with the dn_struct_rwlock held
1076 * is OK, because there can be no other references to the db
1077 * when we are changing its size, so no concurrent DB_FILL can
1081 * XXX we should be doing a dbuf_read, checking the return
1082 * value and returning that up to our callers
1084 dmu_buf_will_dirty(&db
->db
, tx
);
1086 /* create the data buffer for the new block */
1087 buf
= arc_buf_alloc(dn
->dn_objset
->os_spa
, size
, db
, type
);
1089 /* copy old block data to the new block */
1091 bcopy(obuf
->b_data
, buf
->b_data
, MIN(osize
, size
));
1092 /* zero the remainder */
1094 bzero((uint8_t *)buf
->b_data
+ osize
, size
- osize
);
1096 mutex_enter(&db
->db_mtx
);
1097 dbuf_set_data(db
, buf
);
1098 VERIFY(arc_buf_remove_ref(obuf
, db
));
1099 db
->db
.db_size
= size
;
1101 if (db
->db_level
== 0) {
1102 ASSERT3U(db
->db_last_dirty
->dr_txg
, ==, tx
->tx_txg
);
1103 db
->db_last_dirty
->dt
.dl
.dr_data
= buf
;
1105 mutex_exit(&db
->db_mtx
);
1107 dnode_willuse_space(dn
, size
-osize
, tx
);
1112 dbuf_release_bp(dmu_buf_impl_t
*db
)
1114 objset_t
*os
= db
->db_objset
;
1116 ASSERT(dsl_pool_sync_context(dmu_objset_pool(os
)));
1117 ASSERT(arc_released(os
->os_phys_buf
) ||
1118 list_link_active(&os
->os_dsl_dataset
->ds_synced_link
));
1119 ASSERT(db
->db_parent
== NULL
|| arc_released(db
->db_parent
->db_buf
));
1121 (void) arc_release(db
->db_buf
, db
);
1124 dbuf_dirty_record_t
*
1125 dbuf_dirty(dmu_buf_impl_t
*db
, dmu_tx_t
*tx
)
1129 dbuf_dirty_record_t
**drp
, *dr
;
1130 int drop_struct_lock
= FALSE
;
1131 boolean_t do_free_accounting
= B_FALSE
;
1132 int txgoff
= tx
->tx_txg
& TXG_MASK
;
1134 ASSERT(tx
->tx_txg
!= 0);
1135 ASSERT(!refcount_is_zero(&db
->db_holds
));
1136 DMU_TX_DIRTY_BUF(tx
, db
);
1141 * Shouldn't dirty a regular buffer in syncing context. Private
1142 * objects may be dirtied in syncing context, but only if they
1143 * were already pre-dirtied in open context.
1145 ASSERT(!dmu_tx_is_syncing(tx
) ||
1146 BP_IS_HOLE(dn
->dn_objset
->os_rootbp
) ||
1147 DMU_OBJECT_IS_SPECIAL(dn
->dn_object
) ||
1148 dn
->dn_objset
->os_dsl_dataset
== NULL
);
1150 * We make this assert for private objects as well, but after we
1151 * check if we're already dirty. They are allowed to re-dirty
1152 * in syncing context.
1154 ASSERT(dn
->dn_object
== DMU_META_DNODE_OBJECT
||
1155 dn
->dn_dirtyctx
== DN_UNDIRTIED
|| dn
->dn_dirtyctx
==
1156 (dmu_tx_is_syncing(tx
) ? DN_DIRTY_SYNC
: DN_DIRTY_OPEN
));
1158 mutex_enter(&db
->db_mtx
);
1160 * XXX make this true for indirects too? The problem is that
1161 * transactions created with dmu_tx_create_assigned() from
1162 * syncing context don't bother holding ahead.
1164 ASSERT(db
->db_level
!= 0 ||
1165 db
->db_state
== DB_CACHED
|| db
->db_state
== DB_FILL
||
1166 db
->db_state
== DB_NOFILL
);
1168 mutex_enter(&dn
->dn_mtx
);
1170 * Don't set dirtyctx to SYNC if we're just modifying this as we
1171 * initialize the objset.
1173 if (dn
->dn_dirtyctx
== DN_UNDIRTIED
&&
1174 !BP_IS_HOLE(dn
->dn_objset
->os_rootbp
)) {
1176 (dmu_tx_is_syncing(tx
) ? DN_DIRTY_SYNC
: DN_DIRTY_OPEN
);
1177 ASSERT(dn
->dn_dirtyctx_firstset
== NULL
);
1178 dn
->dn_dirtyctx_firstset
= kmem_alloc(1, KM_SLEEP
);
1180 mutex_exit(&dn
->dn_mtx
);
1182 if (db
->db_blkid
== DMU_SPILL_BLKID
)
1183 dn
->dn_have_spill
= B_TRUE
;
1186 * If this buffer is already dirty, we're done.
1188 drp
= &db
->db_last_dirty
;
1189 ASSERT(*drp
== NULL
|| (*drp
)->dr_txg
<= tx
->tx_txg
||
1190 db
->db
.db_object
== DMU_META_DNODE_OBJECT
);
1191 while ((dr
= *drp
) != NULL
&& dr
->dr_txg
> tx
->tx_txg
)
1193 if (dr
&& dr
->dr_txg
== tx
->tx_txg
) {
1196 if (db
->db_level
== 0 && db
->db_blkid
!= DMU_BONUS_BLKID
) {
1198 * If this buffer has already been written out,
1199 * we now need to reset its state.
1201 dbuf_unoverride(dr
);
1202 if (db
->db
.db_object
!= DMU_META_DNODE_OBJECT
&&
1203 db
->db_state
!= DB_NOFILL
)
1204 arc_buf_thaw(db
->db_buf
);
1206 mutex_exit(&db
->db_mtx
);
1211 * Only valid if not already dirty.
1213 ASSERT(dn
->dn_object
== 0 ||
1214 dn
->dn_dirtyctx
== DN_UNDIRTIED
|| dn
->dn_dirtyctx
==
1215 (dmu_tx_is_syncing(tx
) ? DN_DIRTY_SYNC
: DN_DIRTY_OPEN
));
1217 ASSERT3U(dn
->dn_nlevels
, >, db
->db_level
);
1218 ASSERT((dn
->dn_phys
->dn_nlevels
== 0 && db
->db_level
== 0) ||
1219 dn
->dn_phys
->dn_nlevels
> db
->db_level
||
1220 dn
->dn_next_nlevels
[txgoff
] > db
->db_level
||
1221 dn
->dn_next_nlevels
[(tx
->tx_txg
-1) & TXG_MASK
] > db
->db_level
||
1222 dn
->dn_next_nlevels
[(tx
->tx_txg
-2) & TXG_MASK
] > db
->db_level
);
1225 * We should only be dirtying in syncing context if it's the
1226 * mos or we're initializing the os or it's a special object.
1227 * However, we are allowed to dirty in syncing context provided
1228 * we already dirtied it in open context. Hence we must make
1229 * this assertion only if we're not already dirty.
1232 ASSERT(!dmu_tx_is_syncing(tx
) || DMU_OBJECT_IS_SPECIAL(dn
->dn_object
) ||
1233 os
->os_dsl_dataset
== NULL
|| BP_IS_HOLE(os
->os_rootbp
));
1234 ASSERT(db
->db
.db_size
!= 0);
1236 dprintf_dbuf(db
, "size=%llx\n", (u_longlong_t
)db
->db
.db_size
);
1238 if (db
->db_blkid
!= DMU_BONUS_BLKID
) {
1240 * Update the accounting.
1241 * Note: we delay "free accounting" until after we drop
1242 * the db_mtx. This keeps us from grabbing other locks
1243 * (and possibly deadlocking) in bp_get_dsize() while
1244 * also holding the db_mtx.
1246 dnode_willuse_space(dn
, db
->db
.db_size
, tx
);
1247 do_free_accounting
= dbuf_block_freeable(db
);
1251 * If this buffer is dirty in an old transaction group we need
1252 * to make a copy of it so that the changes we make in this
1253 * transaction group won't leak out when we sync the older txg.
1255 dr
= kmem_zalloc(sizeof (dbuf_dirty_record_t
), KM_SLEEP
);
1256 if (db
->db_level
== 0) {
1257 void *data_old
= db
->db_buf
;
1259 if (db
->db_state
!= DB_NOFILL
) {
1260 if (db
->db_blkid
== DMU_BONUS_BLKID
) {
1261 dbuf_fix_old_data(db
, tx
->tx_txg
);
1262 data_old
= db
->db
.db_data
;
1263 } else if (db
->db
.db_object
!= DMU_META_DNODE_OBJECT
) {
1265 * Release the data buffer from the cache so
1266 * that we can modify it without impacting
1267 * possible other users of this cached data
1268 * block. Note that indirect blocks and
1269 * private objects are not released until the
1270 * syncing state (since they are only modified
1273 arc_release(db
->db_buf
, db
);
1274 dbuf_fix_old_data(db
, tx
->tx_txg
);
1275 data_old
= db
->db_buf
;
1277 ASSERT(data_old
!= NULL
);
1279 dr
->dt
.dl
.dr_data
= data_old
;
1281 mutex_init(&dr
->dt
.di
.dr_mtx
, NULL
, MUTEX_DEFAULT
, NULL
);
1282 list_create(&dr
->dt
.di
.dr_children
,
1283 sizeof (dbuf_dirty_record_t
),
1284 offsetof(dbuf_dirty_record_t
, dr_dirty_node
));
1286 if (db
->db_blkid
!= DMU_BONUS_BLKID
&& os
->os_dsl_dataset
!= NULL
)
1287 dr
->dr_accounted
= db
->db
.db_size
;
1289 dr
->dr_txg
= tx
->tx_txg
;
1294 * We could have been freed_in_flight between the dbuf_noread
1295 * and dbuf_dirty. We win, as though the dbuf_noread() had
1296 * happened after the free.
1298 if (db
->db_level
== 0 && db
->db_blkid
!= DMU_BONUS_BLKID
&&
1299 db
->db_blkid
!= DMU_SPILL_BLKID
) {
1300 mutex_enter(&dn
->dn_mtx
);
1301 if (dn
->dn_free_ranges
[txgoff
] != NULL
) {
1302 range_tree_clear(dn
->dn_free_ranges
[txgoff
],
1305 mutex_exit(&dn
->dn_mtx
);
1306 db
->db_freed_in_flight
= FALSE
;
1310 * This buffer is now part of this txg
1312 dbuf_add_ref(db
, (void *)(uintptr_t)tx
->tx_txg
);
1313 db
->db_dirtycnt
+= 1;
1314 ASSERT3U(db
->db_dirtycnt
, <=, 3);
1316 mutex_exit(&db
->db_mtx
);
1318 if (db
->db_blkid
== DMU_BONUS_BLKID
||
1319 db
->db_blkid
== DMU_SPILL_BLKID
) {
1320 mutex_enter(&dn
->dn_mtx
);
1321 ASSERT(!list_link_active(&dr
->dr_dirty_node
));
1322 list_insert_tail(&dn
->dn_dirty_records
[txgoff
], dr
);
1323 mutex_exit(&dn
->dn_mtx
);
1324 dnode_setdirty(dn
, tx
);
1327 } else if (do_free_accounting
) {
1328 blkptr_t
*bp
= db
->db_blkptr
;
1329 int64_t willfree
= (bp
&& !BP_IS_HOLE(bp
)) ?
