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) 2013 by Delphix. All rights reserved.
25 * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
28 #include <sys/zfs_context.h>
31 #include <sys/dmu_impl.h>
33 #include <sys/dmu_objset.h>
34 #include <sys/dsl_dataset.h>
35 #include <sys/dsl_dir.h>
36 #include <sys/dmu_tx.h>
39 #include <sys/dmu_zfetch.h>
41 #include <sys/sa_impl.h>
43 struct dbuf_hold_impl_data
{
44 /* Function arguments */
50 dmu_buf_impl_t
**dh_dbp
;
52 dmu_buf_impl_t
*dh_db
;
53 dmu_buf_impl_t
*dh_parent
;
56 dbuf_dirty_record_t
*dh_dr
;
57 arc_buf_contents_t dh_type
;
61 static void __dbuf_hold_impl_init(struct dbuf_hold_impl_data
*dh
,
62 dnode_t
*dn
, uint8_t level
, uint64_t blkid
, int fail_sparse
,
63 void *tag
, dmu_buf_impl_t
**dbp
, int depth
);
64 static int __dbuf_hold_impl(struct dbuf_hold_impl_data
*dh
);
66 static void dbuf_destroy(dmu_buf_impl_t
*db
);
67 static boolean_t
dbuf_undirty(dmu_buf_impl_t
*db
, dmu_tx_t
*tx
);
68 static void dbuf_write(dbuf_dirty_record_t
*dr
, arc_buf_t
*data
, dmu_tx_t
*tx
);
71 * Global data structures and functions for the dbuf cache.
73 static kmem_cache_t
*dbuf_cache
;
77 dbuf_cons(void *vdb
, void *unused
, int kmflag
)
79 dmu_buf_impl_t
*db
= vdb
;
80 bzero(db
, sizeof (dmu_buf_impl_t
));
82 mutex_init(&db
->db_mtx
, NULL
, MUTEX_DEFAULT
, NULL
);
83 cv_init(&db
->db_changed
, NULL
, CV_DEFAULT
, NULL
);
84 refcount_create(&db
->db_holds
);
85 list_link_init(&db
->db_link
);
91 dbuf_dest(void *vdb
, void *unused
)
93 dmu_buf_impl_t
*db
= vdb
;
94 mutex_destroy(&db
->db_mtx
);
95 cv_destroy(&db
->db_changed
);
96 refcount_destroy(&db
->db_holds
);
100 * dbuf hash table routines
102 static dbuf_hash_table_t dbuf_hash_table
;
104 static uint64_t dbuf_hash_count
;
107 dbuf_hash(void *os
, uint64_t obj
, uint8_t lvl
, uint64_t blkid
)
109 uintptr_t osv
= (uintptr_t)os
;
110 uint64_t crc
= -1ULL;
112 ASSERT(zfs_crc64_table
[128] == ZFS_CRC64_POLY
);
113 crc
= (crc
>> 8) ^ zfs_crc64_table
[(crc
^ (lvl
)) & 0xFF];
114 crc
= (crc
>> 8) ^ zfs_crc64_table
[(crc
^ (osv
>> 6)) & 0xFF];
115 crc
= (crc
>> 8) ^ zfs_crc64_table
[(crc
^ (obj
>> 0)) & 0xFF];
116 crc
= (crc
>> 8) ^ zfs_crc64_table
[(crc
^ (obj
>> 8)) & 0xFF];
117 crc
= (crc
>> 8) ^ zfs_crc64_table
[(crc
^ (blkid
>> 0)) & 0xFF];
118 crc
= (crc
>> 8) ^ zfs_crc64_table
[(crc
^ (blkid
>> 8)) & 0xFF];
120 crc
^= (osv
>>14) ^ (obj
>>16) ^ (blkid
>>16);
125 #define DBUF_HASH(os, obj, level, blkid) dbuf_hash(os, obj, level, blkid);
127 #define DBUF_EQUAL(dbuf, os, obj, level, blkid) \
128 ((dbuf)->db.db_object == (obj) && \
129 (dbuf)->db_objset == (os) && \
130 (dbuf)->db_level == (level) && \
131 (dbuf)->db_blkid == (blkid))
134 dbuf_find(dnode_t
*dn
, uint8_t level
, uint64_t blkid
)
136 dbuf_hash_table_t
*h
= &dbuf_hash_table
;
137 objset_t
*os
= dn
->dn_objset
;
144 hv
= DBUF_HASH(os
, obj
, level
, blkid
);
145 idx
= hv
& h
->hash_table_mask
;
147 mutex_enter(DBUF_HASH_MUTEX(h
, idx
));
148 for (db
= h
->hash_table
[idx
]; db
!= NULL
; db
= db
->db_hash_next
) {
149 if (DBUF_EQUAL(db
, os
, obj
, level
, blkid
)) {
150 mutex_enter(&db
->db_mtx
);
151 if (db
->db_state
!= DB_EVICTING
) {
152 mutex_exit(DBUF_HASH_MUTEX(h
, idx
));
155 mutex_exit(&db
->db_mtx
);
158 mutex_exit(DBUF_HASH_MUTEX(h
, idx
));
163 * Insert an entry into the hash table. If there is already an element
164 * equal to elem in the hash table, then the already existing element
165 * will be returned and the new element will not be inserted.
166 * Otherwise returns NULL.
168 static dmu_buf_impl_t
*
169 dbuf_hash_insert(dmu_buf_impl_t
*db
)
171 dbuf_hash_table_t
*h
= &dbuf_hash_table
;
172 objset_t
*os
= db
->db_objset
;
173 uint64_t obj
= db
->db
.db_object
;
174 int level
= db
->db_level
;
175 uint64_t blkid
, hv
, idx
;
178 blkid
= db
->db_blkid
;
179 hv
= DBUF_HASH(os
, obj
, level
, blkid
);
180 idx
= hv
& h
->hash_table_mask
;
182 mutex_enter(DBUF_HASH_MUTEX(h
, idx
));
183 for (dbf
= h
->hash_table
[idx
]; dbf
!= NULL
; dbf
= dbf
->db_hash_next
) {
184 if (DBUF_EQUAL(dbf
, os
, obj
, level
, blkid
)) {
185 mutex_enter(&dbf
->db_mtx
);
186 if (dbf
->db_state
!= DB_EVICTING
) {
187 mutex_exit(DBUF_HASH_MUTEX(h
, idx
));
190 mutex_exit(&dbf
->db_mtx
);
194 mutex_enter(&db
->db_mtx
);
195 db
->db_hash_next
= h
->hash_table
[idx
];
196 h
->hash_table
[idx
] = db
;
197 mutex_exit(DBUF_HASH_MUTEX(h
, idx
));
198 atomic_add_64(&dbuf_hash_count
, 1);
204 * Remove an entry from the hash table. This operation will
205 * fail if there are any existing holds on the db.
208 dbuf_hash_remove(dmu_buf_impl_t
*db
)
210 dbuf_hash_table_t
*h
= &dbuf_hash_table
;
212 dmu_buf_impl_t
*dbf
, **dbp
;
214 hv
= DBUF_HASH(db
->db_objset
, db
->db
.db_object
,
215 db
->db_level
, db
->db_blkid
);
216 idx
= hv
& h
->hash_table_mask
;
219 * We musn't hold db_mtx to maintin lock ordering:
220 * DBUF_HASH_MUTEX > db_mtx.
222 ASSERT(refcount_is_zero(&db
->db_holds
));
223 ASSERT(db
->db_state
== DB_EVICTING
);
224 ASSERT(!MUTEX_HELD(&db
->db_mtx
));
226 mutex_enter(DBUF_HASH_MUTEX(h
, idx
));
227 dbp
= &h
->hash_table
[idx
];
228 while ((dbf
= *dbp
) != db
) {
229 dbp
= &dbf
->db_hash_next
;
232 *dbp
= db
->db_hash_next
;
233 db
->db_hash_next
= NULL
;
234 mutex_exit(DBUF_HASH_MUTEX(h
, idx
));
235 atomic_add_64(&dbuf_hash_count
, -1);
238 static arc_evict_func_t dbuf_do_evict
;
241 dbuf_evict_user(dmu_buf_impl_t
*db
)
243 ASSERT(MUTEX_HELD(&db
->db_mtx
));
245 if (db
->db_level
!= 0 || db
->db_evict_func
== NULL
)
248 if (db
->db_user_data_ptr_ptr
)
249 *db
->db_user_data_ptr_ptr
= db
->db
.db_data
;
250 db
->db_evict_func(&db
->db
, db
->db_user_ptr
);
251 db
->db_user_ptr
= NULL
;
252 db
->db_user_data_ptr_ptr
= NULL
;
253 db
->db_evict_func
= NULL
;
257 dbuf_is_metadata(dmu_buf_impl_t
*db
)
259 if (db
->db_level
> 0) {
262 boolean_t is_metadata
;
265 is_metadata
= DMU_OT_IS_METADATA(DB_DNODE(db
)->dn_type
);
268 return (is_metadata
);
273 dbuf_evict(dmu_buf_impl_t
*db
)
275 ASSERT(MUTEX_HELD(&db
->db_mtx
));
276 ASSERT(db
->db_buf
== NULL
);
277 ASSERT(db
->db_data_pending
== NULL
);
286 uint64_t hsize
= 1ULL << 16;
287 dbuf_hash_table_t
*h
= &dbuf_hash_table
;
291 * The hash table is big enough to fill all of physical memory
292 * with an average 4K block size. The table will take up
293 * totalmem*sizeof(void*)/4K (i.e. 2MB/GB with 8-byte pointers).
295 while (hsize
* 4096 < physmem
* PAGESIZE
)
299 h
->hash_table_mask
= hsize
- 1;
300 #if defined(_KERNEL) && defined(HAVE_SPL)
301 /* Large allocations which do not require contiguous pages
302 * should be using vmem_alloc() in the linux kernel */
303 h
->hash_table
= vmem_zalloc(hsize
* sizeof (void *), KM_PUSHPAGE
);
305 h
->hash_table
= kmem_zalloc(hsize
* sizeof (void *), KM_NOSLEEP
);
307 if (h
->hash_table
== NULL
) {
308 /* XXX - we should really return an error instead of assert */
309 ASSERT(hsize
> (1ULL << 10));
314 dbuf_cache
= kmem_cache_create("dmu_buf_impl_t",
315 sizeof (dmu_buf_impl_t
),
316 0, dbuf_cons
, dbuf_dest
, NULL
, NULL
, NULL
, 0);
318 for (i
= 0; i
< DBUF_MUTEXES
; i
++)
319 mutex_init(&h
->hash_mutexes
[i
], NULL
, MUTEX_DEFAULT
, NULL
);
327 dbuf_hash_table_t
*h
= &dbuf_hash_table
;
330 dbuf_stats_destroy();
332 for (i
= 0; i
< DBUF_MUTEXES
; i
++)
333 mutex_destroy(&h
->hash_mutexes
[i
]);
334 #if defined(_KERNEL) && defined(HAVE_SPL)
335 /* Large allocations which do not require contiguous pages
336 * should be using vmem_free() in the linux kernel */
337 vmem_free(h
->hash_table
, (h
->hash_table_mask
+ 1) * sizeof (void *));
339 kmem_free(h
->hash_table
, (h
->hash_table_mask
+ 1) * sizeof (void *));
341 kmem_cache_destroy(dbuf_cache
);
350 dbuf_verify(dmu_buf_impl_t
*db
)
353 dbuf_dirty_record_t
*dr
;
355 ASSERT(MUTEX_HELD(&db
->db_mtx
));
357 if (!(zfs_flags
& ZFS_DEBUG_DBUF_VERIFY
))
360 ASSERT(db
->db_objset
!= NULL
);
364 ASSERT(db
->db_parent
== NULL
);
365 ASSERT(db
->db_blkptr
== NULL
);
367 ASSERT3U(db
->db
.db_object
, ==, dn
->dn_object
);
368 ASSERT3P(db
->db_objset
, ==, dn
->dn_objset
);
369 ASSERT3U(db
->db_level
, <, dn
->dn_nlevels
);
370 ASSERT(db
->db_blkid
== DMU_BONUS_BLKID
||
371 db
->db_blkid
== DMU_SPILL_BLKID
||
372 !list_is_empty(&dn
->dn_dbufs
));
374 if (db
->db_blkid
== DMU_BONUS_BLKID
) {
376 ASSERT3U(db
->db
.db_size
, >=, dn
->dn_bonuslen
);
377 ASSERT3U(db
->db
.db_offset
, ==, DMU_BONUS_BLKID
);
378 } else if (db
->db_blkid
== DMU_SPILL_BLKID
) {
380 ASSERT3U(db
->db
.db_size
, >=, dn
->dn_bonuslen
);
381 ASSERT0(db
->db
.db_offset
);
383 ASSERT3U(db
->db
.db_offset
, ==, db
->db_blkid
* db
->db
.db_size
);
386 for (dr
= db
->db_data_pending
; dr
!= NULL
; dr
= dr
->dr_next
)
387 ASSERT(dr
->dr_dbuf
== db
);
389 for (dr
= db
->db_last_dirty
; dr
!= NULL
; dr
= dr
->dr_next
)
390 ASSERT(dr
->dr_dbuf
== db
);
393 * We can't assert that db_size matches dn_datablksz because it
394 * can be momentarily different when another thread is doing
397 if (db
->db_level
== 0 && db
->db
.db_object
== DMU_META_DNODE_OBJECT
) {
398 dr
= db
->db_data_pending
;
400 * It should only be modified in syncing context, so
401 * make sure we only have one copy of the data.
403 ASSERT(dr
== NULL
|| dr
->dt
.dl
.dr_data
== db
->db_buf
);
406 /* verify db->db_blkptr */
408 if (db
->db_parent
== dn
->dn_dbuf
) {
409 /* db is pointed to by the dnode */
410 /* ASSERT3U(db->db_blkid, <, dn->dn_nblkptr); */
411 if (DMU_OBJECT_IS_SPECIAL(db
->db
.db_object
))
412 ASSERT(db
->db_parent
== NULL
);
414 ASSERT(db
->db_parent
!= NULL
);
415 if (db
->db_blkid
!= DMU_SPILL_BLKID
)
416 ASSERT3P(db
->db_blkptr
, ==,
417 &dn
->dn_phys
->dn_blkptr
[db
->db_blkid
]);
419 /* db is pointed to by an indirect block */
420 ASSERTV(int epb
= db
->db_parent
->db
.db_size
>>
422 ASSERT3U(db
->db_parent
->db_level
, ==, db
->db_level
+1);
423 ASSERT3U(db
->db_parent
->db
.db_object
, ==,
426 * dnode_grow_indblksz() can make this fail if we don't
427 * have the struct_rwlock. XXX indblksz no longer
428 * grows. safe to do this now?