1330 bp_get_dsize(os
->os_spa
, bp
) : db
->db
.db_size
;
1332 * This is only a guess -- if the dbuf is dirty
1333 * in a previous txg, we don't know how much
1334 * space it will use on disk yet. We should
1335 * really have the struct_rwlock to access
1336 * db_blkptr, but since this is just a guess,
1337 * it's OK if we get an odd answer.
1339 ddt_prefetch(os
->os_spa
, bp
);
1340 dnode_willuse_space(dn
, -willfree
, tx
);
1343 if (!RW_WRITE_HELD(&dn
->dn_struct_rwlock
)) {
1344 rw_enter(&dn
->dn_struct_rwlock
, RW_READER
);
1345 drop_struct_lock
= TRUE
;
1348 if (db
->db_level
== 0) {
1349 dnode_new_blkid(dn
, db
->db_blkid
, tx
, drop_struct_lock
);
1350 ASSERT(dn
->dn_maxblkid
>= db
->db_blkid
);
1353 if (db
->db_level
+1 < dn
->dn_nlevels
) {
1354 dmu_buf_impl_t
*parent
= db
->db_parent
;
1355 dbuf_dirty_record_t
*di
;
1356 int parent_held
= FALSE
;
1358 if (db
->db_parent
== NULL
|| db
->db_parent
== dn
->dn_dbuf
) {
1359 int epbs
= dn
->dn_indblkshift
- SPA_BLKPTRSHIFT
;
1361 parent
= dbuf_hold_level(dn
, db
->db_level
+1,
1362 db
->db_blkid
>> epbs
, FTAG
);
1363 ASSERT(parent
!= NULL
);
1366 if (drop_struct_lock
)
1367 rw_exit(&dn
->dn_struct_rwlock
);
1368 ASSERT3U(db
->db_level
+1, ==, parent
->db_level
);
1369 di
= dbuf_dirty(parent
, tx
);
1371 dbuf_rele(parent
, FTAG
);
1373 mutex_enter(&db
->db_mtx
);
1375 * Since we've dropped the mutex, it's possible that
1376 * dbuf_undirty() might have changed this out from under us.
1378 if (db
->db_last_dirty
== dr
||
1379 dn
->dn_object
== DMU_META_DNODE_OBJECT
) {
1380 mutex_enter(&di
->dt
.di
.dr_mtx
);
1381 ASSERT3U(di
->dr_txg
, ==, tx
->tx_txg
);
1382 ASSERT(!list_link_active(&dr
->dr_dirty_node
));
1383 list_insert_tail(&di
->dt
.di
.dr_children
, dr
);
1384 mutex_exit(&di
->dt
.di
.dr_mtx
);
1387 mutex_exit(&db
->db_mtx
);
1389 ASSERT(db
->db_level
+1 == dn
->dn_nlevels
);
1390 ASSERT(db
->db_blkid
< dn
->dn_nblkptr
);
1391 ASSERT(db
->db_parent
== NULL
|| db
->db_parent
== dn
->dn_dbuf
);
1392 mutex_enter(&dn
->dn_mtx
);
1393 ASSERT(!list_link_active(&dr
->dr_dirty_node
));
1394 list_insert_tail(&dn
->dn_dirty_records
[txgoff
], dr
);
1395 mutex_exit(&dn
->dn_mtx
);
1396 if (drop_struct_lock
)
1397 rw_exit(&dn
->dn_struct_rwlock
);
1400 dnode_setdirty(dn
, tx
);
1406 * Undirty a buffer in the transaction group referenced by the given
1407 * transaction. Return whether this evicted the dbuf.
1410 dbuf_undirty(dmu_buf_impl_t
*db
, dmu_tx_t
*tx
)
1413 uint64_t txg
= tx
->tx_txg
;
1414 dbuf_dirty_record_t
*dr
, **drp
;
1419 * Due to our use of dn_nlevels below, this can only be called
1420 * in open context, unless we are operating on the MOS.
1421 * From syncing context, dn_nlevels may be different from the
1422 * dn_nlevels used when dbuf was dirtied.
1424 ASSERT(db
->db_objset
==
1425 dmu_objset_pool(db
->db_objset
)->dp_meta_objset
||
1426 txg
!= spa_syncing_txg(dmu_objset_spa(db
->db_objset
)));
1427 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
1428 ASSERT0(db
->db_level
);
1429 ASSERT(MUTEX_HELD(&db
->db_mtx
));
1432 * If this buffer is not dirty, we're done.
1434 for (drp
= &db
->db_last_dirty
; (dr
= *drp
) != NULL
; drp
= &dr
->dr_next
)
1435 if (dr
->dr_txg
<= txg
)
1437 if (dr
== NULL
|| dr
->dr_txg
< txg
)
1439 ASSERT(dr
->dr_txg
== txg
);
1440 ASSERT(dr
->dr_dbuf
== db
);
1445 dprintf_dbuf(db
, "size=%llx\n", (u_longlong_t
)db
->db
.db_size
);
1447 ASSERT(db
->db
.db_size
!= 0);
1449 dsl_pool_undirty_space(dmu_objset_pool(dn
->dn_objset
),
1450 dr
->dr_accounted
, txg
);
1455 * Note that there are three places in dbuf_dirty()
1456 * where this dirty record may be put on a list.
1457 * Make sure to do a list_remove corresponding to
1458 * every one of those list_insert calls.
1460 if (dr
->dr_parent
) {
1461 mutex_enter(&dr
->dr_parent
->dt
.di
.dr_mtx
);
1462 list_remove(&dr
->dr_parent
->dt
.di
.dr_children
, dr
);
1463 mutex_exit(&dr
->dr_parent
->dt
.di
.dr_mtx
);
1464 } else if (db
->db_blkid
== DMU_SPILL_BLKID
||
1465 db
->db_level
+ 1 == dn
->dn_nlevels
) {
1466 ASSERT(db
->db_blkptr
== NULL
|| db
->db_parent
== dn
->dn_dbuf
);
1467 mutex_enter(&dn
->dn_mtx
);
1468 list_remove(&dn
->dn_dirty_records
[txg
& TXG_MASK
], dr
);
1469 mutex_exit(&dn
->dn_mtx
);
1473 if (db
->db_state
!= DB_NOFILL
) {
1474 dbuf_unoverride(dr
);
1476 ASSERT(db
->db_buf
!= NULL
);
1477 ASSERT(dr
->dt
.dl
.dr_data
!= NULL
);
1478 if (dr
->dt
.dl
.dr_data
!= db
->db_buf
)
1479 VERIFY(arc_buf_remove_ref(dr
->dt
.dl
.dr_data
, db
));
1482 kmem_free(dr
, sizeof (dbuf_dirty_record_t
));
1484 ASSERT(db
->db_dirtycnt
> 0);
1485 db
->db_dirtycnt
-= 1;
1487 if (refcount_remove(&db
->db_holds
, (void *)(uintptr_t)txg
) == 0) {
1488 arc_buf_t
*buf
= db
->db_buf
;
1490 ASSERT(db
->db_state
== DB_NOFILL
|| arc_released(buf
));
1491 dbuf_clear_data(db
);
1492 VERIFY(arc_buf_remove_ref(buf
, db
));
1501 dmu_buf_will_dirty(dmu_buf_t
*db_fake
, dmu_tx_t
*tx
)
1503 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)db_fake
;
1504 int rf
= DB_RF_MUST_SUCCEED
| DB_RF_NOPREFETCH
;
1506 ASSERT(tx
->tx_txg
!= 0);
1507 ASSERT(!refcount_is_zero(&db
->db_holds
));
1510 if (RW_WRITE_HELD(&DB_DNODE(db
)->dn_struct_rwlock
))
1511 rf
|= DB_RF_HAVESTRUCT
;
1513 (void) dbuf_read(db
, NULL
, rf
);
1514 (void) dbuf_dirty(db
, tx
);
1518 dmu_buf_will_not_fill(dmu_buf_t
*db_fake
, dmu_tx_t
*tx
)
1520 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)db_fake
;
1522 db
->db_state
= DB_NOFILL
;
1524 dmu_buf_will_fill(db_fake
, tx
);
1528 dmu_buf_will_fill(dmu_buf_t
*db_fake
, dmu_tx_t
*tx
)
1530 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)db_fake
;
1532 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
1533 ASSERT(tx
->tx_txg
!= 0);
1534 ASSERT(db
->db_level
== 0);
1535 ASSERT(!refcount_is_zero(&db
->db_holds
));
1537 ASSERT(db
->db
.db_object
!= DMU_META_DNODE_OBJECT
||
1538 dmu_tx_private_ok(tx
));
1541 (void) dbuf_dirty(db
, tx
);
1544 #pragma weak dmu_buf_fill_done = dbuf_fill_done
1547 dbuf_fill_done(dmu_buf_impl_t
*db
, dmu_tx_t
*tx
)
1549 mutex_enter(&db
->db_mtx
);
1552 if (db
->db_state
== DB_FILL
) {
1553 if (db
->db_level
== 0 && db
->db_freed_in_flight
) {
1554 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
1555 /* we were freed while filling */
1556 /* XXX dbuf_undirty? */
1557 bzero(db
->db
.db_data
, db
->db
.db_size
);
1558 db
->db_freed_in_flight
= FALSE
;
1560 db
->db_state
= DB_CACHED
;
1561 cv_broadcast(&db
->db_changed
);
1563 mutex_exit(&db
->db_mtx
);
1567 dmu_buf_write_embedded(dmu_buf_t
*dbuf
, void *data
,
1568 bp_embedded_type_t etype
, enum zio_compress comp
,
1569 int uncompressed_size
, int compressed_size
, int byteorder
,
1572 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)dbuf
;
1573 struct dirty_leaf
*dl
;
1574 dmu_object_type_t type
;
1577 type
= DB_DNODE(db
)->dn_type
;
1580 ASSERT0(db
->db_level
);
1581 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
1583 dmu_buf_will_not_fill(dbuf
, tx
);
1585 ASSERT3U(db
->db_last_dirty
->dr_txg
, ==, tx
->tx_txg
);
1586 dl
= &db
->db_last_dirty
->dt
.dl
;
1587 encode_embedded_bp_compressed(&dl
->dr_overridden_by
,
1588 data
, comp
, uncompressed_size
, compressed_size
);
1589 BPE_SET_ETYPE(&dl
->dr_overridden_by
, etype
);
1590 BP_SET_TYPE(&dl
->dr_overridden_by
, type
);
1591 BP_SET_LEVEL(&dl
->dr_overridden_by
, 0);
1592 BP_SET_BYTEORDER(&dl
->dr_overridden_by
, byteorder
);
1594 dl
->dr_override_state
= DR_OVERRIDDEN
;
1595 dl
->dr_overridden_by
.blk_birth
= db
->db_last_dirty
->dr_txg
;
1599 * Directly assign a provided arc buf to a given dbuf if it's not referenced
1600 * by anybody except our caller. Otherwise copy arcbuf's contents to dbuf.
1603 dbuf_assign_arcbuf(dmu_buf_impl_t
*db
, arc_buf_t
*buf
, dmu_tx_t
*tx
)
1605 ASSERT(!refcount_is_zero(&db
->db_holds
));
1606 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
1607 ASSERT(db
->db_level
== 0);
1608 ASSERT(DBUF_GET_BUFC_TYPE(db
) == ARC_BUFC_DATA
);
1609 ASSERT(buf
!= NULL
);
1610 ASSERT(arc_buf_size(buf
) == db
->db
.db_size
);
1611 ASSERT(tx
->tx_txg
!= 0);
1613 arc_return_buf(buf
, db
);
1614 ASSERT(arc_released(buf
));
1616 mutex_enter(&db
->db_mtx
);
1618 while (db
->db_state
== DB_READ
|| db
->db_state
== DB_FILL
)
1619 cv_wait(&db
->db_changed
, &db
->db_mtx
);
1621 ASSERT(db
->db_state
== DB_CACHED
|| db
->db_state
== DB_UNCACHED
);
1623 if (db
->db_state
== DB_CACHED
&&
1624 refcount_count(&db
->db_holds
) - 1 > db
->db_dirtycnt
) {
1625 mutex_exit(&db
->db_mtx
);
1626 (void) dbuf_dirty(db
, tx
);
1627 bcopy(buf
->b_data
, db
->db
.db_data
, db
->db
.db_size
);
1628 VERIFY(arc_buf_remove_ref(buf
, db
));
1629 xuio_stat_wbuf_copied();
1633 xuio_stat_wbuf_nocopy();
1634 if (db
->db_state
== DB_CACHED
) {
1635 dbuf_dirty_record_t
*dr
= db
->db_last_dirty
;
1637 ASSERT(db
->db_buf
!= NULL
);
1638 if (dr
!= NULL
&& dr
->dr_txg
== tx
->tx_txg
) {
1639 ASSERT(dr
->dt
.dl
.dr_data
== db
->db_buf
);
1640 if (!arc_released(db
->db_buf
)) {
1641 ASSERT(dr
->dt
.dl
.dr_override_state
==
1643 arc_release(db
->db_buf
, db
);
1645 dr
->dt
.dl
.dr_data
= buf
;
1646 VERIFY(arc_buf_remove_ref(db
->db_buf
, db
));
1647 } else if (dr
== NULL
|| dr
->dt
.dl
.dr_data
!= db
->db_buf
) {
1648 arc_release(db
->db_buf
, db
);
1649 VERIFY(arc_buf_remove_ref(db
->db_buf
, db
));
1653 ASSERT(db
->db_buf
== NULL
);
1654 dbuf_set_data(db
, buf
);
1655 db
->db_state
= DB_FILL
;
1656 mutex_exit(&db
->db_mtx
);
1657 (void) dbuf_dirty(db
, tx
);
1658 dmu_buf_fill_done(&db
->db
, tx
);
1662 * "Clear" the contents of this dbuf. This will mark the dbuf
1663 * EVICTING and clear *most* of its references. Unfortunately,
1664 * when we are not holding the dn_dbufs_mtx, we can't clear the
1665 * entry in the dn_dbufs list. We have to wait until dbuf_destroy()
1666 * in this case. For callers from the DMU we will usually see:
1667 * dbuf_clear()->arc_clear_callback()->dbuf_do_evict()->dbuf_destroy()
1668 * For the arc callback, we will usually see:
1669 * dbuf_do_evict()->dbuf_clear();dbuf_destroy()
1670 * Sometimes, though, we will get a mix of these two:
1671 * DMU: dbuf_clear()->arc_clear_callback()
1672 * ARC: dbuf_do_evict()->dbuf_destroy()
1674 * This routine will dissociate the dbuf from the arc, by calling
1675 * arc_clear_callback(), but will not evict the data from the ARC.
1678 dbuf_clear(dmu_buf_impl_t
*db
)
1681 dmu_buf_impl_t
*parent
= db
->db_parent
;
1682 dmu_buf_impl_t
*dndb
;
1683 boolean_t dbuf_gone
= B_FALSE
;
1685 ASSERT(MUTEX_HELD(&db
->db_mtx
));
1686 ASSERT(refcount_is_zero(&db
->db_holds
));
1688 dbuf_evict_user(db
);
1690 if (db
->db_state
== DB_CACHED
) {
1691 ASSERT(db
->db
.db_data
!= NULL
);
1692 if (db
->db_blkid
== DMU_BONUS_BLKID
) {
1693 zio_buf_free(db
->db
.db_data
, DN_MAX_BONUSLEN
);
1694 arc_space_return(DN_MAX_BONUSLEN
, ARC_SPACE_OTHER
);
1696 db
->db
.db_data
= NULL
;
1697 db
->db_state
= DB_UNCACHED
;
1700 ASSERT(db
->db_state
== DB_UNCACHED
|| db
->db_state
== DB_NOFILL
);
1701 ASSERT(db
->db_data_pending
== NULL
);
1703 db
->db_state
= DB_EVICTING
;
1704 db
->db_blkptr
= NULL
;
1709 if (db
->db_blkid
!= DMU_BONUS_BLKID
&& MUTEX_HELD(&dn
->dn_dbufs_mtx
)) {
1710 avl_remove(&dn
->dn_dbufs
, db
);
1711 atomic_dec_32(&dn
->dn_dbufs_count
);
1715 * Decrementing the dbuf count means that the hold corresponding
1716 * to the removed dbuf is no longer discounted in dnode_move(),
1717 * so the dnode cannot be moved until after we release the hold.
1718 * The membar_producer() ensures visibility of the decremented
1719 * value in dnode_move(), since DB_DNODE_EXIT doesn't actually
1723 db
->db_dnode_handle
= NULL
;
1729 dbuf_gone
= arc_clear_callback(db
->db_buf
);
1732 mutex_exit(&db
->db_mtx
);
1735 * If this dbuf is referenced from an indirect dbuf,
1736 * decrement the ref count on the indirect dbuf.
1738 if (parent
&& parent
!= dndb
)
1739 dbuf_rele(parent
, db
);
1743 * Note: While bpp will always be updated if the function returns success,
1744 * parentp will not be updated if the dnode does not have dn_dbuf filled in;
1745 * this happens when the dnode is the meta-dnode, or a userused or groupused
1749 dbuf_findbp(dnode_t
*dn
, int level
, uint64_t blkid
, int fail_sparse
,
1750 dmu_buf_impl_t
**parentp
, blkptr_t
**bpp
)
1757 ASSERT(blkid
!= DMU_BONUS_BLKID
);
1759 if (blkid
== DMU_SPILL_BLKID
) {
1760 mutex_enter(&dn
->dn_mtx
);
1761 if (dn
->dn_have_spill
&&
1762 (dn
->dn_phys
->dn_flags
& DNODE_FLAG_SPILL_BLKPTR
))
1763 *bpp
= &dn
->dn_phys
->dn_spill
;
1766 dbuf_add_ref(dn
->dn_dbuf
, NULL
);
1767 *parentp
= dn
->dn_dbuf
;
1768 mutex_exit(&dn
->dn_mtx
);
1772 if (dn
->dn_phys
->dn_nlevels
== 0)
1775 nlevels
= dn
->dn_phys
->dn_nlevels
;
1777 epbs
= dn
->dn_indblkshift
- SPA_BLKPTRSHIFT
;
1779 ASSERT3U(level
* epbs
, <, 64);
1780 ASSERT(RW_LOCK_HELD(&dn
->dn_struct_rwlock
));
1781 if (level
>= nlevels
||
1782 (blkid
> (dn
->dn_phys
->dn_maxblkid
>> (level
* epbs
)))) {
1783 /* the buffer has no parent yet */
1784 return (SET_ERROR(ENOENT
));
1785 } else if (level
< nlevels
-1) {
1786 /* this block is referenced from an indirect block */
1787 int err
= dbuf_hold_impl(dn
, level
+1,
1788 blkid
>> epbs
, fail_sparse
, FALSE
, NULL
, parentp
);
1791 err
= dbuf_read(*parentp
, NULL
,
1792 (DB_RF_HAVESTRUCT
| DB_RF_NOPREFETCH
| DB_RF_CANFAIL
));
1794 dbuf_rele(*parentp
, NULL
);
1798 *bpp
= ((blkptr_t
*)(*parentp
)->db
.db_data
) +
1799 (blkid
& ((1ULL << epbs
) - 1));
1802 /* the block is referenced from the dnode */
1803 ASSERT3U(level
, ==, nlevels
-1);
1804 ASSERT(dn
->dn_phys
->dn_nblkptr
== 0 ||
1805 blkid
< dn
->dn_phys
->dn_nblkptr
);
1807 dbuf_add_ref(dn
->dn_dbuf
, NULL
);
1808 *parentp
= dn
->dn_dbuf
;
1810 *bpp
= &dn
->dn_phys
->dn_blkptr
[blkid
];
1815 static dmu_buf_impl_t
*
1816 dbuf_create(dnode_t
*dn
, uint8_t level
, uint64_t blkid
,
1817 dmu_buf_impl_t
*parent
, blkptr_t
*blkptr
)
1819 objset_t
*os
= dn
->dn_objset
;
1820 dmu_buf_impl_t
*db
, *odb
;
1822 ASSERT(RW_LOCK_HELD(&dn
->dn_struct_rwlock
));
1823 ASSERT(dn
->dn_type
!= DMU_OT_NONE
);
1825 db
= kmem_cache_alloc(dbuf_cache
, KM_SLEEP
);
1828 db
->db
.db_object
= dn
->dn_object
;
1829 db
->db_level
= level
;
1830 db
->db_blkid
= blkid
;
1831 db
->db_last_dirty
= NULL
;
1832 db
->db_dirtycnt
= 0;
1833 db
->db_dnode_handle
= dn
->dn_handle
;
1834 db
->db_parent
= parent
;
1835 db
->db_blkptr
= blkptr
;
1838 db
->db_immediate_evict
= 0;
1839 db
->db_freed_in_flight
= 0;
1841 if (blkid
== DMU_BONUS_BLKID
) {
1842 ASSERT3P(parent
, ==, dn
->dn_dbuf
);
1843 db
->db
.db_size
= DN_MAX_BONUSLEN
-
1844 (dn
->dn_nblkptr
-1) * sizeof (blkptr_t
);
1845 ASSERT3U(db
->db
.db_size
, >=, dn
->dn_bonuslen
);
1846 db
->db
.db_offset
= DMU_BONUS_BLKID
;
1847 db
->db_state
= DB_UNCACHED
;
1848 /* the bonus dbuf is not placed in the hash table */
1849 arc_space_consume(sizeof (dmu_buf_impl_t
), ARC_SPACE_OTHER
);
1851 } else if (blkid
== DMU_SPILL_BLKID
) {
1852 db
->db
.db_size
= (blkptr
!= NULL
) ?