430 if (RW_WRITE_HELD(&dn
->dn_struct_rwlock
)) {
431 ASSERT3P(db
->db_blkptr
, ==,
432 ((blkptr_t
*)db
->db_parent
->db
.db_data
+
433 db
->db_blkid
% epb
));
437 if ((db
->db_blkptr
== NULL
|| BP_IS_HOLE(db
->db_blkptr
)) &&
438 (db
->db_buf
== NULL
|| db
->db_buf
->b_data
) &&
439 db
->db
.db_data
&& db
->db_blkid
!= DMU_BONUS_BLKID
&&
440 db
->db_state
!= DB_FILL
&& !dn
->dn_free_txg
) {
442 * If the blkptr isn't set but they have nonzero data,
443 * it had better be dirty, otherwise we'll lose that
444 * data when we evict this buffer.
446 if (db
->db_dirtycnt
== 0) {
447 ASSERTV(uint64_t *buf
= db
->db
.db_data
);
450 for (i
= 0; i
< db
->db
.db_size
>> 3; i
++) {
460 dbuf_update_data(dmu_buf_impl_t
*db
)
462 ASSERT(MUTEX_HELD(&db
->db_mtx
));
463 if (db
->db_level
== 0 && db
->db_user_data_ptr_ptr
) {
464 ASSERT(!refcount_is_zero(&db
->db_holds
));
465 *db
->db_user_data_ptr_ptr
= db
->db
.db_data
;
470 dbuf_set_data(dmu_buf_impl_t
*db
, arc_buf_t
*buf
)
472 ASSERT(MUTEX_HELD(&db
->db_mtx
));
473 ASSERT(db
->db_buf
== NULL
|| !arc_has_callback(db
->db_buf
));
476 ASSERT(buf
->b_data
!= NULL
);
477 db
->db
.db_data
= buf
->b_data
;
478 if (!arc_released(buf
))
479 arc_set_callback(buf
, dbuf_do_evict
, db
);
480 dbuf_update_data(db
);
483 db
->db
.db_data
= NULL
;
484 if (db
->db_state
!= DB_NOFILL
)
485 db
->db_state
= DB_UNCACHED
;
490 * Loan out an arc_buf for read. Return the loaned arc_buf.
493 dbuf_loan_arcbuf(dmu_buf_impl_t
*db
)
497 mutex_enter(&db
->db_mtx
);
498 if (arc_released(db
->db_buf
) || refcount_count(&db
->db_holds
) > 1) {
499 int blksz
= db
->db
.db_size
;
502 mutex_exit(&db
->db_mtx
);
503 DB_GET_SPA(&spa
, db
);
504 abuf
= arc_loan_buf(spa
, blksz
);
505 bcopy(db
->db
.db_data
, abuf
->b_data
, blksz
);
508 arc_loan_inuse_buf(abuf
, db
);
509 dbuf_set_data(db
, NULL
);
510 mutex_exit(&db
->db_mtx
);
516 dbuf_whichblock(dnode_t
*dn
, uint64_t offset
)
518 if (dn
->dn_datablkshift
) {
519 return (offset
>> dn
->dn_datablkshift
);
521 ASSERT3U(offset
, <, dn
->dn_datablksz
);
527 dbuf_read_done(zio_t
*zio
, arc_buf_t
*buf
, void *vdb
)
529 dmu_buf_impl_t
*db
= vdb
;
531 mutex_enter(&db
->db_mtx
);
532 ASSERT3U(db
->db_state
, ==, DB_READ
);
534 * All reads are synchronous, so we must have a hold on the dbuf
536 ASSERT(refcount_count(&db
->db_holds
) > 0);
537 ASSERT(db
->db_buf
== NULL
);
538 ASSERT(db
->db
.db_data
== NULL
);
539 if (db
->db_level
== 0 && db
->db_freed_in_flight
) {
540 /* we were freed in flight; disregard any error */
541 arc_release(buf
, db
);
542 bzero(buf
->b_data
, db
->db
.db_size
);
544 db
->db_freed_in_flight
= FALSE
;
545 dbuf_set_data(db
, buf
);
546 db
->db_state
= DB_CACHED
;
547 } else if (zio
== NULL
|| zio
->io_error
== 0) {
548 dbuf_set_data(db
, buf
);
549 db
->db_state
= DB_CACHED
;
551 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
552 ASSERT3P(db
->db_buf
, ==, NULL
);
553 VERIFY(arc_buf_remove_ref(buf
, db
));
554 db
->db_state
= DB_UNCACHED
;
556 cv_broadcast(&db
->db_changed
);
557 dbuf_rele_and_unlock(db
, NULL
);
561 dbuf_read_impl(dmu_buf_impl_t
*db
, zio_t
*zio
, uint32_t *flags
)
566 uint32_t aflags
= ARC_NOWAIT
;
570 ASSERT(!refcount_is_zero(&db
->db_holds
));
571 /* We need the struct_rwlock to prevent db_blkptr from changing. */
572 ASSERT(RW_LOCK_HELD(&dn
->dn_struct_rwlock
));
573 ASSERT(MUTEX_HELD(&db
->db_mtx
));
574 ASSERT(db
->db_state
== DB_UNCACHED
);
575 ASSERT(db
->db_buf
== NULL
);
577 if (db
->db_blkid
== DMU_BONUS_BLKID
) {
578 int bonuslen
= MIN(dn
->dn_bonuslen
, dn
->dn_phys
->dn_bonuslen
);
580 ASSERT3U(bonuslen
, <=, db
->db
.db_size
);
581 db
->db
.db_data
= zio_buf_alloc(DN_MAX_BONUSLEN
);
582 arc_space_consume(DN_MAX_BONUSLEN
, ARC_SPACE_OTHER
);
583 if (bonuslen
< DN_MAX_BONUSLEN
)
584 bzero(db
->db
.db_data
, DN_MAX_BONUSLEN
);
586 bcopy(DN_BONUS(dn
->dn_phys
), db
->db
.db_data
, bonuslen
);
588 dbuf_update_data(db
);
589 db
->db_state
= DB_CACHED
;
590 mutex_exit(&db
->db_mtx
);
595 * Recheck BP_IS_HOLE() after dnode_block_freed() in case dnode_sync()
596 * processes the delete record and clears the bp while we are waiting
597 * for the dn_mtx (resulting in a "no" from block_freed).
599 if (db
->db_blkptr
== NULL
|| BP_IS_HOLE(db
->db_blkptr
) ||
600 (db
->db_level
== 0 && (dnode_block_freed(dn
, db
->db_blkid
) ||
601 BP_IS_HOLE(db
->db_blkptr
)))) {
602 arc_buf_contents_t type
= DBUF_GET_BUFC_TYPE(db
);
604 dbuf_set_data(db
, arc_buf_alloc(dn
->dn_objset
->os_spa
,
605 db
->db
.db_size
, db
, type
));
607 bzero(db
->db
.db_data
, db
->db
.db_size
);
608 db
->db_state
= DB_CACHED
;
609 *flags
|= DB_RF_CACHED
;
610 mutex_exit(&db
->db_mtx
);
614 spa
= dn
->dn_objset
->os_spa
;
617 db
->db_state
= DB_READ
;
618 mutex_exit(&db
->db_mtx
);
620 if (DBUF_IS_L2CACHEABLE(db
))
621 aflags
|= ARC_L2CACHE
;
622 if (DBUF_IS_L2COMPRESSIBLE(db
))
623 aflags
|= ARC_L2COMPRESS
;
625 SET_BOOKMARK(&zb
, db
->db_objset
->os_dsl_dataset
?
626 db
->db_objset
->os_dsl_dataset
->ds_object
: DMU_META_OBJSET
,
627 db
->db
.db_object
, db
->db_level
, db
->db_blkid
);
629 dbuf_add_ref(db
, NULL
);
631 (void) arc_read(zio
, spa
, db
->db_blkptr
,
632 dbuf_read_done
, db
, ZIO_PRIORITY_SYNC_READ
,
633 (*flags
& DB_RF_CANFAIL
) ? ZIO_FLAG_CANFAIL
: ZIO_FLAG_MUSTSUCCEED
,
635 if (aflags
& ARC_CACHED
)
636 *flags
|= DB_RF_CACHED
;
640 dbuf_read(dmu_buf_impl_t
*db
, zio_t
*zio
, uint32_t flags
)
643 int havepzio
= (zio
!= NULL
);
648 * We don't have to hold the mutex to check db_state because it
649 * can't be freed while we have a hold on the buffer.
651 ASSERT(!refcount_is_zero(&db
->db_holds
));
653 if (db
->db_state
== DB_NOFILL
)
654 return (SET_ERROR(EIO
));
658 if ((flags
& DB_RF_HAVESTRUCT
) == 0)
659 rw_enter(&dn
->dn_struct_rwlock
, RW_READER
);
661 prefetch
= db
->db_level
== 0 && db
->db_blkid
!= DMU_BONUS_BLKID
&&
662 (flags
& DB_RF_NOPREFETCH
) == 0 && dn
!= NULL
&&
663 DBUF_IS_CACHEABLE(db
);
665 mutex_enter(&db
->db_mtx
);
666 if (db
->db_state
== DB_CACHED
) {
667 mutex_exit(&db
->db_mtx
);
669 dmu_zfetch(&dn
->dn_zfetch
, db
->db
.db_offset
,
670 db
->db
.db_size
, TRUE
);
671 if ((flags
& DB_RF_HAVESTRUCT
) == 0)
672 rw_exit(&dn
->dn_struct_rwlock
);
674 } else if (db
->db_state
== DB_UNCACHED
) {
675 spa_t
*spa
= dn
->dn_objset
->os_spa
;
678 zio
= zio_root(spa
, NULL
, NULL
, ZIO_FLAG_CANFAIL
);
679 dbuf_read_impl(db
, zio
, &flags
);
681 /* dbuf_read_impl has dropped db_mtx for us */
684 dmu_zfetch(&dn
->dn_zfetch
, db
->db
.db_offset
,
685 db
->db
.db_size
, flags
& DB_RF_CACHED
);
687 if ((flags
& DB_RF_HAVESTRUCT
) == 0)
688 rw_exit(&dn
->dn_struct_rwlock
);
695 * Another reader came in while the dbuf was in flight
696 * between UNCACHED and CACHED. Either a writer will finish
697 * writing the buffer (sending the dbuf to CACHED) or the
698 * first reader's request will reach the read_done callback
699 * and send the dbuf to CACHED. Otherwise, a failure
700 * occurred and the dbuf went to UNCACHED.
702 mutex_exit(&db
->db_mtx
);
704 dmu_zfetch(&dn
->dn_zfetch
, db
->db
.db_offset
,
705 db
->db
.db_size
, TRUE
);
706 if ((flags
& DB_RF_HAVESTRUCT
) == 0)
707 rw_exit(&dn
->dn_struct_rwlock
);
710 /* Skip the wait per the caller's request. */
711 mutex_enter(&db
->db_mtx
);
712 if ((flags
& DB_RF_NEVERWAIT
) == 0) {
713 while (db
->db_state
== DB_READ
||
714 db
->db_state
== DB_FILL
) {
715 ASSERT(db
->db_state
== DB_READ
||
716 (flags
& DB_RF_HAVESTRUCT
) == 0);
717 cv_wait(&db
->db_changed
, &db
->db_mtx
);
719 if (db
->db_state
== DB_UNCACHED
)
720 err
= SET_ERROR(EIO
);
722 mutex_exit(&db
->db_mtx
);
725 ASSERT(err
|| havepzio
|| db
->db_state
== DB_CACHED
);
730 dbuf_noread(dmu_buf_impl_t
*db
)
732 ASSERT(!refcount_is_zero(&db
->db_holds
));
733 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
734 mutex_enter(&db
->db_mtx
);
735 while (db
->db_state
== DB_READ
|| db
->db_state
== DB_FILL
)
736 cv_wait(&db
->db_changed
, &db
->db_mtx
);
737 if (db
->db_state
== DB_UNCACHED
) {
738 arc_buf_contents_t type
= DBUF_GET_BUFC_TYPE(db
);
741 ASSERT(db
->db_buf
== NULL
);
742 ASSERT(db
->db
.db_data
== NULL
);
743 DB_GET_SPA(&spa
, db
);
744 dbuf_set_data(db
, arc_buf_alloc(spa
, db
->db
.db_size
, db
, type
));
745 db
->db_state
= DB_FILL
;
746 } else if (db
->db_state
== DB_NOFILL
) {
747 dbuf_set_data(db
, NULL
);
749 ASSERT3U(db
->db_state
, ==, DB_CACHED
);
751 mutex_exit(&db
->db_mtx
);
755 * This is our just-in-time copy function. It makes a copy of
756 * buffers, that have been modified in a previous transaction
757 * group, before we modify them in the current active group.
759 * This function is used in two places: when we are dirtying a
760 * buffer for the first time in a txg, and when we are freeing
761 * a range in a dnode that includes this buffer.
763 * Note that when we are called from dbuf_free_range() we do
764 * not put a hold on the buffer, we just traverse the active
765 * dbuf list for the dnode.
768 dbuf_fix_old_data(dmu_buf_impl_t
*db
, uint64_t txg
)
770 dbuf_dirty_record_t
*dr
= db
->db_last_dirty
;
772 ASSERT(MUTEX_HELD(&db
->db_mtx
));
773 ASSERT(db
->db
.db_data
!= NULL
);
774 ASSERT(db
->db_level
== 0);
775 ASSERT(db
->db
.db_object
!= DMU_META_DNODE_OBJECT
);
778 (dr
->dt
.dl
.dr_data
!=
779 ((db
->db_blkid
== DMU_BONUS_BLKID
) ? db
->db
.db_data
: db
->db_buf
)))
783 * If the last dirty record for this dbuf has not yet synced
784 * and its referencing the dbuf data, either:
785 * reset the reference to point to a new copy,
786 * or (if there a no active holders)
787 * just null out the current db_data pointer.