1853 BP_GET_LSIZE(blkptr
) : SPA_MINBLOCKSIZE
;
1854 db
->db
.db_offset
= 0;
1857 db
->db_level
? 1 << dn
->dn_indblkshift
: dn
->dn_datablksz
;
1858 db
->db
.db_size
= blocksize
;
1859 db
->db
.db_offset
= db
->db_blkid
* blocksize
;
1863 * Hold the dn_dbufs_mtx while we get the new dbuf
1864 * in the hash table *and* added to the dbufs list.
1865 * This prevents a possible deadlock with someone
1866 * trying to look up this dbuf before its added to the
1869 mutex_enter(&dn
->dn_dbufs_mtx
);
1870 db
->db_state
= DB_EVICTING
;
1871 if ((odb
= dbuf_hash_insert(db
)) != NULL
) {
1872 /* someone else inserted it first */
1873 kmem_cache_free(dbuf_cache
, db
);
1874 mutex_exit(&dn
->dn_dbufs_mtx
);
1877 avl_add(&dn
->dn_dbufs
, db
);
1878 if (db
->db_level
== 0 && db
->db_blkid
>=
1879 dn
->dn_unlisted_l0_blkid
)
1880 dn
->dn_unlisted_l0_blkid
= db
->db_blkid
+ 1;
1881 db
->db_state
= DB_UNCACHED
;
1882 mutex_exit(&dn
->dn_dbufs_mtx
);
1883 arc_space_consume(sizeof (dmu_buf_impl_t
), ARC_SPACE_OTHER
);
1885 if (parent
&& parent
!= dn
->dn_dbuf
)
1886 dbuf_add_ref(parent
, db
);
1888 ASSERT(dn
->dn_object
== DMU_META_DNODE_OBJECT
||
1889 refcount_count(&dn
->dn_holds
) > 0);
1890 (void) refcount_add(&dn
->dn_holds
, db
);
1891 atomic_inc_32(&dn
->dn_dbufs_count
);
1893 dprintf_dbuf(db
, "db=%p\n", db
);
1899 dbuf_do_evict(void *private)
1901 dmu_buf_impl_t
*db
= private;
1903 if (!MUTEX_HELD(&db
->db_mtx
))
1904 mutex_enter(&db
->db_mtx
);
1906 ASSERT(refcount_is_zero(&db
->db_holds
));
1908 if (db
->db_state
!= DB_EVICTING
) {
1909 ASSERT(db
->db_state
== DB_CACHED
);
1914 mutex_exit(&db
->db_mtx
);
1921 dbuf_destroy(dmu_buf_impl_t
*db
)
1923 ASSERT(refcount_is_zero(&db
->db_holds
));
1925 if (db
->db_blkid
!= DMU_BONUS_BLKID
) {
1927 * If this dbuf is still on the dn_dbufs list,
1928 * remove it from that list.
1930 if (db
->db_dnode_handle
!= NULL
) {
1935 mutex_enter(&dn
->dn_dbufs_mtx
);
1936 avl_remove(&dn
->dn_dbufs
, db
);
1937 atomic_dec_32(&dn
->dn_dbufs_count
);
1938 mutex_exit(&dn
->dn_dbufs_mtx
);
1941 * Decrementing the dbuf count means that the hold
1942 * corresponding to the removed dbuf is no longer
1943 * discounted in dnode_move(), so the dnode cannot be
1944 * moved until after we release the hold.
1947 db
->db_dnode_handle
= NULL
;
1949 dbuf_hash_remove(db
);
1951 db
->db_parent
= NULL
;
1954 ASSERT(db
->db
.db_data
== NULL
);
1955 ASSERT(db
->db_hash_next
== NULL
);
1956 ASSERT(db
->db_blkptr
== NULL
);
1957 ASSERT(db
->db_data_pending
== NULL
);
1959 kmem_cache_free(dbuf_cache
, db
);
1960 arc_space_return(sizeof (dmu_buf_impl_t
), ARC_SPACE_OTHER
);
1963 typedef struct dbuf_prefetch_arg
{
1964 spa_t
*dpa_spa
; /* The spa to issue the prefetch in. */
1965 zbookmark_phys_t dpa_zb
; /* The target block to prefetch. */
1966 int dpa_epbs
; /* Entries (blkptr_t's) Per Block Shift. */
1967 int dpa_curlevel
; /* The current level that we're reading */
1968 zio_priority_t dpa_prio
; /* The priority I/Os should be issued at. */
1969 zio_t
*dpa_zio
; /* The parent zio_t for all prefetches. */
1970 arc_flags_t dpa_aflags
; /* Flags to pass to the final prefetch. */
1971 } dbuf_prefetch_arg_t
;
1974 * Actually issue the prefetch read for the block given.
1977 dbuf_issue_final_prefetch(dbuf_prefetch_arg_t
*dpa
, blkptr_t
*bp
)
1979 if (BP_IS_HOLE(bp
) || BP_IS_EMBEDDED(bp
))
1982 arc_flags_t aflags
=
1983 dpa
->dpa_aflags
| ARC_FLAG_NOWAIT
| ARC_FLAG_PREFETCH
;
1985 ASSERT3U(dpa
->dpa_curlevel
, ==, BP_GET_LEVEL(bp
));
1986 ASSERT3U(dpa
->dpa_curlevel
, ==, dpa
->dpa_zb
.zb_level
);
1987 ASSERT(dpa
->dpa_zio
!= NULL
);
1988 (void) arc_read(dpa
->dpa_zio
, dpa
->dpa_spa
, bp
, NULL
, NULL
,
1989 dpa
->dpa_prio
, ZIO_FLAG_CANFAIL
| ZIO_FLAG_SPECULATIVE
,
1990 &aflags
, &dpa
->dpa_zb
);
1994 * Called when an indirect block above our prefetch target is read in. This
1995 * will either read in the next indirect block down the tree or issue the actual
1996 * prefetch if the next block down is our target.
1999 dbuf_prefetch_indirect_done(zio_t
*zio
, arc_buf_t
*abuf
, void *private)
2001 dbuf_prefetch_arg_t
*dpa
= private;
2003 ASSERT3S(dpa
->dpa_zb
.zb_level
, <, dpa
->dpa_curlevel
);
2004 ASSERT3S(dpa
->dpa_curlevel
, >, 0);
2006 ASSERT3S(BP_GET_LEVEL(zio
->io_bp
), ==, dpa
->dpa_curlevel
);
2007 ASSERT3U(BP_GET_LSIZE(zio
->io_bp
), ==, zio
->io_size
);
2008 ASSERT3P(zio
->io_spa
, ==, dpa
->dpa_spa
);
2011 dpa
->dpa_curlevel
--;
2013 uint64_t nextblkid
= dpa
->dpa_zb
.zb_blkid
>>
2014 (dpa
->dpa_epbs
* (dpa
->dpa_curlevel
- dpa
->dpa_zb
.zb_level
));
2015 blkptr_t
*bp
= ((blkptr_t
*)abuf
->b_data
) +
2016 P2PHASE(nextblkid
, 1ULL << dpa
->dpa_epbs
);
2017 if (BP_IS_HOLE(bp
) || (zio
!= NULL
&& zio
->io_error
!= 0)) {
2018 kmem_free(dpa
, sizeof (*dpa
));
2019 } else if (dpa
->dpa_curlevel
== dpa
->dpa_zb
.zb_level
) {
2020 ASSERT3U(nextblkid
, ==, dpa
->dpa_zb
.zb_blkid
);
2021 dbuf_issue_final_prefetch(dpa
, bp
);
2022 kmem_free(dpa
, sizeof (*dpa
));
2024 arc_flags_t iter_aflags
= ARC_FLAG_NOWAIT
;
2025 zbookmark_phys_t zb
;
2027 ASSERT3U(dpa
->dpa_curlevel
, ==, BP_GET_LEVEL(bp
));
2029 SET_BOOKMARK(&zb
, dpa
->dpa_zb
.zb_objset
,
2030 dpa
->dpa_zb
.zb_object
, dpa
->dpa_curlevel
, nextblkid
);
2032 (void) arc_read(dpa
->dpa_zio
, dpa
->dpa_spa
,
2033 bp
, dbuf_prefetch_indirect_done
, dpa
, dpa
->dpa_prio
,
2034 ZIO_FLAG_CANFAIL
| ZIO_FLAG_SPECULATIVE
,
2037 (void) arc_buf_remove_ref(abuf
, private);
2041 * Issue prefetch reads for the given block on the given level. If the indirect
2042 * blocks above that block are not in memory, we will read them in
2043 * asynchronously. As a result, this call never blocks waiting for a read to
2047 dbuf_prefetch(dnode_t
*dn
, int64_t level
, uint64_t blkid
, zio_priority_t prio
,
2051 int epbs
, nlevels
, curlevel
;
2054 ASSERT(blkid
!= DMU_BONUS_BLKID
);
2055 ASSERT(RW_LOCK_HELD(&dn
->dn_struct_rwlock
));
2057 if (dnode_block_freed(dn
, blkid
))
2061 * This dnode hasn't been written to disk yet, so there's nothing to
2064 nlevels
= dn
->dn_phys
->dn_nlevels
;
2065 if (level
>= nlevels
|| dn
->dn_phys
->dn_nblkptr
== 0)
2068 epbs
= dn
->dn_phys
->dn_indblkshift
- SPA_BLKPTRSHIFT
;
2069 if (dn
->dn_phys
->dn_maxblkid
< blkid
<< (epbs
* level
))
2072 dmu_buf_impl_t
*db
= dbuf_find(dn
->dn_objset
, dn
->dn_object
,
2075 mutex_exit(&db
->db_mtx
);
2077 * This dbuf already exists. It is either CACHED, or
2078 * (we assume) about to be read or filled.