789 ASSERT(dr
->dr_txg
>= txg
- 2);
790 if (db
->db_blkid
== DMU_BONUS_BLKID
) {
791 /* Note that the data bufs here are zio_bufs */
792 dr
->dt
.dl
.dr_data
= zio_buf_alloc(DN_MAX_BONUSLEN
);
793 arc_space_consume(DN_MAX_BONUSLEN
, ARC_SPACE_OTHER
);
794 bcopy(db
->db
.db_data
, dr
->dt
.dl
.dr_data
, DN_MAX_BONUSLEN
);
795 } else if (refcount_count(&db
->db_holds
) > db
->db_dirtycnt
) {
796 int size
= db
->db
.db_size
;
797 arc_buf_contents_t type
= DBUF_GET_BUFC_TYPE(db
);
800 DB_GET_SPA(&spa
, db
);
801 dr
->dt
.dl
.dr_data
= arc_buf_alloc(spa
, size
, db
, type
);
802 bcopy(db
->db
.db_data
, dr
->dt
.dl
.dr_data
->b_data
, size
);
804 dbuf_set_data(db
, NULL
);
809 dbuf_unoverride(dbuf_dirty_record_t
*dr
)
811 dmu_buf_impl_t
*db
= dr
->dr_dbuf
;
812 blkptr_t
*bp
= &dr
->dt
.dl
.dr_overridden_by
;
813 uint64_t txg
= dr
->dr_txg
;
815 ASSERT(MUTEX_HELD(&db
->db_mtx
));
816 ASSERT(dr
->dt
.dl
.dr_override_state
!= DR_IN_DMU_SYNC
);
817 ASSERT(db
->db_level
== 0);
819 if (db
->db_blkid
== DMU_BONUS_BLKID
||
820 dr
->dt
.dl
.dr_override_state
== DR_NOT_OVERRIDDEN
)
823 ASSERT(db
->db_data_pending
!= dr
);
825 /* free this block */
826 if (!BP_IS_HOLE(bp
) && !dr
->dt
.dl
.dr_nopwrite
) {
829 DB_GET_SPA(&spa
, db
);
830 zio_free(spa
, txg
, bp
);
832 dr
->dt
.dl
.dr_override_state
= DR_NOT_OVERRIDDEN
;
833 dr
->dt
.dl
.dr_nopwrite
= B_FALSE
;
836 * Release the already-written buffer, so we leave it in
837 * a consistent dirty state. Note that all callers are
838 * modifying the buffer, so they will immediately do
839 * another (redundant) arc_release(). Therefore, leave
840 * the buf thawed to save the effort of freezing &
841 * immediately re-thawing it.
843 arc_release(dr
->dt
.dl
.dr_data
, db
);
847 * Evict (if its unreferenced) or clear (if its referenced) any level-0
848 * data blocks in the free range, so that any future readers will find
849 * empty blocks. Also, if we happen accross any level-1 dbufs in the
850 * range that have not already been marked dirty, mark them dirty so
851 * they stay in memory.
854 dbuf_free_range(dnode_t
*dn
, uint64_t start
, uint64_t end
, dmu_tx_t
*tx
)
856 dmu_buf_impl_t
*db
, *db_next
;
857 uint64_t txg
= tx
->tx_txg
;
858 int epbs
= dn
->dn_indblkshift
- SPA_BLKPTRSHIFT
;
859 uint64_t first_l1
= start
>> epbs
;
860 uint64_t last_l1
= end
>> epbs
;
862 if (end
> dn
->dn_maxblkid
&& (end
!= DMU_SPILL_BLKID
)) {
863 end
= dn
->dn_maxblkid
;
864 last_l1
= end
>> epbs
;
866 dprintf_dnode(dn
, "start=%llu end=%llu\n", start
, end
);
867 mutex_enter(&dn
->dn_dbufs_mtx
);
868 for (db
= list_head(&dn
->dn_dbufs
); db
; db
= db_next
) {
869 db_next
= list_next(&dn
->dn_dbufs
, db
);
870 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
872 if (db
->db_level
== 1 &&
873 db
->db_blkid
>= first_l1
&& db
->db_blkid
<= last_l1
) {
874 mutex_enter(&db
->db_mtx
);
875 if (db
->db_last_dirty
&&
876 db
->db_last_dirty
->dr_txg
< txg
) {
877 dbuf_add_ref(db
, FTAG
);
878 mutex_exit(&db
->db_mtx
);
879 dbuf_will_dirty(db
, tx
);
882 mutex_exit(&db
->db_mtx
);
886 if (db
->db_level
!= 0)
888 dprintf_dbuf(db
, "found buf %s\n", "");
889 if (db
->db_blkid
< start
|| db
->db_blkid
> end
)
892 /* found a level 0 buffer in the range */
893 mutex_enter(&db
->db_mtx
);
894 if (dbuf_undirty(db
, tx
)) {
895 /* mutex has been dropped and dbuf destroyed */
899 if (db
->db_state
== DB_UNCACHED
||
900 db
->db_state
== DB_NOFILL
||
901 db
->db_state
== DB_EVICTING
) {
902 ASSERT(db
->db
.db_data
== NULL
);
903 mutex_exit(&db
->db_mtx
);
906 if (db
->db_state
== DB_READ
|| db
->db_state
== DB_FILL
) {
907 /* will be handled in dbuf_read_done or dbuf_rele */
908 db
->db_freed_in_flight
= TRUE
;
909 mutex_exit(&db
->db_mtx
);
912 if (refcount_count(&db
->db_holds
) == 0) {
917 /* The dbuf is referenced */
919 if (db
->db_last_dirty
!= NULL
) {
920 dbuf_dirty_record_t
*dr
= db
->db_last_dirty
;
922 if (dr
->dr_txg
== txg
) {
924 * This buffer is "in-use", re-adjust the file
925 * size to reflect that this buffer may
926 * contain new data when we sync.
928 if (db
->db_blkid
!= DMU_SPILL_BLKID
&&
929 db
->db_blkid
> dn
->dn_maxblkid
)
930 dn
->dn_maxblkid
= db
->db_blkid
;
934 * This dbuf is not dirty in the open context.
935 * Either uncache it (if its not referenced in
936 * the open context) or reset its contents to
939 dbuf_fix_old_data(db
, txg
);
942 /* clear the contents if its cached */
943 if (db
->db_state
== DB_CACHED
) {
944 ASSERT(db
->db
.db_data
!= NULL
);
945 arc_release(db
->db_buf
, db
);
946 bzero(db
->db
.db_data
, db
->db
.db_size
);
947 arc_buf_freeze(db
->db_buf
);
950 mutex_exit(&db
->db_mtx
);
952 mutex_exit(&dn
->dn_dbufs_mtx
);
956 dbuf_block_freeable(dmu_buf_impl_t
*db
)
958 dsl_dataset_t
*ds
= db
->db_objset
->os_dsl_dataset
;
959 uint64_t birth_txg
= 0;
962 * We don't need any locking to protect db_blkptr:
963 * If it's syncing, then db_last_dirty will be set
964 * so we'll ignore db_blkptr.
966 ASSERT(MUTEX_HELD(&db
->db_mtx
));
967 if (db
->db_last_dirty
)
968 birth_txg
= db
->db_last_dirty
->dr_txg
;
969 else if (db
->db_blkptr
)
970 birth_txg
= db
->db_blkptr
->blk_birth
;
973 * If we don't exist or are in a snapshot, we can't be freed.
974 * Don't pass the bp to dsl_dataset_block_freeable() since we
975 * are holding the db_mtx lock and might deadlock if we are
976 * prefetching a dedup-ed block.
979 return (ds
== NULL
||
980 dsl_dataset_block_freeable(ds
, NULL
, birth_txg
));
986 dbuf_new_size(dmu_buf_impl_t
*db
, int size
, dmu_tx_t
*tx
)
988 arc_buf_t
*buf
, *obuf
;
989 int osize
= db
->db
.db_size
;
990 arc_buf_contents_t type
= DBUF_GET_BUFC_TYPE(db
);
993 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
998 /* XXX does *this* func really need the lock? */
999 ASSERT(RW_WRITE_HELD(&dn
->dn_struct_rwlock
));
1002 * This call to dbuf_will_dirty() with the dn_struct_rwlock held
1003 * is OK, because there can be no other references to the db
1004 * when we are changing its size, so no concurrent DB_FILL can
1008 * XXX we should be doing a dbuf_read, checking the return
1009 * value and returning that up to our callers
1011 dbuf_will_dirty(db
, tx
);
1013 /* create the data buffer for the new block */
1014 buf
= arc_buf_alloc(dn
->dn_objset
->os_spa
, size
, db
, type
);
1016 /* copy old block data to the new block */
1018 bcopy(obuf
->b_data
, buf
->b_data
, MIN(osize
, size
));
1019 /* zero the remainder */
1021 bzero((uint8_t *)buf
->b_data
+ osize
, size
- osize
);
1023 mutex_enter(&db
->db_mtx
);
1024 dbuf_set_data(db
, buf
);
1025 VERIFY(arc_buf_remove_ref(obuf
, db
));
1026 db
->db
.db_size
= size
;
1028 if (db
->db_level
== 0) {
1029 ASSERT3U(db
->db_last_dirty
->dr_txg
, ==, tx
->tx_txg
);
1030 db
->db_last_dirty
->dt
.dl
.dr_data
= buf
;
1032 mutex_exit(&db
->db_mtx
);
1034 dnode_willuse_space(dn
, size
-osize
, tx
);
1039 dbuf_release_bp(dmu_buf_impl_t
*db
)
1043 DB_GET_OBJSET(&os
, db
);
1044 ASSERT(dsl_pool_sync_context(dmu_objset_pool(os
)));
1045 ASSERT(arc_released(os
->os_phys_buf
) ||
1046 list_link_active(&os
->os_dsl_dataset
->ds_synced_link
));
1047 ASSERT(db
->db_parent
== NULL
|| arc_released(db
->db_parent
->db_buf
));
1049 (void) arc_release(db
->db_buf
, db
);
1052 dbuf_dirty_record_t
*
1053 dbuf_dirty(dmu_buf_impl_t
*db
, dmu_tx_t
*tx
)
1057 dbuf_dirty_record_t
**drp
, *dr
;
1058 int drop_struct_lock
= FALSE
;
1059 boolean_t do_free_accounting
= B_FALSE
;
1060 int txgoff
= tx
->tx_txg
& TXG_MASK
;
1062 ASSERT(tx
->tx_txg
!= 0);
1063 ASSERT(!refcount_is_zero(&db
->db_holds
));
1064 DMU_TX_DIRTY_BUF(tx
, db
);
1069 * Shouldn't dirty a regular buffer in syncing context. Private
1070 * objects may be dirtied in syncing context, but only if they
1071 * were already pre-dirtied in open context.
1073 ASSERT(!dmu_tx_is_syncing(tx
) ||
1074 BP_IS_HOLE(dn
->dn_objset
->os_rootbp
) ||
1075 DMU_OBJECT_IS_SPECIAL(dn
->dn_object
) ||
1076 dn
->dn_objset
->os_dsl_dataset
== NULL
);
1078 * We make this assert for private objects as well, but after we
1079 * check if we're already dirty. They are allowed to re-dirty
1080 * in syncing context.
1082 ASSERT(dn
->dn_object
== DMU_META_DNODE_OBJECT
||
1083 dn
->dn_dirtyctx
== DN_UNDIRTIED
|| dn
->dn_dirtyctx
==
1084 (dmu_tx_is_syncing(tx
) ? DN_DIRTY_SYNC
: DN_DIRTY_OPEN
));
1086 mutex_enter(&db
->db_mtx
);
1088 * XXX make this true for indirects too? The problem is that
1089 * transactions created with dmu_tx_create_assigned() from
1090 * syncing context don't bother holding ahead.
1092 ASSERT(db
->db_level
!= 0 ||
1093 db
->db_state
== DB_CACHED
|| db
->db_state
== DB_FILL
||
1094 db
->db_state
== DB_NOFILL
);
1096 mutex_enter(&dn
->dn_mtx
);
1098 * Don't set dirtyctx to SYNC if we're just modifying this as we
1099 * initialize the objset.
1101 if (dn
->dn_dirtyctx
== DN_UNDIRTIED
&&
1102 !BP_IS_HOLE(dn
->dn_objset
->os_rootbp
)) {
1104 (dmu_tx_is_syncing(tx
) ? DN_DIRTY_SYNC
: DN_DIRTY_OPEN
);
1105 ASSERT(dn
->dn_dirtyctx_firstset
== NULL
);
1106 dn
->dn_dirtyctx_firstset
= kmem_alloc(1, KM_PUSHPAGE
);
1108 mutex_exit(&dn
->dn_mtx
);
1110 if (db
->db_blkid
== DMU_SPILL_BLKID
)
1111 dn
->dn_have_spill
= B_TRUE
;
1114 * If this buffer is already dirty, we're done.
1116 drp
= &db
->db_last_dirty
;
1117 ASSERT(*drp
== NULL
|| (*drp
)->dr_txg
<= tx
->tx_txg
||
1118 db
->db
.db_object
== DMU_META_DNODE_OBJECT
);
1119 while ((dr
= *drp
) != NULL
&& dr
->dr_txg
> tx
->tx_txg
)
1121 if (dr
&& dr
->dr_txg
== tx
->tx_txg
) {
1124 if (db
->db_level
== 0 && db
->db_blkid
!= DMU_BONUS_BLKID
) {
1126 * If this buffer has already been written out,
1127 * we now need to reset its state.
1129 dbuf_unoverride(dr
);
1130 if (db
->db
.db_object
!= DMU_META_DNODE_OBJECT
&&
1131 db
->db_state
!= DB_NOFILL
)
1132 arc_buf_thaw(db
->db_buf
);
1134 mutex_exit(&db
->db_mtx
);
1139 * Only valid if not already dirty.
1141 ASSERT(dn
->dn_object
== 0 ||
1142 dn
->dn_dirtyctx
== DN_UNDIRTIED
|| dn
->dn_dirtyctx
==
1143 (dmu_tx_is_syncing(tx
) ? DN_DIRTY_SYNC
: DN_DIRTY_OPEN
));
1145 ASSERT3U(dn
->dn_nlevels
, >, db
->db_level
);
1146 ASSERT((dn
->dn_phys
->dn_nlevels
== 0 && db
->db_level
== 0) ||
1147 dn
->dn_phys
->dn_nlevels
> db
->db_level
||
1148 dn
->dn_next_nlevels
[txgoff
] > db
->db_level
||
1149 dn
->dn_next_nlevels
[(tx
->tx_txg
-1) & TXG_MASK
] > db
->db_level
||
1150 dn
->dn_next_nlevels
[(tx
->tx_txg
-2) & TXG_MASK
] > db
->db_level
);
1153 * We should only be dirtying in syncing context if it's the
1154 * mos or we're initializing the os or it's a special object.
1155 * However, we are allowed to dirty in syncing context provided
1156 * we already dirtied it in open context. Hence we must make
1157 * this assertion only if we're not already dirty.
1160 ASSERT(!dmu_tx_is_syncing(tx
) || DMU_OBJECT_IS_SPECIAL(dn
->dn_object
) ||
1161 os
->os_dsl_dataset
== NULL
|| BP_IS_HOLE(os
->os_rootbp
));
1162 ASSERT(db
->db
.db_size
!= 0);
1164 dprintf_dbuf(db
, "size=%llx\n", (u_longlong_t
)db
->db
.db_size
);
1166 if (db
->db_blkid
!= DMU_BONUS_BLKID
) {
1168 * Update the accounting.
1169 * Note: we delay "free accounting" until after we drop
1170 * the db_mtx. This keeps us from grabbing other locks
1171 * (and possibly deadlocking) in bp_get_dsize() while
1172 * also holding the db_mtx.
1174 dnode_willuse_space(dn
, db
->db
.db_size
, tx
);
1175 do_free_accounting
= dbuf_block_freeable(db
);
1179 * If this buffer is dirty in an old transaction group we need
1180 * to make a copy of it so that the changes we make in this
1181 * transaction group won't leak out when we sync the older txg.
1183 dr
= kmem_zalloc(sizeof (dbuf_dirty_record_t
), KM_PUSHPAGE
);
1184 list_link_init(&dr
->dr_dirty_node
);
1185 if (db
->db_level
== 0) {
1186 void *data_old
= db
->db_buf
;
1188 if (db
->db_state
!= DB_NOFILL
) {
1189 if (db
->db_blkid
== DMU_BONUS_BLKID
) {
1190 dbuf_fix_old_data(db
, tx
->tx_txg
);
1191 data_old
= db
->db
.db_data
;
1192 } else if (db
->db
.db_object
!= DMU_META_DNODE_OBJECT
) {
1194 * Release the data buffer from the cache so
1195 * that we can modify it without impacting
1196 * possible other users of this cached data
1197 * block. Note that indirect blocks and
1198 * private objects are not released until the
1199 * syncing state (since they are only modified
1202 arc_release(db
->db_buf
, db
);
1203 dbuf_fix_old_data(db
, tx
->tx_txg
);
1204 data_old
= db
->db_buf
;
1206 ASSERT(data_old
!= NULL
);
1208 dr
->dt
.dl
.dr_data
= data_old
;
1210 mutex_init(&dr
->dt
.di
.dr_mtx
, NULL
, MUTEX_DEFAULT
, NULL
);
1211 list_create(&dr
->dt
.di
.dr_children
,
1212 sizeof (dbuf_dirty_record_t
),
1213 offsetof(dbuf_dirty_record_t
, dr_dirty_node
));
1216 dr
->dr_txg
= tx
->tx_txg
;
1221 * We could have been freed_in_flight between the dbuf_noread
1222 * and dbuf_dirty. We win, as though the dbuf_noread() had
1223 * happened after the free.
1225 if (db
->db_level
== 0 && db
->db_blkid
!= DMU_BONUS_BLKID
&&
1226 db
->db_blkid
!= DMU_SPILL_BLKID
) {
1227 mutex_enter(&dn
->dn_mtx
);
1228 dnode_clear_range(dn
, db
->db_blkid
, 1, tx
);
1229 mutex_exit(&dn
->dn_mtx
);
1230 db
->db_freed_in_flight
= FALSE
;
1234 * This buffer is now part of this txg
1236 dbuf_add_ref(db
, (void *)(uintptr_t)tx
->tx_txg
);
1237 db
->db_dirtycnt
+= 1;
1238 ASSERT3U(db
->db_dirtycnt
, <=, 3);
1240 mutex_exit(&db
->db_mtx
);
1242 if (db
->db_blkid
== DMU_BONUS_BLKID
||
1243 db
->db_blkid
== DMU_SPILL_BLKID
) {
1244 mutex_enter(&dn
->dn_mtx
);
1245 ASSERT(!list_link_active(&dr
->dr_dirty_node
));
1246 list_insert_tail(&dn
->dn_dirty_records
[txgoff
], dr
);
1247 mutex_exit(&dn
->dn_mtx
);
1248 dnode_setdirty(dn
, tx
);
1251 } else if (do_free_accounting
) {
1252 blkptr_t
*bp
= db
->db_blkptr
;
1253 int64_t willfree
= (bp
&& !BP_IS_HOLE(bp
)) ?
1254 bp_get_dsize(os
->os_spa
, bp
) : db
->db
.db_size
;
1256 * This is only a guess -- if the dbuf is dirty
1257 * in a previous txg, we don't know how much
1258 * space it will use on disk yet. We should
1259 * really have the struct_rwlock to access
1260 * db_blkptr, but since this is just a guess,
1261 * it's OK if we get an odd answer.
1263 ddt_prefetch(os
->os_spa
, bp
);
1264 dnode_willuse_space(dn
, -willfree
, tx
);
1267 if (!RW_WRITE_HELD(&dn
->dn_struct_rwlock
)) {
1268 rw_enter(&dn
->dn_struct_rwlock
, RW_READER
);
1269 drop_struct_lock
= TRUE
;
1272 if (db
->db_level
== 0) {
1273 dnode_new_blkid(dn
, db
->db_blkid
, tx
, drop_struct_lock
);
1274 ASSERT(dn
->dn_maxblkid
>= db
->db_blkid
);
1277 if (db
->db_level
+1 < dn
->dn_nlevels
) {
1278 dmu_buf_impl_t
*parent
= db
->db_parent
;
1279 dbuf_dirty_record_t
*di
;
1280 int parent_held
= FALSE
;
1282 if (db
->db_parent
== NULL
|| db
->db_parent
== dn
->dn_dbuf
) {
1283 int epbs
= dn
->dn_indblkshift
- SPA_BLKPTRSHIFT
;
1285 parent
= dbuf_hold_level(dn
, db
->db_level
+1,
1286 db
->db_blkid
>> epbs
, FTAG
);
1287 ASSERT(parent
!= NULL
);
1290 if (drop_struct_lock
)
1291 rw_exit(&dn
->dn_struct_rwlock
);
1292 ASSERT3U(db
->db_level
+1, ==, parent
->db_level
);
1293 di
= dbuf_dirty(parent
, tx
);
1295 dbuf_rele(parent
, FTAG
);
1297 mutex_enter(&db
->db_mtx
);
1298 /* possible race with dbuf_undirty() */
1299 if (db
->db_last_dirty
== dr
||
1300 dn
->dn_object
== DMU_META_DNODE_OBJECT
) {
1301 mutex_enter(&di
->dt
.di
.dr_mtx
);
1302 ASSERT3U(di
->dr_txg
, ==, tx
->tx_txg
);
1303 ASSERT(!list_link_active(&dr
->dr_dirty_node
));
1304 list_insert_tail(&di
->dt
.di
.dr_children
, dr
);
1305 mutex_exit(&di
->dt
.di
.dr_mtx
);
1308 mutex_exit(&db
->db_mtx
);
1310 ASSERT(db
->db_level
+1 == dn
->dn_nlevels
);
1311 ASSERT(db
->db_blkid
< dn
->dn_nblkptr
);
1312 ASSERT(db
->db_parent
== NULL
|| db
->db_parent
== dn
->dn_dbuf
);
1313 mutex_enter(&dn
->dn_mtx
);
1314 ASSERT(!list_link_active(&dr
->dr_dirty_node
));
1315 list_insert_tail(&dn
->dn_dirty_records
[txgoff
], dr
);
1316 mutex_exit(&dn
->dn_mtx
);
1317 if (drop_struct_lock
)
1318 rw_exit(&dn
->dn_struct_rwlock
);
1321 dnode_setdirty(dn
, tx
);
1327 * Undirty a buffer in the transaction group referenced by the given
1328 * transaction. Return whether this evicted the dbuf.
1331 dbuf_undirty(dmu_buf_impl_t
*db
, dmu_tx_t
*tx
)
1334 uint64_t txg
= tx
->tx_txg
;
1335 dbuf_dirty_record_t
*dr
, **drp
;
1338 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
1339 ASSERT0(db
->db_level
);
1340 ASSERT(MUTEX_HELD(&db
->db_mtx
));
1343 * If this buffer is not dirty, we're done.
1345 for (drp
= &db
->db_last_dirty
; (dr
= *drp
) != NULL
; drp
= &dr
->dr_next
)
1346 if (dr
->dr_txg
<= txg
)
1348 if (dr
== NULL
|| dr
->dr_txg
< txg
)
1350 ASSERT(dr
->dr_txg
== txg
);
1351 ASSERT(dr
->dr_dbuf
== db
);
1357 * Note: This code will probably work even if there are concurrent
1358 * holders, but it is untested in that scenerio, as the ZPL and
1359 * ztest have additional locking (the range locks) that prevents
1360 * that type of concurrent access.
1362 ASSERT3U(refcount_count(&db
->db_holds
), ==, db
->db_dirtycnt
);
1364 dprintf_dbuf(db
, "size=%llx\n", (u_longlong_t
)db
->db
.db_size
);
1366 ASSERT(db
->db
.db_size
!= 0);
1368 /* XXX would be nice to fix up dn_towrite_space[] */
1373 * Note that there are three places in dbuf_dirty()
1374 * where this dirty record may be put on a list.
1375 * Make sure to do a list_remove corresponding to
1376 * every one of those list_insert calls.
1378 if (dr
->dr_parent
) {
1379 mutex_enter(&dr
->dr_parent
->dt
.di
.dr_mtx
);
1380 list_remove(&dr
->dr_parent
->dt
.di
.dr_children
, dr
);
1381 mutex_exit(&dr
->dr_parent
->dt
.di
.dr_mtx
);
1382 } else if (db
->db_blkid
== DMU_SPILL_BLKID
||
1383 db
->db_level
+1 == dn
->dn_nlevels
) {
1384 ASSERT(db
->db_blkptr
== NULL
|| db
->db_parent
== dn
->dn_dbuf
);
1385 mutex_enter(&dn
->dn_mtx
);
1386 list_remove(&dn
->dn_dirty_records
[txg
& TXG_MASK
], dr
);
1387 mutex_exit(&dn
->dn_mtx
);
1391 if (db
->db_state
!= DB_NOFILL
) {
1392 dbuf_unoverride(dr
);
1394 ASSERT(db
->db_buf
!= NULL
);
1395 ASSERT(dr
->dt
.dl
.dr_data
!= NULL
);
1396 if (dr
->dt
.dl
.dr_data
!= db
->db_buf
)
1397 VERIFY(arc_buf_remove_ref(dr
->dt
.dl
.dr_data
, db
));
1399 kmem_free(dr
, sizeof (dbuf_dirty_record_t
));
1401 ASSERT(db
->db_dirtycnt
> 0);
1402 db
->db_dirtycnt
-= 1;
1404 if (refcount_remove(&db
->db_holds
, (void *)(uintptr_t)txg
) == 0) {
1405 arc_buf_t
*buf
= db
->db_buf
;
1407 ASSERT(db
->db_state
== DB_NOFILL
|| arc_released(buf
));
1408 dbuf_set_data(db
, NULL
);
1409 VERIFY(arc_buf_remove_ref(buf
, db
));
1417 #pragma weak dmu_buf_will_dirty = dbuf_will_dirty
1419 dbuf_will_dirty(dmu_buf_impl_t
*db
, dmu_tx_t
*tx
)
1421 int rf
= DB_RF_MUST_SUCCEED
| DB_RF_NOPREFETCH
;
1423 ASSERT(tx
->tx_txg
!= 0);
1424 ASSERT(!refcount_is_zero(&db
->db_holds
));
1427 if (RW_WRITE_HELD(&DB_DNODE(db
)->dn_struct_rwlock
))
1428 rf
|= DB_RF_HAVESTRUCT
;
1430 (void) dbuf_read(db
, NULL
, rf
);
1431 (void) dbuf_dirty(db
, tx
);
1435 dmu_buf_will_not_fill(dmu_buf_t
*db_fake
, dmu_tx_t
*tx
)
1437 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)db_fake
;
1439 db
->db_state
= DB_NOFILL
;
1441 dmu_buf_will_fill(db_fake
, tx
);
1445 dmu_buf_will_fill(dmu_buf_t
*db_fake
, dmu_tx_t
*tx
)
1447 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)db_fake
;
1449 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
1450 ASSERT(tx
->tx_txg
!= 0);
1451 ASSERT(db
->db_level
== 0);
1452 ASSERT(!refcount_is_zero(&db
->db_holds
));
1454 ASSERT(db
->db
.db_object
!= DMU_META_DNODE_OBJECT
||
1455 dmu_tx_private_ok(tx
));
1458 (void) dbuf_dirty(db
, tx
);
1461 #pragma weak dmu_buf_fill_done = dbuf_fill_done
1464 dbuf_fill_done(dmu_buf_impl_t
*db
, dmu_tx_t
*tx
)
1466 mutex_enter(&db
->db_mtx
);
1469 if (db
->db_state
== DB_FILL
) {
1470 if (db
->db_level
== 0 && db
->db_freed_in_flight
) {
1471 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
1472 /* we were freed while filling */
1473 /* XXX dbuf_undirty? */
1474 bzero(db
->db
.db_data
, db
->db
.db_size
);
1475 db
->db_freed_in_flight
= FALSE
;
1477 db
->db_state
= DB_CACHED
;
1478 cv_broadcast(&db
->db_changed
);
1480 mutex_exit(&db
->db_mtx
);
1484 * Directly assign a provided arc buf to a given dbuf if it's not referenced
1485 * by anybody except our caller. Otherwise copy arcbuf's contents to dbuf.