2084 * Find the closest ancestor (indirect block) of the target block
2085 * that is present in the cache. In this indirect block, we will
2086 * find the bp that is at curlevel, curblkid.
2090 while (curlevel
< nlevels
- 1) {
2091 int parent_level
= curlevel
+ 1;
2092 uint64_t parent_blkid
= curblkid
>> epbs
;
2095 if (dbuf_hold_impl(dn
, parent_level
, parent_blkid
,
2096 FALSE
, TRUE
, FTAG
, &db
) == 0) {
2097 blkptr_t
*bpp
= db
->db_buf
->b_data
;
2098 bp
= bpp
[P2PHASE(curblkid
, 1 << epbs
)];
2099 dbuf_rele(db
, FTAG
);
2103 curlevel
= parent_level
;
2104 curblkid
= parent_blkid
;
2107 if (curlevel
== nlevels
- 1) {
2108 /* No cached indirect blocks found. */
2109 ASSERT3U(curblkid
, <, dn
->dn_phys
->dn_nblkptr
);
2110 bp
= dn
->dn_phys
->dn_blkptr
[curblkid
];
2112 if (BP_IS_HOLE(&bp
))
2115 ASSERT3U(curlevel
, ==, BP_GET_LEVEL(&bp
));
2117 zio_t
*pio
= zio_root(dmu_objset_spa(dn
->dn_objset
), NULL
, NULL
,
2120 dbuf_prefetch_arg_t
*dpa
= kmem_zalloc(sizeof (*dpa
), KM_SLEEP
);
2121 dsl_dataset_t
*ds
= dn
->dn_objset
->os_dsl_dataset
;
2122 SET_BOOKMARK(&dpa
->dpa_zb
, ds
!= NULL
? ds
->ds_object
: DMU_META_OBJSET
,
2123 dn
->dn_object
, level
, blkid
);
2124 dpa
->dpa_curlevel
= curlevel
;
2125 dpa
->dpa_prio
= prio
;
2126 dpa
->dpa_aflags
= aflags
;
2127 dpa
->dpa_spa
= dn
->dn_objset
->os_spa
;
2128 dpa
->dpa_epbs
= epbs
;
2132 * If we have the indirect just above us, no need to do the asynchronous
2133 * prefetch chain; we'll just run the last step ourselves. If we're at
2134 * a higher level, though, we want to issue the prefetches for all the
2135 * indirect blocks asynchronously, so we can go on with whatever we were
2138 if (curlevel
== level
) {
2139 ASSERT3U(curblkid
, ==, blkid
);
2140 dbuf_issue_final_prefetch(dpa
, &bp
);
2141 kmem_free(dpa
, sizeof (*dpa
));
2143 arc_flags_t iter_aflags
= ARC_FLAG_NOWAIT
;
2144 zbookmark_phys_t zb
;
2146 SET_BOOKMARK(&zb
, ds
!= NULL
? ds
->ds_object
: DMU_META_OBJSET
,
2147 dn
->dn_object
, curlevel
, curblkid
);
2148 (void) arc_read(dpa
->dpa_zio
, dpa
->dpa_spa
,
2149 &bp
, dbuf_prefetch_indirect_done
, dpa
, prio
,
2150 ZIO_FLAG_CANFAIL
| ZIO_FLAG_SPECULATIVE
,
2154 * We use pio here instead of dpa_zio since it's possible that
2155 * dpa may have already been freed.
2161 * Returns with db_holds incremented, and db_mtx not held.
2162 * Note: dn_struct_rwlock must be held.
2165 dbuf_hold_impl(dnode_t
*dn
, uint8_t level
, uint64_t blkid
,
2166 boolean_t fail_sparse
, boolean_t fail_uncached
,
2167 void *tag
, dmu_buf_impl_t
**dbp
)
2169 dmu_buf_impl_t
*db
, *parent
= NULL
;
2171 ASSERT(blkid
!= DMU_BONUS_BLKID
);
2172 ASSERT(RW_LOCK_HELD(&dn
->dn_struct_rwlock
));
2173 ASSERT3U(dn
->dn_nlevels
, >, level
);
2177 /* dbuf_find() returns with db_mtx held */
2178 db
= dbuf_find(dn
->dn_objset
, dn
->dn_object
, level
, blkid
);
2181 blkptr_t
*bp
= NULL
;
2185 return (SET_ERROR(ENOENT
));
2187 ASSERT3P(parent
, ==, NULL
);
2188 err
= dbuf_findbp(dn
, level
, blkid
, fail_sparse
, &parent
, &bp
);
2190 if (err
== 0 && bp
&& BP_IS_HOLE(bp
))
2191 err
= SET_ERROR(ENOENT
);
2194 dbuf_rele(parent
, NULL
);
2198 if (err
&& err
!= ENOENT
)
2200 db
= dbuf_create(dn
, level
, blkid
, parent
, bp
);
2203 if (fail_uncached
&& db
->db_state
!= DB_CACHED
) {
2204 mutex_exit(&db
->db_mtx
);
2205 return (SET_ERROR(ENOENT
));
2208 if (db
->db_buf
&& refcount_is_zero(&db
->db_holds
)) {
2209 arc_buf_add_ref(db
->db_buf
, db
);
2210 if (db
->db_buf
->b_data
== NULL
) {
2213 dbuf_rele(parent
, NULL
);
2218 ASSERT3P(db
->db
.db_data
, ==, db
->db_buf
->b_data
);
2221 ASSERT(db
->db_buf
== NULL
|| arc_referenced(db
->db_buf
));
2224 * If this buffer is currently syncing out, and we are are
2225 * still referencing it from db_data, we need to make a copy
2226 * of it in case we decide we want to dirty it again in this txg.
2228 if (db
->db_level
== 0 && db
->db_blkid
!= DMU_BONUS_BLKID
&&
2229 dn
->dn_object
!= DMU_META_DNODE_OBJECT
&&
2230 db
->db_state
== DB_CACHED
&& db
->db_data_pending
) {
2231 dbuf_dirty_record_t
*dr
= db
->db_data_pending
;
2233 if (dr
->dt
.dl
.dr_data
== db
->db_buf
) {
2234 arc_buf_contents_t type
= DBUF_GET_BUFC_TYPE(db
);
2237 arc_buf_alloc(dn
->dn_objset
->os_spa
,
2238 db
->db
.db_size
, db
, type
));
2239 bcopy(dr
->dt
.dl
.dr_data
->b_data
, db
->db
.db_data
,
2244 (void) refcount_add(&db
->db_holds
, tag
);
2246 mutex_exit(&db
->db_mtx
);
2248 /* NOTE: we can't rele the parent until after we drop the db_mtx */
2250 dbuf_rele(parent
, NULL
);
2252 ASSERT3P(DB_DNODE(db
), ==, dn
);
2253 ASSERT3U(db
->db_blkid
, ==, blkid
);
2254 ASSERT3U(db
->db_level
, ==, level
);
2261 dbuf_hold(dnode_t
*dn
, uint64_t blkid
, void *tag
)
2263 return (dbuf_hold_level(dn
, 0, blkid
, tag
));
2267 dbuf_hold_level(dnode_t
*dn
, int level
, uint64_t blkid
, void *tag
)
2270 int err
= dbuf_hold_impl(dn
, level
, blkid
, FALSE
, FALSE
, tag
, &db
);
2271 return (err
? NULL
: db
);
2275 dbuf_create_bonus(dnode_t
*dn
)
2277 ASSERT(RW_WRITE_HELD(&dn
->dn_struct_rwlock
));
2279 ASSERT(dn
->dn_bonus
== NULL
);
2280 dn
->dn_bonus
= dbuf_create(dn
, 0, DMU_BONUS_BLKID
, dn
->dn_dbuf
, NULL
);
2284 dbuf_spill_set_blksz(dmu_buf_t
*db_fake
, uint64_t blksz
, dmu_tx_t
*tx
)
2286 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)db_fake
;
2289 if (db
->db_blkid
!= DMU_SPILL_BLKID
)
2290 return (SET_ERROR(ENOTSUP
));
2292 blksz
= SPA_MINBLOCKSIZE
;
2293 ASSERT3U(blksz
, <=, spa_maxblocksize(dmu_objset_spa(db
->db_objset
)));
2294 blksz
= P2ROUNDUP(blksz
, SPA_MINBLOCKSIZE
);
2298 rw_enter(&dn
->dn_struct_rwlock
, RW_WRITER
);
2299 dbuf_new_size(db
, blksz
, tx
);
2300 rw_exit(&dn
->dn_struct_rwlock
);
2307 dbuf_rm_spill(dnode_t
*dn
, dmu_tx_t
*tx
)
2309 dbuf_free_range(dn
, DMU_SPILL_BLKID
, DMU_SPILL_BLKID
, tx
);
2312 #pragma weak dmu_buf_add_ref = dbuf_add_ref
2314 dbuf_add_ref(dmu_buf_impl_t
*db
, void *tag
)
2316 int64_t holds
= refcount_add(&db
->db_holds
, tag
);
2320 #pragma weak dmu_buf_try_add_ref = dbuf_try_add_ref
2322 dbuf_try_add_ref(dmu_buf_t
*db_fake
, objset_t
*os
, uint64_t obj
, uint64_t blkid
,
2325 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)db_fake
;
2326 dmu_buf_impl_t
*found_db
;
2327 boolean_t result
= B_FALSE
;
2329 if (db
->db_blkid
== DMU_BONUS_BLKID
)
2330 found_db
= dbuf_find_bonus(os
, obj
);
2332 found_db
= dbuf_find(os
, obj
, 0, blkid
);
2334 if (found_db
!= NULL
) {
2335 if (db
== found_db
&& dbuf_refcount(db
) > db
->db_dirtycnt
) {
2336 (void) refcount_add(&db
->db_holds
, tag
);
2339 mutex_exit(&db
->db_mtx
);
2345 * If you call dbuf_rele() you had better not be referencing the dnode handle
2346 * unless you have some other direct or indirect hold on the dnode. (An indirect
2347 * hold is a hold on one of the dnode's dbufs, including the bonus buffer.)
2348 * Without that, the dbuf_rele() could lead to a dnode_rele() followed by the
2349 * dnode's parent dbuf evicting its dnode handles.
2352 dbuf_rele(dmu_buf_impl_t
*db
, void *tag
)
2354 mutex_enter(&db
->db_mtx
);
2355 dbuf_rele_and_unlock(db
, tag
);
2359 dmu_buf_rele(dmu_buf_t
*db
, void *tag
)
2361 dbuf_rele((dmu_buf_impl_t
*)db
, tag
);
2365 * dbuf_rele() for an already-locked dbuf. This is necessary to allow
2366 * db_dirtycnt and db_holds to be updated atomically.