1488 dbuf_assign_arcbuf(dmu_buf_impl_t
*db
, arc_buf_t
*buf
, dmu_tx_t
*tx
)
1490 ASSERT(!refcount_is_zero(&db
->db_holds
));
1491 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
1492 ASSERT(db
->db_level
== 0);
1493 ASSERT(DBUF_GET_BUFC_TYPE(db
) == ARC_BUFC_DATA
);
1494 ASSERT(buf
!= NULL
);
1495 ASSERT(arc_buf_size(buf
) == db
->db
.db_size
);
1496 ASSERT(tx
->tx_txg
!= 0);
1498 arc_return_buf(buf
, db
);
1499 ASSERT(arc_released(buf
));
1501 mutex_enter(&db
->db_mtx
);
1503 while (db
->db_state
== DB_READ
|| db
->db_state
== DB_FILL
)
1504 cv_wait(&db
->db_changed
, &db
->db_mtx
);
1506 ASSERT(db
->db_state
== DB_CACHED
|| db
->db_state
== DB_UNCACHED
);
1508 if (db
->db_state
== DB_CACHED
&&
1509 refcount_count(&db
->db_holds
) - 1 > db
->db_dirtycnt
) {
1510 mutex_exit(&db
->db_mtx
);
1511 (void) dbuf_dirty(db
, tx
);
1512 bcopy(buf
->b_data
, db
->db
.db_data
, db
->db
.db_size
);
1513 VERIFY(arc_buf_remove_ref(buf
, db
));
1514 xuio_stat_wbuf_copied();
1518 xuio_stat_wbuf_nocopy();
1519 if (db
->db_state
== DB_CACHED
) {
1520 dbuf_dirty_record_t
*dr
= db
->db_last_dirty
;
1522 ASSERT(db
->db_buf
!= NULL
);
1523 if (dr
!= NULL
&& dr
->dr_txg
== tx
->tx_txg
) {
1524 ASSERT(dr
->dt
.dl
.dr_data
== db
->db_buf
);
1525 if (!arc_released(db
->db_buf
)) {
1526 ASSERT(dr
->dt
.dl
.dr_override_state
==
1528 arc_release(db
->db_buf
, db
);
1530 dr
->dt
.dl
.dr_data
= buf
;
1531 VERIFY(arc_buf_remove_ref(db
->db_buf
, db
));
1532 } else if (dr
== NULL
|| dr
->dt
.dl
.dr_data
!= db
->db_buf
) {
1533 arc_release(db
->db_buf
, db
);
1534 VERIFY(arc_buf_remove_ref(db
->db_buf
, db
));
1538 ASSERT(db
->db_buf
== NULL
);
1539 dbuf_set_data(db
, buf
);
1540 db
->db_state
= DB_FILL
;
1541 mutex_exit(&db
->db_mtx
);
1542 (void) dbuf_dirty(db
, tx
);
1543 dbuf_fill_done(db
, tx
);
1547 * "Clear" the contents of this dbuf. This will mark the dbuf
1548 * EVICTING and clear *most* of its references. Unfortunetely,
1549 * when we are not holding the dn_dbufs_mtx, we can't clear the
1550 * entry in the dn_dbufs list. We have to wait until dbuf_destroy()
1551 * in this case. For callers from the DMU we will usually see:
1552 * dbuf_clear()->arc_buf_evict()->dbuf_do_evict()->dbuf_destroy()
1553 * For the arc callback, we will usually see:
1554 * dbuf_do_evict()->dbuf_clear();dbuf_destroy()
1555 * Sometimes, though, we will get a mix of these two:
1556 * DMU: dbuf_clear()->arc_buf_evict()
1557 * ARC: dbuf_do_evict()->dbuf_destroy()
1560 dbuf_clear(dmu_buf_impl_t
*db
)
1563 dmu_buf_impl_t
*parent
= db
->db_parent
;
1564 dmu_buf_impl_t
*dndb
;
1565 int dbuf_gone
= FALSE
;
1567 ASSERT(MUTEX_HELD(&db
->db_mtx
));
1568 ASSERT(refcount_is_zero(&db
->db_holds
));
1570 dbuf_evict_user(db
);
1572 if (db
->db_state
== DB_CACHED
) {
1573 ASSERT(db
->db
.db_data
!= NULL
);
1574 if (db
->db_blkid
== DMU_BONUS_BLKID
) {
1575 zio_buf_free(db
->db
.db_data
, DN_MAX_BONUSLEN
);
1576 arc_space_return(DN_MAX_BONUSLEN
, ARC_SPACE_OTHER
);
1578 db
->db
.db_data
= NULL
;
1579 db
->db_state
= DB_UNCACHED
;
1582 ASSERT(db
->db_state
== DB_UNCACHED
|| db
->db_state
== DB_NOFILL
);
1583 ASSERT(db
->db_data_pending
== NULL
);
1585 db
->db_state
= DB_EVICTING
;
1586 db
->db_blkptr
= NULL
;
1591 if (db
->db_blkid
!= DMU_BONUS_BLKID
&& MUTEX_HELD(&dn
->dn_dbufs_mtx
)) {
1592 list_remove(&dn
->dn_dbufs
, db
);
1593 (void) atomic_dec_32_nv(&dn
->dn_dbufs_count
);
1597 * Decrementing the dbuf count means that the hold corresponding
1598 * to the removed dbuf is no longer discounted in dnode_move(),
1599 * so the dnode cannot be moved until after we release the hold.
1600 * The membar_producer() ensures visibility of the decremented
1601 * value in dnode_move(), since DB_DNODE_EXIT doesn't actually
1605 db
->db_dnode_handle
= NULL
;
1611 dbuf_gone
= arc_buf_evict(db
->db_buf
);
1614 mutex_exit(&db
->db_mtx
);
1617 * If this dbuf is referenced from an indirect dbuf,
1618 * decrement the ref count on the indirect dbuf.
1620 if (parent
&& parent
!= dndb
)
1621 dbuf_rele(parent
, db
);
1624 __attribute__((always_inline
))
1626 dbuf_findbp(dnode_t
*dn
, int level
, uint64_t blkid
, int fail_sparse
,
1627 dmu_buf_impl_t
**parentp
, blkptr_t
**bpp
, struct dbuf_hold_impl_data
*dh
)
1634 ASSERT(blkid
!= DMU_BONUS_BLKID
);
1636 if (blkid
== DMU_SPILL_BLKID
) {
1637 mutex_enter(&dn
->dn_mtx
);
1638 if (dn
->dn_have_spill
&&
1639 (dn
->dn_phys
->dn_flags
& DNODE_FLAG_SPILL_BLKPTR
))
1640 *bpp
= &dn
->dn_phys
->dn_spill
;
1643 dbuf_add_ref(dn
->dn_dbuf
, NULL
);
1644 *parentp
= dn
->dn_dbuf
;
1645 mutex_exit(&dn
->dn_mtx
);
1649 if (dn
->dn_phys
->dn_nlevels
== 0)
1652 nlevels
= dn
->dn_phys
->dn_nlevels
;
1654 epbs
= dn
->dn_indblkshift
- SPA_BLKPTRSHIFT
;
1656 ASSERT3U(level
* epbs
, <, 64);
1657 ASSERT(RW_LOCK_HELD(&dn
->dn_struct_rwlock
));
1658 if (level
>= nlevels
||
1659 (blkid
> (dn
->dn_phys
->dn_maxblkid
>> (level
* epbs
)))) {
1660 /* the buffer has no parent yet */
1661 return (SET_ERROR(ENOENT
));
1662 } else if (level
< nlevels
-1) {
1663 /* this block is referenced from an indirect block */
1666 err
= dbuf_hold_impl(dn
, level
+1, blkid
>> epbs
,
1667 fail_sparse
, NULL
, parentp
);
1670 __dbuf_hold_impl_init(dh
+ 1, dn
, dh
->dh_level
+ 1,
1671 blkid
>> epbs
, fail_sparse
, NULL
,
1672 parentp
, dh
->dh_depth
+ 1);
1673 err
= __dbuf_hold_impl(dh
+ 1);
1677 err
= dbuf_read(*parentp
, NULL
,
1678 (DB_RF_HAVESTRUCT
| DB_RF_NOPREFETCH
| DB_RF_CANFAIL
));
1680 dbuf_rele(*parentp
, NULL
);
1684 *bpp
= ((blkptr_t
*)(*parentp
)->db
.db_data
) +
1685 (blkid
& ((1ULL << epbs
) - 1));
1688 /* the block is referenced from the dnode */
1689 ASSERT3U(level
, ==, nlevels
-1);
1690 ASSERT(dn
->dn_phys
->dn_nblkptr
== 0 ||
1691 blkid
< dn
->dn_phys
->dn_nblkptr
);
1693 dbuf_add_ref(dn
->dn_dbuf
, NULL
);
1694 *parentp
= dn
->dn_dbuf
;
1696 *bpp
= &dn
->dn_phys
->dn_blkptr
[blkid
];
1701 static dmu_buf_impl_t
*
1702 dbuf_create(dnode_t
*dn
, uint8_t level
, uint64_t blkid
,
1703 dmu_buf_impl_t
*parent
, blkptr_t
*blkptr
)
1705 objset_t
*os
= dn
->dn_objset
;
1706 dmu_buf_impl_t
*db
, *odb
;
1708 ASSERT(RW_LOCK_HELD(&dn
->dn_struct_rwlock
));
1709 ASSERT(dn
->dn_type
!= DMU_OT_NONE
);
1711 db
= kmem_cache_alloc(dbuf_cache
, KM_PUSHPAGE
);
1714 db
->db
.db_object
= dn
->dn_object
;
1715 db
->db_level
= level
;
1716 db
->db_blkid
= blkid
;
1717 db
->db_last_dirty
= NULL
;
1718 db
->db_dirtycnt
= 0;
1719 db
->db_dnode_handle
= dn
->dn_handle
;
1720 db
->db_parent
= parent
;
1721 db
->db_blkptr
= blkptr
;
1723 db
->db_user_ptr
= NULL
;
1724 db
->db_user_data_ptr_ptr
= NULL
;
1725 db
->db_evict_func
= NULL
;
1726 db
->db_immediate_evict
= 0;
1727 db
->db_freed_in_flight
= 0;
1729 if (blkid
== DMU_BONUS_BLKID
) {
1730 ASSERT3P(parent
, ==, dn
->dn_dbuf
);
1731 db
->db
.db_size
= DN_MAX_BONUSLEN
-
1732 (dn
->dn_nblkptr
-1) * sizeof (blkptr_t
);
1733 ASSERT3U(db
->db
.db_size
, >=, dn
->dn_bonuslen
);
1734 db
->db
.db_offset
= DMU_BONUS_BLKID
;
1735 db
->db_state
= DB_UNCACHED
;
1736 /* the bonus dbuf is not placed in the hash table */
1737 arc_space_consume(sizeof (dmu_buf_impl_t
), ARC_SPACE_OTHER
);
1739 } else if (blkid
== DMU_SPILL_BLKID
) {
1740 db
->db
.db_size
= (blkptr
!= NULL
) ?
1741 BP_GET_LSIZE(blkptr
) : SPA_MINBLOCKSIZE
;
1742 db
->db
.db_offset
= 0;
1745 db
->db_level
? 1<<dn
->dn_indblkshift
: dn
->dn_datablksz
;
1746 db
->db
.db_size
= blocksize
;
1747 db
->db
.db_offset
= db
->db_blkid
* blocksize
;
1751 * Hold the dn_dbufs_mtx while we get the new dbuf
1752 * in the hash table *and* added to the dbufs list.
1753 * This prevents a possible deadlock with someone
1754 * trying to look up this dbuf before its added to the
1757 mutex_enter(&dn
->dn_dbufs_mtx
);
1758 db
->db_state
= DB_EVICTING
;
1759 if ((odb
= dbuf_hash_insert(db
)) != NULL
) {
1760 /* someone else inserted it first */
1761 kmem_cache_free(dbuf_cache
, db
);
1762 mutex_exit(&dn
->dn_dbufs_mtx
);
1765 list_insert_head(&dn
->dn_dbufs
, db
);
1766 db
->db_state
= DB_UNCACHED
;
1767 mutex_exit(&dn
->dn_dbufs_mtx
);
1768 arc_space_consume(sizeof (dmu_buf_impl_t
), ARC_SPACE_OTHER
);
1770 if (parent
&& parent
!= dn
->dn_dbuf
)
1771 dbuf_add_ref(parent
, db
);
1773 ASSERT(dn
->dn_object
== DMU_META_DNODE_OBJECT
||
1774 refcount_count(&dn
->dn_holds
) > 0);
1775 (void) refcount_add(&dn
->dn_holds
, db
);
1776 (void) atomic_inc_32_nv(&dn
->dn_dbufs_count
);
1778 dprintf_dbuf(db
, "db=%p\n", db
);
1784 dbuf_do_evict(void *private)
1786 arc_buf_t
*buf
= private;
1787 dmu_buf_impl_t
*db
= buf
->b_private
;
1789 if (!MUTEX_HELD(&db
->db_mtx
))
1790 mutex_enter(&db
->db_mtx
);
1792 ASSERT(refcount_is_zero(&db
->db_holds
));
1794 if (db
->db_state
!= DB_EVICTING
) {
1795 ASSERT(db
->db_state
== DB_CACHED
);
1800 mutex_exit(&db
->db_mtx
);
1807 dbuf_destroy(dmu_buf_impl_t
*db
)
1809 ASSERT(refcount_is_zero(&db
->db_holds
));
1811 if (db
->db_blkid
!= DMU_BONUS_BLKID
) {
1813 * If this dbuf is still on the dn_dbufs list,
1814 * remove it from that list.
1816 if (db
->db_dnode_handle
!= NULL
) {
1821 mutex_enter(&dn
->dn_dbufs_mtx
);
1822 list_remove(&dn
->dn_dbufs
, db
);
1823 (void) atomic_dec_32_nv(&dn
->dn_dbufs_count
);
1824 mutex_exit(&dn
->dn_dbufs_mtx
);
1827 * Decrementing the dbuf count means that the hold
1828 * corresponding to the removed dbuf is no longer
1829 * discounted in dnode_move(), so the dnode cannot be
1830 * moved until after we release the hold.
1833 db
->db_dnode_handle
= NULL
;
1835 dbuf_hash_remove(db
);
1837 db
->db_parent
= NULL
;
1840 ASSERT(!list_link_active(&db
->db_link
));
1841 ASSERT(db
->db
.db_data
== NULL
);
1842 ASSERT(db
->db_hash_next
== NULL
);
1843 ASSERT(db
->db_blkptr
== NULL
);
1844 ASSERT(db
->db_data_pending
== NULL
);
1846 kmem_cache_free(dbuf_cache
, db
);
1847 arc_space_return(sizeof (dmu_buf_impl_t
), ARC_SPACE_OTHER
);
1851 dbuf_prefetch(dnode_t
*dn
, uint64_t blkid
)
1853 dmu_buf_impl_t
*db
= NULL
;
1854 blkptr_t
*bp
= NULL
;
1856 ASSERT(blkid
!= DMU_BONUS_BLKID
);
1857 ASSERT(RW_LOCK_HELD(&dn
->dn_struct_rwlock
));
1859 if (dnode_block_freed(dn
, blkid
))
1862 /* dbuf_find() returns with db_mtx held */
1863 if ((db
= dbuf_find(dn
, 0, blkid
))) {
1865 * This dbuf is already in the cache. We assume that
1866 * it is already CACHED, or else about to be either
1869 mutex_exit(&db
->db_mtx
);
1873 if (dbuf_findbp(dn
, 0, blkid
, TRUE
, &db
, &bp
, NULL
) == 0) {
1874 if (bp
&& !BP_IS_HOLE(bp
)) {
1875 int priority
= dn
->dn_type
== DMU_OT_DDT_ZAP
?
1876 ZIO_PRIORITY_DDT_PREFETCH
: ZIO_PRIORITY_ASYNC_READ
;
1877 dsl_dataset_t
*ds
= dn
->dn_objset
->os_dsl_dataset
;
1878 uint32_t aflags
= ARC_NOWAIT
| ARC_PREFETCH
;
1881 SET_BOOKMARK(&zb
, ds
? ds
->ds_object
: DMU_META_OBJSET
,
1882 dn
->dn_object
, 0, blkid
);
1884 (void) arc_read(NULL
, dn
->dn_objset
->os_spa
,
1885 bp
, NULL
, NULL
, priority
,
1886 ZIO_FLAG_CANFAIL
| ZIO_FLAG_SPECULATIVE
,
1890 dbuf_rele(db
, NULL
);
1894 #define DBUF_HOLD_IMPL_MAX_DEPTH 20
1897 * Returns with db_holds incremented, and db_mtx not held.
1898 * Note: dn_struct_rwlock must be held.
1901 __dbuf_hold_impl(struct dbuf_hold_impl_data
*dh
)
1903 ASSERT3S(dh
->dh_depth
, <, DBUF_HOLD_IMPL_MAX_DEPTH
);
1904 dh
->dh_parent
= NULL
;
1906 ASSERT(dh
->dh_blkid
!= DMU_BONUS_BLKID
);
1907 ASSERT(RW_LOCK_HELD(&dh
->dh_dn
->dn_struct_rwlock
));
1908 ASSERT3U(dh
->dh_dn
->dn_nlevels
, >, dh
->dh_level
);
1910 *(dh
->dh_dbp
) = NULL
;
1912 /* dbuf_find() returns with db_mtx held */
1913 dh
->dh_db
= dbuf_find(dh
->dh_dn
, dh
->dh_level
, dh
->dh_blkid
);
1915 if (dh
->dh_db
== NULL
) {
1918 ASSERT3P(dh
->dh_parent
, ==, NULL
);
1919 dh
->dh_err
= dbuf_findbp(dh
->dh_dn
, dh
->dh_level
, dh
->dh_blkid
,
1920 dh
->dh_fail_sparse
, &dh
->dh_parent
,
1922 if (dh
->dh_fail_sparse
) {
1923 if (dh
->dh_err
== 0 && dh
->dh_bp
&& BP_IS_HOLE(dh
->dh_bp
))
1924 dh
->dh_err
= SET_ERROR(ENOENT
);
1927 dbuf_rele(dh
->dh_parent
, NULL
);
1928 return (dh
->dh_err
);
1931 if (dh
->dh_err
&& dh
->dh_err
!= ENOENT
)
1932 return (dh
->dh_err
);
1933 dh
->dh_db
= dbuf_create(dh
->dh_dn
, dh
->dh_level
, dh
->dh_blkid
,
1934 dh
->dh_parent
, dh
->dh_bp
);
1937 if (dh
->dh_db
->db_buf
&& refcount_is_zero(&dh
->dh_db
->db_holds
)) {
1938 arc_buf_add_ref(dh
->dh_db
->db_buf
, dh
->dh_db
);
1939 if (dh
->dh_db
->db_buf
->b_data
== NULL
) {
1940 dbuf_clear(dh
->dh_db
);
1941 if (dh
->dh_parent
) {
1942 dbuf_rele(dh
->dh_parent
, NULL
);
1943 dh
->dh_parent
= NULL
;
1947 ASSERT3P(dh
->dh_db
->db
.db_data
, ==, dh
->dh_db
->db_buf
->b_data
);
1950 ASSERT(dh
->dh_db
->db_buf
== NULL
|| arc_referenced(dh
->dh_db
->db_buf
));
1953 * If this buffer is currently syncing out, and we are are
1954 * still referencing it from db_data, we need to make a copy
1955 * of it in case we decide we want to dirty it again in this txg.
1957 if (dh
->dh_db
->db_level
== 0 &&
1958 dh
->dh_db
->db_blkid
!= DMU_BONUS_BLKID
&&
1959 dh
->dh_dn
->dn_object
!= DMU_META_DNODE_OBJECT
&&
1960 dh
->dh_db
->db_state
== DB_CACHED
&& dh
->dh_db
->db_data_pending
) {
1961 dh
->dh_dr
= dh
->dh_db
->db_data_pending
;
1963 if (dh
->dh_dr
->dt
.dl
.dr_data
== dh
->dh_db
->db_buf
) {
1964 dh
->dh_type
= DBUF_GET_BUFC_TYPE(dh
->dh_db
);
1966 dbuf_set_data(dh
->dh_db
,
1967 arc_buf_alloc(dh
->dh_dn
->dn_objset
->os_spa
,
1968 dh
->dh_db
->db
.db_size
, dh
->dh_db
, dh
->dh_type
));
1969 bcopy(dh
->dh_dr
->dt
.dl
.dr_data
->b_data
,
1970 dh
->dh_db
->db
.db_data
, dh
->dh_db
->db
.db_size
);
1974 (void) refcount_add(&dh
->dh_db
->db_holds
, dh
->dh_tag
);
1975 dbuf_update_data(dh
->dh_db
);
1976 DBUF_VERIFY(dh
->dh_db
);
1977 mutex_exit(&dh
->dh_db
->db_mtx
);
1979 /* NOTE: we can't rele the parent until after we drop the db_mtx */
1981 dbuf_rele(dh
->dh_parent
, NULL
);
1983 ASSERT3P(DB_DNODE(dh
->dh_db
), ==, dh
->dh_dn
);
1984 ASSERT3U(dh
->dh_db
->db_blkid
, ==, dh
->dh_blkid
);
1985 ASSERT3U(dh
->dh_db
->db_level
, ==, dh
->dh_level
);
1986 *(dh
->dh_dbp
) = dh
->dh_db
;
1992 * The following code preserves the recursive function dbuf_hold_impl()
1993 * but moves the local variables AND function arguments to the heap to
1994 * minimize the stack frame size. Enough space is initially allocated
1995 * on the stack for 20 levels of recursion.
1998 dbuf_hold_impl(dnode_t
*dn
, uint8_t level
, uint64_t blkid
, int fail_sparse
,
1999 void *tag
, dmu_buf_impl_t
**dbp
)
2001 struct dbuf_hold_impl_data
*dh
;
2004 dh
= kmem_zalloc(sizeof(struct dbuf_hold_impl_data
) *
2005 DBUF_HOLD_IMPL_MAX_DEPTH
, KM_PUSHPAGE
);
2006 __dbuf_hold_impl_init(dh
, dn
, level
, blkid
, fail_sparse
, tag
, dbp
, 0);
2008 error
= __dbuf_hold_impl(dh
);
2010 kmem_free(dh
, sizeof(struct dbuf_hold_impl_data
) *
2011 DBUF_HOLD_IMPL_MAX_DEPTH
);
2017 __dbuf_hold_impl_init(struct dbuf_hold_impl_data
*dh
,
2018 dnode_t
*dn
, uint8_t level
, uint64_t blkid
, int fail_sparse
,
2019 void *tag
, dmu_buf_impl_t
**dbp
, int depth
)
2022 dh
->dh_level
= level
;
2023 dh
->dh_blkid
= blkid
;
2024 dh
->dh_fail_sparse
= fail_sparse
;
2027 dh
->dh_depth
= depth
;
2031 dbuf_hold(dnode_t
*dn
, uint64_t blkid
, void *tag
)
2034 int err
= dbuf_hold_impl(dn
, 0, blkid
, FALSE
, tag
, &db
);
2035 return (err
? NULL
: db
);
2039 dbuf_hold_level(dnode_t
*dn
, int level
, uint64_t blkid
, void *tag
)
2042 int err
= dbuf_hold_impl(dn
, level
, blkid
, FALSE
, tag
, &db
);
2043 return (err
? NULL
: db
);
2047 dbuf_create_bonus(dnode_t
*dn
)
2049 ASSERT(RW_WRITE_HELD(&dn
->dn_struct_rwlock
));
2051 ASSERT(dn
->dn_bonus
== NULL
);
2052 dn
->dn_bonus
= dbuf_create(dn
, 0, DMU_BONUS_BLKID
, dn
->dn_dbuf
, NULL
);
2056 dbuf_spill_set_blksz(dmu_buf_t
*db_fake
, uint64_t blksz
, dmu_tx_t
*tx
)
2058 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)db_fake
;
2061 if (db
->db_blkid
!= DMU_SPILL_BLKID
)
2062 return (SET_ERROR(ENOTSUP
));
2064 blksz
= SPA_MINBLOCKSIZE
;
2065 if (blksz
> SPA_MAXBLOCKSIZE
)
2066 blksz
= SPA_MAXBLOCKSIZE
;
2068 blksz
= P2ROUNDUP(blksz
, SPA_MINBLOCKSIZE
);
2072 rw_enter(&dn
->dn_struct_rwlock
, RW_WRITER
);
2073 dbuf_new_size(db
, blksz
, tx
);
2074 rw_exit(&dn
->dn_struct_rwlock
);
2081 dbuf_rm_spill(dnode_t
*dn
, dmu_tx_t
*tx
)
2083 dbuf_free_range(dn
, DMU_SPILL_BLKID
, DMU_SPILL_BLKID
, tx
);
2086 #pragma weak dmu_buf_add_ref = dbuf_add_ref
2088 dbuf_add_ref(dmu_buf_impl_t
*db
, void *tag
)
2090 VERIFY(refcount_add(&db
->db_holds
, tag
) > 1);
2094 * If you call dbuf_rele() you had better not be referencing the dnode handle
2095 * unless you have some other direct or indirect hold on the dnode. (An indirect
2096 * hold is a hold on one of the dnode's dbufs, including the bonus buffer.)
2097 * Without that, the dbuf_rele() could lead to a dnode_rele() followed by the
2098 * dnode's parent dbuf evicting its dnode handles.
2100 #pragma weak dmu_buf_rele = dbuf_rele
2102 dbuf_rele(dmu_buf_impl_t
*db
, void *tag
)
2104 mutex_enter(&db
->db_mtx
);
2105 dbuf_rele_and_unlock(db
, tag
);
2109 * dbuf_rele() for an already-locked dbuf. This is necessary to allow
2110 * db_dirtycnt and db_holds to be updated atomically.
2113 dbuf_rele_and_unlock(dmu_buf_impl_t
*db
, void *tag
)
2117 ASSERT(MUTEX_HELD(&db
->db_mtx
));
2121 * Remove the reference to the dbuf before removing its hold on the
2122 * dnode so we can guarantee in dnode_move() that a referenced bonus
2123 * buffer has a corresponding dnode hold.
2125 holds
= refcount_remove(&db
->db_holds
, tag
);
2129 * We can't freeze indirects if there is a possibility that they
2130 * may be modified in the current syncing context.
2132 if (db
->db_buf
&& holds
== (db
->db_level
== 0 ? db
->db_dirtycnt
: 0))
2133 arc_buf_freeze(db
->db_buf
);
2135 if (holds
== db
->db_dirtycnt
&&
2136 db
->db_level
== 0 && db
->db_immediate_evict
)
2137 dbuf_evict_user(db
);
2140 if (db
->db_blkid
== DMU_BONUS_BLKID
) {
2141 mutex_exit(&db
->db_mtx
);
2144 * If the dnode moves here, we cannot cross this barrier
2145 * until the move completes.
2148 (void) atomic_dec_32_nv(&DB_DNODE(db
)->dn_dbufs_count
);
2151 * The bonus buffer's dnode hold is no longer discounted
2152 * in dnode_move(). The dnode cannot move until after
2155 dnode_rele(DB_DNODE(db
), db
);
2156 } else if (db
->db_buf
== NULL
) {
2158 * This is a special case: we never associated this
2159 * dbuf with any data allocated from the ARC.
2161 ASSERT(db
->db_state
== DB_UNCACHED
||
2162 db
->db_state
== DB_NOFILL
);
2164 } else if (arc_released(db
->db_buf
)) {
2165 arc_buf_t
*buf
= db
->db_buf
;
2167 * This dbuf has anonymous data associated with it.
2169 dbuf_set_data(db
, NULL
);
2170 VERIFY(arc_buf_remove_ref(buf
, db
));
2173 VERIFY(!arc_buf_remove_ref(db
->db_buf
, db
));
2176 * A dbuf will be eligible for eviction if either the
2177 * 'primarycache' property is set or a duplicate
2178 * copy of this buffer is already cached in the arc.
2180 * In the case of the 'primarycache' a buffer
2181 * is considered for eviction if it matches the
2182 * criteria set in the property.