2369 dbuf_rele_and_unlock(dmu_buf_impl_t
*db
, void *tag
)
2373 ASSERT(MUTEX_HELD(&db
->db_mtx
));
2377 * Remove the reference to the dbuf before removing its hold on the
2378 * dnode so we can guarantee in dnode_move() that a referenced bonus
2379 * buffer has a corresponding dnode hold.
2381 holds
= refcount_remove(&db
->db_holds
, tag
);
2385 * We can't freeze indirects if there is a possibility that they
2386 * may be modified in the current syncing context.
2388 if (db
->db_buf
&& holds
== (db
->db_level
== 0 ? db
->db_dirtycnt
: 0))
2389 arc_buf_freeze(db
->db_buf
);
2391 if (holds
== db
->db_dirtycnt
&&
2392 db
->db_level
== 0 && db
->db_immediate_evict
)
2393 dbuf_evict_user(db
);
2396 if (db
->db_blkid
== DMU_BONUS_BLKID
) {
2400 * If the dnode moves here, we cannot cross this
2401 * barrier until the move completes.
2406 atomic_dec_32(&dn
->dn_dbufs_count
);
2409 * Decrementing the dbuf count means that the bonus
2410 * buffer's dnode hold is no longer discounted in
2411 * dnode_move(). The dnode cannot move until after
2412 * the dnode_rele_and_unlock() below.
2417 * Do not reference db after its lock is dropped.
2418 * Another thread may evict it.
2420 mutex_exit(&db
->db_mtx
);
2423 * If the dnode has been freed, evict the bonus
2424 * buffer immediately. The data in the bonus
2425 * buffer is no longer relevant and this prevents
2426 * a stale bonus buffer from being associated
2427 * with this dnode_t should the dnode_t be reused
2428 * prior to being destroyed.
2430 mutex_enter(&dn
->dn_mtx
);
2431 if (dn
->dn_type
== DMU_OT_NONE
||
2432 dn
->dn_free_txg
!= 0) {
2434 * Drop dn_mtx. It is a leaf lock and
2435 * cannot be held when dnode_evict_bonus()
2436 * acquires other locks in order to
2437 * perform the eviction.
2439 * Freed dnodes cannot be reused until the
2440 * last hold is released. Since this bonus
2441 * buffer has a hold, the dnode will remain
2442 * in the free state, even without dn_mtx
2443 * held, until the dnode_rele_and_unlock()
2446 mutex_exit(&dn
->dn_mtx
);
2447 dnode_evict_bonus(dn
);
2448 mutex_enter(&dn
->dn_mtx
);
2450 dnode_rele_and_unlock(dn
, db
);
2451 } else if (db
->db_buf
== NULL
) {
2453 * This is a special case: we never associated this
2454 * dbuf with any data allocated from the ARC.
2456 ASSERT(db
->db_state
== DB_UNCACHED
||
2457 db
->db_state
== DB_NOFILL
);
2459 } else if (arc_released(db
->db_buf
)) {
2460 arc_buf_t
*buf
= db
->db_buf
;
2462 * This dbuf has anonymous data associated with it.
2464 dbuf_clear_data(db
);
2465 VERIFY(arc_buf_remove_ref(buf
, db
));
2468 VERIFY(!arc_buf_remove_ref(db
->db_buf
, db
));
2471 * A dbuf will be eligible for eviction if either the
2472 * 'primarycache' property is set or a duplicate
2473 * copy of this buffer is already cached in the arc.
2475 * In the case of the 'primarycache' a buffer
2476 * is considered for eviction if it matches the
2477 * criteria set in the property.
2479 * To decide if our buffer is considered a
2480 * duplicate, we must call into the arc to determine
2481 * if multiple buffers are referencing the same
2482 * block on-disk. If so, then we simply evict
2485 if (!DBUF_IS_CACHEABLE(db
)) {
2486 if (db
->db_blkptr
!= NULL
&&
2487 !BP_IS_HOLE(db
->db_blkptr
) &&
2488 !BP_IS_EMBEDDED(db
->db_blkptr
)) {
2490 dmu_objset_spa(db
->db_objset
);
2491 blkptr_t bp
= *db
->db_blkptr
;
2493 arc_freed(spa
, &bp
);
2497 } else if (db
->db_objset
->os_evicting
||
2498 arc_buf_eviction_needed(db
->db_buf
)) {
2501 mutex_exit(&db
->db_mtx
);
2505 mutex_exit(&db
->db_mtx
);
2509 #pragma weak dmu_buf_refcount = dbuf_refcount
2511 dbuf_refcount(dmu_buf_impl_t
*db
)
2513 return (refcount_count(&db
->db_holds
));
2517 dmu_buf_replace_user(dmu_buf_t
*db_fake
, dmu_buf_user_t
*old_user
,
2518 dmu_buf_user_t
*new_user
)
2520 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)db_fake
;
2522 mutex_enter(&db
->db_mtx
);
2523 dbuf_verify_user(db
, DBVU_NOT_EVICTING
);
2524 if (db
->db_user
== old_user
)
2525 db
->db_user
= new_user
;
2527 old_user
= db
->db_user
;
2528 dbuf_verify_user(db
, DBVU_NOT_EVICTING
);
2529 mutex_exit(&db
->db_mtx
);
2535 dmu_buf_set_user(dmu_buf_t
*db_fake
, dmu_buf_user_t
*user
)
2537 return (dmu_buf_replace_user(db_fake
, NULL
, user
));
2541 dmu_buf_set_user_ie(dmu_buf_t
*db_fake
, dmu_buf_user_t
*user
)
2543 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)db_fake
;
2545 db
->db_immediate_evict
= TRUE
;
2546 return (dmu_buf_set_user(db_fake
, user
));
2550 dmu_buf_remove_user(dmu_buf_t
*db_fake
, dmu_buf_user_t
*user
)
2552 return (dmu_buf_replace_user(db_fake
, user
, NULL
));
2556 dmu_buf_get_user(dmu_buf_t
*db_fake
)
2558 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)db_fake
;
2560 dbuf_verify_user(db
, DBVU_NOT_EVICTING
);
2561 return (db
->db_user
);
2565 dmu_buf_user_evict_wait()
2567 taskq_wait(dbu_evict_taskq
);
2571 dmu_buf_freeable(dmu_buf_t
*dbuf
)
2573 boolean_t res
= B_FALSE
;
2574 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)dbuf
;
2577 res
= dsl_dataset_block_freeable(db
->db_objset
->os_dsl_dataset
,
2578 db
->db_blkptr
, db
->db_blkptr
->blk_birth
);
2584 dmu_buf_get_blkptr(dmu_buf_t
*db
)
2586 dmu_buf_impl_t
*dbi
= (dmu_buf_impl_t
*)db
;
2587 return (dbi
->db_blkptr
);
2591 dbuf_check_blkptr(dnode_t
*dn
, dmu_buf_impl_t
*db
)
2593 /* ASSERT(dmu_tx_is_syncing(tx) */
2594 ASSERT(MUTEX_HELD(&db
->db_mtx
));
2596 if (db
->db_blkptr
!= NULL
)
2599 if (db
->db_blkid
== DMU_SPILL_BLKID
) {
2600 db
->db_blkptr
= &dn
->dn_phys
->dn_spill
;
2601 BP_ZERO(db
->db_blkptr
);
2604 if (db
->db_level
== dn
->dn_phys
->dn_nlevels
-1) {
2606 * This buffer was allocated at a time when there was
2607 * no available blkptrs from the dnode, or it was
2608 * inappropriate to hook it in (i.e., nlevels mis-match).
2610 ASSERT(db
->db_blkid
< dn
->dn_phys
->dn_nblkptr
);
2611 ASSERT(db
->db_parent
== NULL
);
2612 db
->db_parent
= dn
->dn_dbuf
;
2613 db
->db_blkptr
= &dn
->dn_phys
->dn_blkptr
[db
->db_blkid
];
2616 dmu_buf_impl_t
*parent
= db
->db_parent
;
2617 int epbs
= dn
->dn_phys
->dn_indblkshift
- SPA_BLKPTRSHIFT
;
2619 ASSERT(dn
->dn_phys
->dn_nlevels
> 1);
2620 if (parent
== NULL
) {
2621 mutex_exit(&db
->db_mtx
);
2622 rw_enter(&dn
->dn_struct_rwlock
, RW_READER
);
2623 parent
= dbuf_hold_level(dn
, db
->db_level
+ 1,
2624 db
->db_blkid
>> epbs
, db
);
2625 rw_exit(&dn
->dn_struct_rwlock
);
2626 mutex_enter(&db
->db_mtx
);
2627 db
->db_parent
= parent
;
2629 db
->db_blkptr
= (blkptr_t
*)parent
->db
.db_data
+
2630 (db
->db_blkid
& ((1ULL << epbs
) - 1));
2636 dbuf_sync_indirect(dbuf_dirty_record_t
*dr
, dmu_tx_t
*tx
)
2638 dmu_buf_impl_t
*db
= dr
->dr_dbuf
;
2642 ASSERT(dmu_tx_is_syncing(tx
));
2644 dprintf_dbuf_bp(db
, db
->db_blkptr
, "blkptr=%p", db
->db_blkptr
);
2646 mutex_enter(&db
->db_mtx
);
2648 ASSERT(db
->db_level
> 0);
2651 /* Read the block if it hasn't been read yet. */
2652 if (db
->db_buf
== NULL
) {
2653 mutex_exit(&db
->db_mtx
);
2654 (void) dbuf_read(db
, NULL
, DB_RF_MUST_SUCCEED
);
2655 mutex_enter(&db
->db_mtx
);
2657 ASSERT3U(db
->db_state
, ==, DB_CACHED
);
2658 ASSERT(db
->db_buf
!= NULL
);
2662 /* Indirect block size must match what the dnode thinks it is. */
2663 ASSERT3U(db
->db
.db_size
, ==, 1<<dn
->dn_phys
->dn_indblkshift
);
2664 dbuf_check_blkptr(dn
, db
);
2667 /* Provide the pending dirty record to child dbufs */
2668 db
->db_data_pending
= dr
;
2670 mutex_exit(&db
->db_mtx
);
2671 dbuf_write(dr
, db
->db_buf
, tx
);
2674 mutex_enter(&dr
->dt
.di
.dr_mtx
);
2675 dbuf_sync_list(&dr
->dt
.di
.dr_children
, db
->db_level
- 1, tx
);
2676 ASSERT(list_head(&dr
->dt
.di
.dr_children
) == NULL
);
2677 mutex_exit(&dr
->dt
.di
.dr_mtx
);
2682 dbuf_sync_leaf(dbuf_dirty_record_t
*dr
, dmu_tx_t
*tx
)
2684 arc_buf_t
**datap
= &dr
->dt
.dl
.dr_data
;
2685 dmu_buf_impl_t
*db
= dr
->dr_dbuf
;
2688 uint64_t txg
= tx
->tx_txg
;
2690 ASSERT(dmu_tx_is_syncing(tx
));
2692 dprintf_dbuf_bp(db
, db
->db_blkptr
, "blkptr=%p", db
->db_blkptr
);
2694 mutex_enter(&db
->db_mtx
);
2696 * To be synced, we must be dirtied. But we
2697 * might have been freed after the dirty.