2184 * To decide if our buffer is considered a
2185 * duplicate, we must call into the arc to determine
2186 * if multiple buffers are referencing the same
2187 * block on-disk. If so, then we simply evict
2190 if (!DBUF_IS_CACHEABLE(db
) ||
2191 arc_buf_eviction_needed(db
->db_buf
))
2194 mutex_exit(&db
->db_mtx
);
2197 mutex_exit(&db
->db_mtx
);
2201 #pragma weak dmu_buf_refcount = dbuf_refcount
2203 dbuf_refcount(dmu_buf_impl_t
*db
)
2205 return (refcount_count(&db
->db_holds
));
2209 dmu_buf_set_user(dmu_buf_t
*db_fake
, void *user_ptr
, void *user_data_ptr_ptr
,
2210 dmu_buf_evict_func_t
*evict_func
)
2212 return (dmu_buf_update_user(db_fake
, NULL
, user_ptr
,
2213 user_data_ptr_ptr
, evict_func
));
2217 dmu_buf_set_user_ie(dmu_buf_t
*db_fake
, void *user_ptr
, void *user_data_ptr_ptr
,
2218 dmu_buf_evict_func_t
*evict_func
)
2220 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)db_fake
;
2222 db
->db_immediate_evict
= TRUE
;
2223 return (dmu_buf_update_user(db_fake
, NULL
, user_ptr
,
2224 user_data_ptr_ptr
, evict_func
));
2228 dmu_buf_update_user(dmu_buf_t
*db_fake
, void *old_user_ptr
, void *user_ptr
,
2229 void *user_data_ptr_ptr
, dmu_buf_evict_func_t
*evict_func
)
2231 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)db_fake
;
2232 ASSERT(db
->db_level
== 0);
2234 ASSERT((user_ptr
== NULL
) == (evict_func
== NULL
));
2236 mutex_enter(&db
->db_mtx
);
2238 if (db
->db_user_ptr
== old_user_ptr
) {
2239 db
->db_user_ptr
= user_ptr
;
2240 db
->db_user_data_ptr_ptr
= user_data_ptr_ptr
;
2241 db
->db_evict_func
= evict_func
;
2243 dbuf_update_data(db
);
2245 old_user_ptr
= db
->db_user_ptr
;
2248 mutex_exit(&db
->db_mtx
);
2249 return (old_user_ptr
);
2253 dmu_buf_get_user(dmu_buf_t
*db_fake
)
2255 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)db_fake
;
2256 ASSERT(!refcount_is_zero(&db
->db_holds
));
2258 return (db
->db_user_ptr
);
2262 dmu_buf_freeable(dmu_buf_t
*dbuf
)
2264 boolean_t res
= B_FALSE
;
2265 dmu_buf_impl_t
*db
= (dmu_buf_impl_t
*)dbuf
;
2268 res
= dsl_dataset_block_freeable(db
->db_objset
->os_dsl_dataset
,
2269 db
->db_blkptr
, db
->db_blkptr
->blk_birth
);
2275 dmu_buf_get_blkptr(dmu_buf_t
*db
)
2277 dmu_buf_impl_t
*dbi
= (dmu_buf_impl_t
*)db
;
2278 return (dbi
->db_blkptr
);
2282 dbuf_check_blkptr(dnode_t
*dn
, dmu_buf_impl_t
*db
)
2284 /* ASSERT(dmu_tx_is_syncing(tx) */
2285 ASSERT(MUTEX_HELD(&db
->db_mtx
));
2287 if (db
->db_blkptr
!= NULL
)
2290 if (db
->db_blkid
== DMU_SPILL_BLKID
) {
2291 db
->db_blkptr
= &dn
->dn_phys
->dn_spill
;
2292 BP_ZERO(db
->db_blkptr
);
2295 if (db
->db_level
== dn
->dn_phys
->dn_nlevels
-1) {
2297 * This buffer was allocated at a time when there was
2298 * no available blkptrs from the dnode, or it was
2299 * inappropriate to hook it in (i.e., nlevels mis-match).
2301 ASSERT(db
->db_blkid
< dn
->dn_phys
->dn_nblkptr
);
2302 ASSERT(db
->db_parent
== NULL
);
2303 db
->db_parent
= dn
->dn_dbuf
;
2304 db
->db_blkptr
= &dn
->dn_phys
->dn_blkptr
[db
->db_blkid
];
2307 dmu_buf_impl_t
*parent
= db
->db_parent
;
2308 int epbs
= dn
->dn_phys
->dn_indblkshift
- SPA_BLKPTRSHIFT
;
2310 ASSERT(dn
->dn_phys
->dn_nlevels
> 1);
2311 if (parent
== NULL
) {
2312 mutex_exit(&db
->db_mtx
);
2313 rw_enter(&dn
->dn_struct_rwlock
, RW_READER
);
2314 (void) dbuf_hold_impl(dn
, db
->db_level
+1,
2315 db
->db_blkid
>> epbs
, FALSE
, db
, &parent
);
2316 rw_exit(&dn
->dn_struct_rwlock
);
2317 mutex_enter(&db
->db_mtx
);
2318 db
->db_parent
= parent
;
2320 db
->db_blkptr
= (blkptr_t
*)parent
->db
.db_data
+
2321 (db
->db_blkid
& ((1ULL << epbs
) - 1));
2326 /* dbuf_sync_indirect() is called recursively from dbuf_sync_list() so it
2327 * is critical the we not allow the compiler to inline this function in to
2328 * dbuf_sync_list() thereby drastically bloating the stack usage.
2330 noinline
static void
2331 dbuf_sync_indirect(dbuf_dirty_record_t
*dr
, dmu_tx_t
*tx
)
2333 dmu_buf_impl_t
*db
= dr
->dr_dbuf
;
2337 ASSERT(dmu_tx_is_syncing(tx
));
2339 dprintf_dbuf_bp(db
, db
->db_blkptr
, "blkptr=%p", db
->db_blkptr
);
2341 mutex_enter(&db
->db_mtx
);
2343 ASSERT(db
->db_level
> 0);
2346 /* Read the block if it hasn't been read yet. */
2347 if (db
->db_buf
== NULL
) {
2348 mutex_exit(&db
->db_mtx
);
2349 (void) dbuf_read(db
, NULL
, DB_RF_MUST_SUCCEED
);
2350 mutex_enter(&db
->db_mtx
);
2352 ASSERT3U(db
->db_state
, ==, DB_CACHED
);
2353 ASSERT(db
->db_buf
!= NULL
);
2357 /* Indirect block size must match what the dnode thinks it is. */
2358 ASSERT3U(db
->db
.db_size
, ==, 1<<dn
->dn_phys
->dn_indblkshift
);
2359 dbuf_check_blkptr(dn
, db
);
2362 /* Provide the pending dirty record to child dbufs */
2363 db
->db_data_pending
= dr
;
2365 mutex_exit(&db
->db_mtx
);
2366 dbuf_write(dr
, db
->db_buf
, tx
);
2369 mutex_enter(&dr
->dt
.di
.dr_mtx
);
2370 dbuf_sync_list(&dr
->dt
.di
.dr_children
, tx
);
2371 ASSERT(list_head(&dr
->dt
.di
.dr_children
) == NULL
);
2372 mutex_exit(&dr
->dt
.di
.dr_mtx
);
2376 /* dbuf_sync_leaf() is called recursively from dbuf_sync_list() so it is
2377 * critical the we not allow the compiler to inline this function in to
2378 * dbuf_sync_list() thereby drastically bloating the stack usage.
2380 noinline
static void
2381 dbuf_sync_leaf(dbuf_dirty_record_t
*dr
, dmu_tx_t
*tx
)
2383 arc_buf_t
**datap
= &dr
->dt
.dl
.dr_data
;
2384 dmu_buf_impl_t
*db
= dr
->dr_dbuf
;
2387 uint64_t txg
= tx
->tx_txg
;
2389 ASSERT(dmu_tx_is_syncing(tx
));
2391 dprintf_dbuf_bp(db
, db
->db_blkptr
, "blkptr=%p", db
->db_blkptr
);
2393 mutex_enter(&db
->db_mtx
);
2395 * To be synced, we must be dirtied. But we
2396 * might have been freed after the dirty.
2398 if (db
->db_state
== DB_UNCACHED
) {
2399 /* This buffer has been freed since it was dirtied */
2400 ASSERT(db
->db
.db_data
== NULL
);
2401 } else if (db
->db_state
== DB_FILL
) {
2402 /* This buffer was freed and is now being re-filled */
2403 ASSERT(db
->db
.db_data
!= dr
->dt
.dl
.dr_data
);
2405 ASSERT(db
->db_state
== DB_CACHED
|| db
->db_state
== DB_NOFILL
);
2412 if (db
->db_blkid
== DMU_SPILL_BLKID
) {
2413 mutex_enter(&dn
->dn_mtx
);
2414 dn
->dn_phys
->dn_flags
|= DNODE_FLAG_SPILL_BLKPTR
;
2415 mutex_exit(&dn
->dn_mtx
);
2419 * If this is a bonus buffer, simply copy the bonus data into the
2420 * dnode. It will be written out when the dnode is synced (and it
2421 * will be synced, since it must have been dirty for dbuf_sync to
2424 if (db
->db_blkid
== DMU_BONUS_BLKID
) {
2425 dbuf_dirty_record_t
**drp
;
2427 ASSERT(*datap
!= NULL
);
2428 ASSERT0(db
->db_level
);
2429 ASSERT3U(dn
->dn_phys
->dn_bonuslen
, <=, DN_MAX_BONUSLEN
);
2430 bcopy(*datap
, DN_BONUS(dn
->dn_phys
), dn
->dn_phys
->dn_bonuslen
);
2433 if (*datap
!= db
->db
.db_data
) {
2434 zio_buf_free(*datap
, DN_MAX_BONUSLEN
);
2435 arc_space_return(DN_MAX_BONUSLEN
, ARC_SPACE_OTHER
);
2437 db
->db_data_pending
= NULL
;
2438 drp
= &db
->db_last_dirty
;
2440 drp
= &(*drp
)->dr_next
;
2441 ASSERT(dr
->dr_next
== NULL
);
2442 ASSERT(dr
->dr_dbuf
== db
);
2444 if (dr
->dr_dbuf
->db_level
!= 0) {
2445 mutex_destroy(&dr
->dt
.di
.dr_mtx
);
2446 list_destroy(&dr
->dt
.di
.dr_children
);
2448 kmem_free(dr
, sizeof (dbuf_dirty_record_t
));
2449 ASSERT(db
->db_dirtycnt
> 0);
2450 db
->db_dirtycnt
-= 1;
2451 dbuf_rele_and_unlock(db
, (void *)(uintptr_t)txg
);
2458 * This function may have dropped the db_mtx lock allowing a dmu_sync
2459 * operation to sneak in. As a result, we need to ensure that we
2460 * don't check the dr_override_state until we have returned from
2461 * dbuf_check_blkptr.
2463 dbuf_check_blkptr(dn
, db
);
2466 * If this buffer is in the middle of an immediate write,
2467 * wait for the synchronous IO to complete.
2469 while (dr
->dt
.dl
.dr_override_state
== DR_IN_DMU_SYNC
) {
2470 ASSERT(dn
->dn_object
!= DMU_META_DNODE_OBJECT
);
2471 cv_wait(&db
->db_changed
, &db
->db_mtx
);
2472 ASSERT(dr
->dt
.dl
.dr_override_state
!= DR_NOT_OVERRIDDEN
);
2475 if (db
->db_state
!= DB_NOFILL
&&
2476 dn
->dn_object
!= DMU_META_DNODE_OBJECT
&&
2477 refcount_count(&db
->db_holds
) > 1 &&
2478 dr
->dt
.dl
.dr_override_state
!= DR_OVERRIDDEN
&&
2479 *datap
== db
->db_buf
) {
2481 * If this buffer is currently "in use" (i.e., there
2482 * are active holds and db_data still references it),
2483 * then make a copy before we start the write so that
2484 * any modifications from the open txg will not leak
2487 * NOTE: this copy does not need to be made for
2488 * objects only modified in the syncing context (e.g.
2489 * DNONE_DNODE blocks).
2491 int blksz
= arc_buf_size(*datap
);
2492 arc_buf_contents_t type
= DBUF_GET_BUFC_TYPE(db
);
2493 *datap
= arc_buf_alloc(os
->os_spa
, blksz
, db
, type
);
2494 bcopy(db
->db
.db_data
, (*datap
)->b_data
, blksz
);
2496 db
->db_data_pending
= dr
;
2498 mutex_exit(&db
->db_mtx
);
2500 dbuf_write(dr
, *datap
, tx
);
2502 ASSERT(!list_link_active(&dr
->dr_dirty_node
));
2503 if (dn
->dn_object
== DMU_META_DNODE_OBJECT
) {
2504 list_insert_tail(&dn
->dn_dirty_records
[txg
&TXG_MASK
], dr
);
2508 * Although zio_nowait() does not "wait for an IO", it does
2509 * initiate the IO. If this is an empty write it seems plausible
2510 * that the IO could actually be completed before the nowait
2511 * returns. We need to DB_DNODE_EXIT() first in case
2512 * zio_nowait() invalidates the dbuf.
2515 zio_nowait(dr
->dr_zio
);
2520 dbuf_sync_list(list_t
*list
, dmu_tx_t
*tx
)
2522 dbuf_dirty_record_t
*dr
;
2524 while ((dr
= list_head(list
))) {
2525 if (dr
->dr_zio
!= NULL
) {
2527 * If we find an already initialized zio then we
2528 * are processing the meta-dnode, and we have finished.
2529 * The dbufs for all dnodes are put back on the list
2530 * during processing, so that we can zio_wait()
2531 * these IOs after initiating all child IOs.