2699 if (db
->db_state
== DB_UNCACHED
) {
2700 /* This buffer has been freed since it was dirtied */
2701 ASSERT(db
->db
.db_data
== NULL
);
2702 } else if (db
->db_state
== DB_FILL
) {
2703 /* This buffer was freed and is now being re-filled */
2704 ASSERT(db
->db
.db_data
!= dr
->dt
.dl
.dr_data
);
2706 ASSERT(db
->db_state
== DB_CACHED
|| db
->db_state
== DB_NOFILL
);
2713 if (db
->db_blkid
== DMU_SPILL_BLKID
) {
2714 mutex_enter(&dn
->dn_mtx
);
2715 dn
->dn_phys
->dn_flags
|= DNODE_FLAG_SPILL_BLKPTR
;
2716 mutex_exit(&dn
->dn_mtx
);
2720 * If this is a bonus buffer, simply copy the bonus data into the
2721 * dnode. It will be written out when the dnode is synced (and it
2722 * will be synced, since it must have been dirty for dbuf_sync to
2725 if (db
->db_blkid
== DMU_BONUS_BLKID
) {
2726 dbuf_dirty_record_t
**drp
;
2728 ASSERT(*datap
!= NULL
);
2729 ASSERT0(db
->db_level
);
2730 ASSERT3U(dn
->dn_phys
->dn_bonuslen
, <=, DN_MAX_BONUSLEN
);
2731 bcopy(*datap
, DN_BONUS(dn
->dn_phys
), dn
->dn_phys
->dn_bonuslen
);
2734 if (*datap
!= db
->db
.db_data
) {
2735 zio_buf_free(*datap
, DN_MAX_BONUSLEN
);
2736 arc_space_return(DN_MAX_BONUSLEN
, ARC_SPACE_OTHER
);
2738 db
->db_data_pending
= NULL
;
2739 drp
= &db
->db_last_dirty
;
2741 drp
= &(*drp
)->dr_next
;
2742 ASSERT(dr
->dr_next
== NULL
);
2743 ASSERT(dr
->dr_dbuf
== db
);
2745 kmem_free(dr
, sizeof (dbuf_dirty_record_t
));
2746 ASSERT(db
->db_dirtycnt
> 0);
2747 db
->db_dirtycnt
-= 1;
2748 dbuf_rele_and_unlock(db
, (void *)(uintptr_t)txg
);
2755 * This function may have dropped the db_mtx lock allowing a dmu_sync
2756 * operation to sneak in. As a result, we need to ensure that we
2757 * don't check the dr_override_state until we have returned from
2758 * dbuf_check_blkptr.
2760 dbuf_check_blkptr(dn
, db
);
2763 * If this buffer is in the middle of an immediate write,
2764 * wait for the synchronous IO to complete.
2766 while (dr
->dt
.dl
.dr_override_state
== DR_IN_DMU_SYNC
) {
2767 ASSERT(dn
->dn_object
!= DMU_META_DNODE_OBJECT
);
2768 cv_wait(&db
->db_changed
, &db
->db_mtx
);
2769 ASSERT(dr
->dt
.dl
.dr_override_state
!= DR_NOT_OVERRIDDEN
);
2772 if (db
->db_state
!= DB_NOFILL
&&
2773 dn
->dn_object
!= DMU_META_DNODE_OBJECT
&&
2774 refcount_count(&db
->db_holds
) > 1 &&
2775 dr
->dt
.dl
.dr_override_state
!= DR_OVERRIDDEN
&&
2776 *datap
== db
->db_buf
) {
2778 * If this buffer is currently "in use" (i.e., there
2779 * are active holds and db_data still references it),
2780 * then make a copy before we start the write so that
2781 * any modifications from the open txg will not leak
2784 * NOTE: this copy does not need to be made for
2785 * objects only modified in the syncing context (e.g.
2786 * DNONE_DNODE blocks).
2788 int blksz
= arc_buf_size(*datap
);
2789 arc_buf_contents_t type
= DBUF_GET_BUFC_TYPE(db
);
2790 *datap
= arc_buf_alloc(os
->os_spa
, blksz
, db
, type
);
2791 bcopy(db
->db
.db_data
, (*datap
)->b_data
, blksz
);
2793 db
->db_data_pending
= dr
;
2795 mutex_exit(&db
->db_mtx
);
2797 dbuf_write(dr
, *datap
, tx
);
2799 ASSERT(!list_link_active(&dr
->dr_dirty_node
));
2800 if (dn
->dn_object
== DMU_META_DNODE_OBJECT
) {
2801 list_insert_tail(&dn
->dn_dirty_records
[txg
&TXG_MASK
], dr
);
2805 * Although zio_nowait() does not "wait for an IO", it does
2806 * initiate the IO. If this is an empty write it seems plausible
2807 * that the IO could actually be completed before the nowait
2808 * returns. We need to DB_DNODE_EXIT() first in case
2809 * zio_nowait() invalidates the dbuf.
2812 zio_nowait(dr
->dr_zio
);
2817 dbuf_sync_list(list_t
*list
, int level
, dmu_tx_t
*tx
)
2819 dbuf_dirty_record_t
*dr
;
2821 while (dr
= list_head(list
)) {
2822 if (dr
->dr_zio
!= NULL
) {
2824 * If we find an already initialized zio then we
2825 * are processing the meta-dnode, and we have finished.
2826 * The dbufs for all dnodes are put back on the list
2827 * during processing, so that we can zio_wait()
2828 * these IOs after initiating all child IOs.
2830 ASSERT3U(dr
->dr_dbuf
->db
.db_object
, ==,
2831 DMU_META_DNODE_OBJECT
);
2834 if (dr
->dr_dbuf
->db_blkid
!= DMU_BONUS_BLKID
&&
2835 dr
->dr_dbuf
->db_blkid
!= DMU_SPILL_BLKID
) {
2836 VERIFY3U(dr
->dr_dbuf
->db_level
, ==, level
);
2838 list_remove(list
, dr
);
2839 if (dr
->dr_dbuf
->db_level
> 0)
2840 dbuf_sync_indirect(dr
, tx
);
2842 dbuf_sync_leaf(dr
, tx
);
2848 dbuf_write_ready(zio_t
*zio
, arc_buf_t
*buf
, void *vdb
)
2850 dmu_buf_impl_t
*db
= vdb
;
2852 blkptr_t
*bp
= zio
->io_bp
;
2853 blkptr_t
*bp_orig
= &zio
->io_bp_orig
;
2854 spa_t
*spa
= zio
->io_spa
;
2859 ASSERT3P(db
->db_blkptr
, ==, bp
);
2863 delta
= bp_get_dsize_sync(spa
, bp
) - bp_get_dsize_sync(spa
, bp_orig
);
2864 dnode_diduse_space(dn
, delta
- zio
->io_prev_space_delta
);
2865 zio
->io_prev_space_delta
= delta
;
2867 if (bp
->blk_birth
!= 0) {
2868 ASSERT((db
->db_blkid
!= DMU_SPILL_BLKID
&&
2869 BP_GET_TYPE(bp
) == dn
->dn_type
) ||
2870 (db
->db_blkid
== DMU_SPILL_BLKID
&&
2871 BP_GET_TYPE(bp
) == dn
->dn_bonustype
) ||
2872 BP_IS_EMBEDDED(bp
));
2873 ASSERT(BP_GET_LEVEL(bp
) == db
->db_level
);
2876 mutex_enter(&db
->db_mtx
);
2879 if (db
->db_blkid
== DMU_SPILL_BLKID
) {
2880 ASSERT(dn
->dn_phys
->dn_flags
& DNODE_FLAG_SPILL_BLKPTR
);
2881 ASSERT(!(BP_IS_HOLE(db
->db_blkptr
)) &&
2882 db
->db_blkptr
== &dn
->dn_phys
->dn_spill
);
2886 if (db
->db_level
== 0) {
2887 mutex_enter(&dn
->dn_mtx
);
2888 if (db
->db_blkid
> dn
->dn_phys
->dn_maxblkid
&&
2889 db
->db_blkid
!= DMU_SPILL_BLKID
)
2890 dn
->dn_phys
->dn_maxblkid
= db
->db_blkid
;
2891 mutex_exit(&dn
->dn_mtx
);
2893 if (dn
->dn_type
== DMU_OT_DNODE
) {
2894 dnode_phys_t
*dnp
= db
->db
.db_data
;
2895 for (i
= db
->db
.db_size
>> DNODE_SHIFT
; i
> 0;
2897 if (dnp
->dn_type
!= DMU_OT_NONE
)
2901 if (BP_IS_HOLE(bp
)) {
2908 blkptr_t
*ibp
= db
->db
.db_data
;
2909 ASSERT3U(db
->db
.db_size
, ==, 1<<dn
->dn_phys
->dn_indblkshift
);
2910 for (i
= db
->db
.db_size
>> SPA_BLKPTRSHIFT
; i
> 0; i
--, ibp
++) {
2911 if (BP_IS_HOLE(ibp
))
2913 fill
+= BP_GET_FILL(ibp
);
2918 if (!BP_IS_EMBEDDED(bp
))
2919 bp
->blk_fill
= fill
;
2921 mutex_exit(&db
->db_mtx
);
2925 * The SPA will call this callback several times for each zio - once
2926 * for every physical child i/o (zio->io_phys_children times). This
2927 * allows the DMU to monitor the progress of each logical i/o. For example,
2928 * there may be 2 copies of an indirect block, or many fragments of a RAID-Z
2929 * block. There may be a long delay before all copies/fragments are completed,
2930 * so this callback allows us to retire dirty space gradually, as the physical
2935 dbuf_write_physdone(zio_t
*zio
, arc_buf_t
*buf
, void *arg
)
2937 dmu_buf_impl_t
*db
= arg
;
2938 objset_t
*os
= db
->db_objset
;
2939 dsl_pool_t
*dp
= dmu_objset_pool(os
);
2940 dbuf_dirty_record_t
*dr
;
2943 dr
= db
->db_data_pending
;
2944 ASSERT3U(dr
->dr_txg
, ==, zio
->io_txg
);
2947 * The callback will be called io_phys_children times. Retire one
2948 * portion of our dirty space each time we are called. Any rounding
2949 * error will be cleaned up by dsl_pool_sync()'s call to
2950 * dsl_pool_undirty_space().