2533 ASSERT3U(dr
->dr_dbuf
->db
.db_object
, ==,
2534 DMU_META_DNODE_OBJECT
);
2537 list_remove(list
, dr
);
2538 if (dr
->dr_dbuf
->db_level
> 0)
2539 dbuf_sync_indirect(dr
, tx
);
2541 dbuf_sync_leaf(dr
, tx
);
2547 dbuf_write_ready(zio_t
*zio
, arc_buf_t
*buf
, void *vdb
)
2549 dmu_buf_impl_t
*db
= vdb
;
2551 blkptr_t
*bp
= zio
->io_bp
;
2552 blkptr_t
*bp_orig
= &zio
->io_bp_orig
;
2553 spa_t
*spa
= zio
->io_spa
;
2558 ASSERT(db
->db_blkptr
== bp
);
2562 delta
= bp_get_dsize_sync(spa
, bp
) - bp_get_dsize_sync(spa
, bp_orig
);
2563 dnode_diduse_space(dn
, delta
- zio
->io_prev_space_delta
);
2564 zio
->io_prev_space_delta
= delta
;
2566 if (BP_IS_HOLE(bp
)) {
2567 ASSERT(bp
->blk_fill
== 0);
2572 ASSERT((db
->db_blkid
!= DMU_SPILL_BLKID
&&
2573 BP_GET_TYPE(bp
) == dn
->dn_type
) ||
2574 (db
->db_blkid
== DMU_SPILL_BLKID
&&
2575 BP_GET_TYPE(bp
) == dn
->dn_bonustype
));
2576 ASSERT(BP_GET_LEVEL(bp
) == db
->db_level
);
2578 mutex_enter(&db
->db_mtx
);
2581 if (db
->db_blkid
== DMU_SPILL_BLKID
) {
2582 ASSERT(dn
->dn_phys
->dn_flags
& DNODE_FLAG_SPILL_BLKPTR
);
2583 ASSERT(!(BP_IS_HOLE(db
->db_blkptr
)) &&
2584 db
->db_blkptr
== &dn
->dn_phys
->dn_spill
);
2588 if (db
->db_level
== 0) {
2589 mutex_enter(&dn
->dn_mtx
);
2590 if (db
->db_blkid
> dn
->dn_phys
->dn_maxblkid
&&
2591 db
->db_blkid
!= DMU_SPILL_BLKID
)
2592 dn
->dn_phys
->dn_maxblkid
= db
->db_blkid
;
2593 mutex_exit(&dn
->dn_mtx
);
2595 if (dn
->dn_type
== DMU_OT_DNODE
) {
2596 dnode_phys_t
*dnp
= db
->db
.db_data
;
2597 for (i
= db
->db
.db_size
>> DNODE_SHIFT
; i
> 0;
2599 if (dnp
->dn_type
!= DMU_OT_NONE
)
2606 blkptr_t
*ibp
= db
->db
.db_data
;
2607 ASSERT3U(db
->db
.db_size
, ==, 1<<dn
->dn_phys
->dn_indblkshift
);
2608 for (i
= db
->db
.db_size
>> SPA_BLKPTRSHIFT
; i
> 0; i
--, ibp
++) {
2609 if (BP_IS_HOLE(ibp
))
2611 fill
+= ibp
->blk_fill
;
2616 bp
->blk_fill
= fill
;
2618 mutex_exit(&db
->db_mtx
);
2623 dbuf_write_done(zio_t
*zio
, arc_buf_t
*buf
, void *vdb
)
2625 dmu_buf_impl_t
*db
= vdb
;
2626 blkptr_t
*bp
= zio
->io_bp
;
2627 blkptr_t
*bp_orig
= &zio
->io_bp_orig
;
2628 uint64_t txg
= zio
->io_txg
;
2629 dbuf_dirty_record_t
**drp
, *dr
;
2631 ASSERT0(zio
->io_error
);
2632 ASSERT(db
->db_blkptr
== bp
);
2635 * For nopwrites and rewrites we ensure that the bp matches our
2636 * original and bypass all the accounting.
2638 if (zio
->io_flags
& (ZIO_FLAG_IO_REWRITE
| ZIO_FLAG_NOPWRITE
)) {
2639 ASSERT(BP_EQUAL(bp
, bp_orig
));
2645 DB_GET_OBJSET(&os
, db
);
2646 ds
= os
->os_dsl_dataset
;
2649 (void) dsl_dataset_block_kill(ds
, bp_orig
, tx
, B_TRUE
);
2650 dsl_dataset_block_born(ds
, bp
, tx
);
2653 mutex_enter(&db
->db_mtx
);
2657 drp
= &db
->db_last_dirty
;
2658 while ((dr
= *drp
) != db
->db_data_pending
)
2660 ASSERT(!list_link_active(&dr
->dr_dirty_node
));
2661 ASSERT(dr
->dr_txg
== txg
);
2662 ASSERT(dr
->dr_dbuf
== db
);
2663 ASSERT(dr
->dr_next
== NULL
);
2667 if (db
->db_blkid
== DMU_SPILL_BLKID
) {
2672 ASSERT(dn
->dn_phys
->dn_flags
& DNODE_FLAG_SPILL_BLKPTR
);
2673 ASSERT(!(BP_IS_HOLE(db
->db_blkptr
)) &&
2674 db
->db_blkptr
== &dn
->dn_phys
->dn_spill
);
2679 if (db
->db_level
== 0) {
2680 ASSERT(db
->db_blkid
!= DMU_BONUS_BLKID
);
2681 ASSERT(dr
->dt
.dl
.dr_override_state
== DR_NOT_OVERRIDDEN
);
2682 if (db
->db_state
!= DB_NOFILL
) {
2683 if (dr
->dt
.dl
.dr_data
!= db
->db_buf
)
2684 VERIFY(arc_buf_remove_ref(dr
->dt
.dl
.dr_data
,
2686 else if (!arc_released(db
->db_buf
))
2687 arc_set_callback(db
->db_buf
, dbuf_do_evict
, db
);
2694 ASSERT(list_head(&dr
->dt
.di
.dr_children
) == NULL
);
2695 ASSERT3U(db
->db
.db_size
, ==, 1<<dn
->dn_phys
->dn_indblkshift
);
2696 if (!BP_IS_HOLE(db
->db_blkptr
)) {
2697 ASSERTV(int epbs
= dn
->dn_phys
->dn_indblkshift
-
2699 ASSERT3U(BP_GET_LSIZE(db
->db_blkptr
), ==,
2701 ASSERT3U(dn
->dn_phys
->dn_maxblkid
2702 >> (db
->db_level
* epbs
), >=, db
->db_blkid
);
2703 arc_set_callback(db
->db_buf
, dbuf_do_evict
, db
);
2706 mutex_destroy(&dr
->dt
.di
.dr_mtx
);
2707 list_destroy(&dr
->dt
.di
.dr_children
);
2709 kmem_free(dr
, sizeof (dbuf_dirty_record_t
));
2711 cv_broadcast(&db
->db_changed
);
2712 ASSERT(db
->db_dirtycnt
> 0);
2713 db
->db_dirtycnt
-= 1;
2714 db
->db_data_pending
= NULL
;
2715 dbuf_rele_and_unlock(db
, (void *)(uintptr_t)txg
);
2719 dbuf_write_nofill_ready(zio_t
*zio
)
2721 dbuf_write_ready(zio
, NULL
, zio
->io_private
);
2725 dbuf_write_nofill_done(zio_t
*zio
)
2727 dbuf_write_done(zio
, NULL
, zio
->io_private
);
2731 dbuf_write_override_ready(zio_t
*zio
)
2733 dbuf_dirty_record_t
*dr
= zio
->io_private
;
2734 dmu_buf_impl_t
*db
= dr
->dr_dbuf
;
2736 dbuf_write_ready(zio
, NULL
, db
);
2740 dbuf_write_override_done(zio_t
*zio
)
2742 dbuf_dirty_record_t
*dr
= zio
->io_private
;
2743 dmu_buf_impl_t
*db
= dr
->dr_dbuf
;
2744 blkptr_t
*obp
= &dr
->dt
.dl
.dr_overridden_by
;
2746 mutex_enter(&db
->db_mtx
);
2747 if (!BP_EQUAL(zio
->io_bp
, obp
)) {
2748 if (!BP_IS_HOLE(obp
))
2749 dsl_free(spa_get_dsl(zio
->io_spa
), zio
->io_txg
, obp
);
2750 arc_release(dr
->dt
.dl
.dr_data
, db
);
2752 mutex_exit(&db
->db_mtx
);
2754 dbuf_write_done(zio
, NULL
, db
);
2757 /* Issue I/O to commit a dirty buffer to disk. */
2759 dbuf_write(dbuf_dirty_record_t
*dr
, arc_buf_t
*data
, dmu_tx_t
*tx
)
2761 dmu_buf_impl_t
*db
= dr
->dr_dbuf
;
2764 dmu_buf_impl_t
*parent
= db
->db_parent
;
2765 uint64_t txg
= tx
->tx_txg
;
2775 if (db
->db_state
!= DB_NOFILL
) {
2776 if (db
->db_level
> 0 || dn
->dn_type
== DMU_OT_DNODE
) {
2778 * Private object buffers are released here rather
2779 * than in dbuf_dirty() since they are only modified
2780 * in the syncing context and we don't want the
2781 * overhead of making multiple copies of the data.
2783 if (BP_IS_HOLE(db
->db_blkptr
)) {
2786 dbuf_release_bp(db
);
2791 if (parent
!= dn
->dn_dbuf
) {
2792 /* Our parent is an indirect block. */
2793 /* We have a dirty parent that has been scheduled for write. */
2794 ASSERT(parent
&& parent
->db_data_pending
);
2795 /* Our parent's buffer is one level closer to the dnode. */
2796 ASSERT(db
->db_level
== parent
->db_level
-1);
2798 * We're about to modify our parent's db_data by modifying
2799 * our block pointer, so the parent must be released.
2801 ASSERT(arc_released(parent
->db_buf
));
2802 zio
= parent
->db_data_pending
->dr_zio
;
2804 /* Our parent is the dnode itself. */
2805 ASSERT((db
->db_level
== dn
->dn_phys
->dn_nlevels
-1 &&
2806 db
->db_blkid
!= DMU_SPILL_BLKID
) ||
2807 (db
->db_blkid
== DMU_SPILL_BLKID
&& db
->db_level
== 0));
2808 if (db
->db_blkid
!= DMU_SPILL_BLKID
)
2809 ASSERT3P(db
->db_blkptr
, ==,
2810 &dn
->dn_phys
->dn_blkptr
[db
->db_blkid
]);
2814 ASSERT(db
->db_level
== 0 || data
== db
->db_buf
);
2815 ASSERT3U(db
->db_blkptr
->blk_birth
, <=, txg
);
2818 SET_BOOKMARK(&zb
, os
->os_dsl_dataset
?
2819 os
->os_dsl_dataset
->ds_object
: DMU_META_OBJSET
,
2820 db
->db
.db_object
, db
->db_level
, db
->db_blkid
);
2822 if (db
->db_blkid
== DMU_SPILL_BLKID
)
2824 wp_flag
|= (db
->db_state
== DB_NOFILL
) ? WP_NOFILL
: 0;
2826 dmu_write_policy(os
, dn
, db
->db_level
, wp_flag
, &zp
);
2829 if (db
->db_level
== 0 && dr
->dt
.dl
.dr_override_state
== DR_OVERRIDDEN
) {
2830 ASSERT(db
->db_state
!= DB_NOFILL
);
2831 dr
->dr_zio
= zio_write(zio
, os
->os_spa
, txg
,
2832 db
->db_blkptr
, data
->b_data
, arc_buf_size(data
), &zp
,
2833 dbuf_write_override_ready
, dbuf_write_override_done
, dr
,
2834 ZIO_PRIORITY_ASYNC_WRITE
, ZIO_FLAG_MUSTSUCCEED
, &zb
);
2835 mutex_enter(&db
->db_mtx
);
2836 dr
->dt
.dl
.dr_override_state
= DR_NOT_OVERRIDDEN
;
2837 zio_write_override(dr
->dr_zio
, &dr
->dt
.dl
.dr_overridden_by
,
2838 dr
->dt
.dl
.dr_copies
, dr
->dt
.dl
.dr_nopwrite
);
2839 mutex_exit(&db
->db_mtx
);
2840 } else if (db
->db_state
== DB_NOFILL
) {
2841 ASSERT(zp
.zp_checksum
== ZIO_CHECKSUM_OFF
);
2842 dr
->dr_zio
= zio_write(zio
, os
->os_spa
, txg
,
2843 db
->db_blkptr
, NULL
, db
->db
.db_size
, &zp
,
2844 dbuf_write_nofill_ready
, dbuf_write_nofill_done
, db
,
2845 ZIO_PRIORITY_ASYNC_WRITE
,
2846 ZIO_FLAG_MUSTSUCCEED
| ZIO_FLAG_NODATA
, &zb
);
2848 ASSERT(arc_released(data
));
2849 dr
->dr_zio
= arc_write(zio
, os
->os_spa
, txg
,
2850 db
->db_blkptr
, data
, DBUF_IS_L2CACHEABLE(db
),
2851 DBUF_IS_L2COMPRESSIBLE(db
), &zp
, dbuf_write_ready
,
2852 dbuf_write_done
, db
, ZIO_PRIORITY_ASYNC_WRITE
,
2853 ZIO_FLAG_MUSTSUCCEED
, &zb
);
2857 #if defined(_KERNEL) && defined(HAVE_SPL)
2858 EXPORT_SYMBOL(dbuf_find
);
2859 EXPORT_SYMBOL(dbuf_is_metadata
);
2860 EXPORT_SYMBOL(dbuf_evict
);
2861 EXPORT_SYMBOL(dbuf_loan_arcbuf
);
2862 EXPORT_SYMBOL(dbuf_whichblock
);
2863 EXPORT_SYMBOL(dbuf_read
);
2864 EXPORT_SYMBOL(dbuf_unoverride
);
2865 EXPORT_SYMBOL(dbuf_free_range
);
2866 EXPORT_SYMBOL(dbuf_new_size
);
2867 EXPORT_SYMBOL(dbuf_release_bp
);
2868 EXPORT_SYMBOL(dbuf_dirty
);
2869 EXPORT_SYMBOL(dmu_buf_will_dirty
);
2870 EXPORT_SYMBOL(dmu_buf_will_not_fill
);
2871 EXPORT_SYMBOL(dmu_buf_will_fill
);
2872 EXPORT_SYMBOL(dmu_buf_fill_done
);
2873 EXPORT_SYMBOL(dmu_buf_rele
);
2874 EXPORT_SYMBOL(dbuf_assign_arcbuf
);
2875 EXPORT_SYMBOL(dbuf_clear
);
2876 EXPORT_SYMBOL(dbuf_prefetch
);
2877 EXPORT_SYMBOL(dbuf_hold_impl
);
2878 EXPORT_SYMBOL(dbuf_hold
);
2879 EXPORT_SYMBOL(dbuf_hold_level
);
2880 EXPORT_SYMBOL(dbuf_create_bonus
);
2881 EXPORT_SYMBOL(dbuf_spill_set_blksz
);
2882 EXPORT_SYMBOL(dbuf_rm_spill
);
2883 EXPORT_SYMBOL(dbuf_add_ref
);
2884 EXPORT_SYMBOL(dbuf_rele
);
2885 EXPORT_SYMBOL(dbuf_rele_and_unlock
);
2886 EXPORT_SYMBOL(dbuf_refcount
);
2887 EXPORT_SYMBOL(dbuf_sync_list
);
2888 EXPORT_SYMBOL(dmu_buf_set_user
);
2889 EXPORT_SYMBOL(dmu_buf_set_user_ie
);
2890 EXPORT_SYMBOL(dmu_buf_update_user
);
2891 EXPORT_SYMBOL(dmu_buf_get_user
);
2892 EXPORT_SYMBOL(dmu_buf_freeable
);