2952 delta
= dr
->dr_accounted
/ zio
->io_phys_children
;
2953 dsl_pool_undirty_space(dp
, delta
, zio
->io_txg
);
2958 dbuf_write_done(zio_t
*zio
, arc_buf_t
*buf
, void *vdb
)
2960 dmu_buf_impl_t
*db
= vdb
;
2961 blkptr_t
*bp_orig
= &zio
->io_bp_orig
;
2962 blkptr_t
*bp
= db
->db_blkptr
;
2963 objset_t
*os
= db
->db_objset
;
2964 dmu_tx_t
*tx
= os
->os_synctx
;
2965 dbuf_dirty_record_t
**drp
, *dr
;
2967 ASSERT0(zio
->io_error
);
2968 ASSERT(db
->db_blkptr
== bp
);
2971 * For nopwrites and rewrites we ensure that the bp matches our
2972 * original and bypass all the accounting.
2974 if (zio
->io_flags
& (ZIO_FLAG_IO_REWRITE
| ZIO_FLAG_NOPWRITE
)) {
2975 ASSERT(BP_EQUAL(bp
, bp_orig
));
2977 dsl_dataset_t
*ds
= os
->os_dsl_dataset
;
2978 (void) dsl_dataset_block_kill(ds
, bp_orig
, tx
, B_TRUE
);
2979 dsl_dataset_block_born(ds
, bp
, tx
);
2982 mutex_enter(&db
->db_mtx
);
2986 drp
= &db
->db_last_dirty
;
2987 while ((dr
= *drp
) != db
->db_data_pending
)
2989 ASSERT(!list_link_active(&dr
->dr_dirty_node
));
2990 ASSERT(dr
->dr_dbuf
== db
);
2991 ASSERT(dr
->dr_next
== NULL
);
2995 if (db
->db_blkid
== DMU_SPILL_BLKID
) {
3000 ASSERT(dn
->dn_phys
->dn_flags
& DNODE_FLAG_SPILL_BLKPTR
);
3001 ASSERT(!(BP_IS_HOLE(db
->db_blkptr
)) &&
3002 db
->db_blkptr
== &dn
->dn_phys
->dn_spill
);
3007 if (db
->db_level
== 0) {
3008 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
3009 ASSERT(dr
->dt
.dl
.dr_override_state
== DR_NOT_OVERRIDDEN
);
3010 if (db
->db_state
!= DB_NOFILL
) {
3011 if (dr
->dt
.dl
.dr_data
!= db
->db_buf
)
3012 VERIFY(arc_buf_remove_ref(dr
->dt
.dl
.dr_data
,
3014 else if (!arc_released(db
->db_buf
))
3015 arc_set_callback(db
->db_buf
, dbuf_do_evict
, db
);
3022 ASSERT(list_head(&dr
->dt
.di
.dr_children
) == NULL
);
3023 ASSERT3U(db
->db
.db_size
, ==, 1 << dn
->dn_phys
->dn_indblkshift
);
3024 if (!BP_IS_HOLE(db
->db_blkptr
)) {
3026 dn
->dn_phys
->dn_indblkshift
- SPA_BLKPTRSHIFT
;
3027 ASSERT3U(db
->db_blkid
, <=,
3028 dn
->dn_phys
->dn_maxblkid
>> (db
->db_level
* epbs
));
3029 ASSERT3U(BP_GET_LSIZE(db
->db_blkptr
), ==,
3031 if (!arc_released(db
->db_buf
))
3032 arc_set_callback(db
->db_buf
, dbuf_do_evict
, db
);
3035 mutex_destroy(&dr
->dt
.di
.dr_mtx
);
3036 list_destroy(&dr
->dt
.di
.dr_children
);
3038 kmem_free(dr
, sizeof (dbuf_dirty_record_t
));
3040 cv_broadcast(&db
->db_changed
);
3041 ASSERT(db
->db_dirtycnt
> 0);
3042 db
->db_dirtycnt
-= 1;
3043 db
->db_data_pending
= NULL
;
3044 dbuf_rele_and_unlock(db
, (void *)(uintptr_t)tx
->tx_txg
);
3048 dbuf_write_nofill_ready(zio_t
*zio
)
3050 dbuf_write_ready(zio
, NULL
, zio
->io_private
);
3054 dbuf_write_nofill_done(zio_t
*zio
)
3056 dbuf_write_done(zio
, NULL
, zio
->io_private
);
3060 dbuf_write_override_ready(zio_t
*zio
)
3062 dbuf_dirty_record_t
*dr
= zio
->io_private
;
3063 dmu_buf_impl_t
*db
= dr
->dr_dbuf
;
3065 dbuf_write_ready(zio
, NULL
, db
);
3069 dbuf_write_override_done(zio_t
*zio
)
3071 dbuf_dirty_record_t
*dr
= zio
->io_private
;
3072 dmu_buf_impl_t
*db
= dr
->dr_dbuf
;
3073 blkptr_t
*obp
= &dr
->dt
.dl
.dr_overridden_by
;
3075 mutex_enter(&db
->db_mtx
);
3076 if (!BP_EQUAL(zio
->io_bp
, obp
)) {
3077 if (!BP_IS_HOLE(obp
))
3078 dsl_free(spa_get_dsl(zio
->io_spa
), zio
->io_txg
, obp
);
3079 arc_release(dr
->dt
.dl
.dr_data
, db
);
3081 mutex_exit(&db
->db_mtx
);
3083 dbuf_write_done(zio
, NULL
, db
);
3086 /* Issue I/O to commit a dirty buffer to disk. */
3088 dbuf_write(dbuf_dirty_record_t
*dr
, arc_buf_t
*data
, dmu_tx_t
*tx
)
3090 dmu_buf_impl_t
*db
= dr
->dr_dbuf
;
3093 dmu_buf_impl_t
*parent
= db
->db_parent
;
3094 uint64_t txg
= tx
->tx_txg
;
3095 zbookmark_phys_t zb
;
3104 if (db
->db_state
!= DB_NOFILL
) {
3105 if (db
->db_level
> 0 || dn
->dn_type
== DMU_OT_DNODE
) {
3107 * Private object buffers are released here rather
3108 * than in dbuf_dirty() since they are only modified
3109 * in the syncing context and we don't want the
3110 * overhead of making multiple copies of the data.
3112 if (BP_IS_HOLE(db
->db_blkptr
)) {
3115 dbuf_release_bp(db
);
3120 if (parent
!= dn
->dn_dbuf
) {
3121 /* Our parent is an indirect block. */
3122 /* We have a dirty parent that has been scheduled for write. */
3123 ASSERT(parent
&& parent
->db_data_pending
);
3124 /* Our parent's buffer is one level closer to the dnode. */
3125 ASSERT(db
->db_level
== parent
->db_level
-1);
3127 * We're about to modify our parent's db_data by modifying
3128 * our block pointer, so the parent must be released.
3130 ASSERT(arc_released(parent
->db_buf
));
3131 zio
= parent
->db_data_pending
->dr_zio
;
3133 /* Our parent is the dnode itself. */
3134 ASSERT((db
->db_level
== dn
->dn_phys
->dn_nlevels
-1 &&
3135 db
->db_blkid
!= DMU_SPILL_BLKID
) ||
3136 (db
->db_blkid
== DMU_SPILL_BLKID
&& db
->db_level
== 0));
3137 if (db
->db_blkid
!= DMU_SPILL_BLKID
)
3138 ASSERT3P(db
->db_blkptr
, ==,
3139 &dn
->dn_phys
->dn_blkptr
[db
->db_blkid
]);
3143 ASSERT(db
->db_level
== 0 || data
== db
->db_buf
);
3144 ASSERT3U(db
->db_blkptr
->blk_birth
, <=, txg
);
3147 SET_BOOKMARK(&zb
, os
->os_dsl_dataset
?
3148 os
->os_dsl_dataset
->ds_object
: DMU_META_OBJSET
,
3149 db
->db
.db_object
, db
->db_level
, db
->db_blkid
);
3151 if (db
->db_blkid
== DMU_SPILL_BLKID
)
3153 wp_flag
|= (db
->db_state
== DB_NOFILL
) ? WP_NOFILL
: 0;
3155 dmu_write_policy(os
, dn
, db
->db_level
, wp_flag
, &zp
);
3158 if (db
->db_level
== 0 &&
3159 dr
->dt
.dl
.dr_override_state
== DR_OVERRIDDEN
) {
3161 * The BP for this block has been provided by open context
3162 * (by dmu_sync() or dmu_buf_write_embedded()).
3164 void *contents
= (data
!= NULL
) ? data
->b_data
: NULL
;
3166 dr
->dr_zio
= zio_write(zio
, os
->os_spa
, txg
,
3167 db
->db_blkptr
, contents
, db
->db
.db_size
, &zp
,
3168 dbuf_write_override_ready
, NULL
, dbuf_write_override_done
,
3169 dr
, ZIO_PRIORITY_ASYNC_WRITE
, ZIO_FLAG_MUSTSUCCEED
, &zb
);
3170 mutex_enter(&db
->db_mtx
);
3171 dr
->dt
.dl
.dr_override_state
= DR_NOT_OVERRIDDEN
;
3172 zio_write_override(dr
->dr_zio
, &dr
->dt
.dl
.dr_overridden_by
,
3173 dr
->dt
.dl
.dr_copies
, dr
->dt
.dl
.dr_nopwrite
);
3174 mutex_exit(&db
->db_mtx
);
3175 } else if (db
->db_state
== DB_NOFILL
) {
3176 ASSERT(zp
.zp_checksum
== ZIO_CHECKSUM_OFF
||
3177 zp
.zp_checksum
== ZIO_CHECKSUM_NOPARITY
);
3178 dr
->dr_zio
= zio_write(zio
, os
->os_spa
, txg
,
3179 db
->db_blkptr
, NULL
, db
->db
.db_size
, &zp
,
3180 dbuf_write_nofill_ready
, NULL
, dbuf_write_nofill_done
, db
,
3181 ZIO_PRIORITY_ASYNC_WRITE
,
3182 ZIO_FLAG_MUSTSUCCEED
| ZIO_FLAG_NODATA
, &zb
);
3184 ASSERT(arc_released(data
));
3185 dr
->dr_zio
= arc_write(zio
, os
->os_spa
, txg
,
3186 db
->db_blkptr
, data
, DBUF_IS_L2CACHEABLE(db
),
3187 DBUF_IS_L2COMPRESSIBLE(db
), &zp
, dbuf_write_ready
,
3188 dbuf_write_physdone
, dbuf_write_done
, db
,
3189 ZIO_PRIORITY_ASYNC_WRITE
, ZIO_FLAG_MUSTSUCCEED
, &zb
);