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.
25 #include <sys/zfs_context.h>
27 #include <sys/dnode.h>
29 #include <sys/dmu_impl.h>
30 #include <sys/dmu_tx.h>
31 #include <sys/dmu_objset.h>
32 #include <sys/dsl_dir.h>
33 #include <sys/dsl_dataset.h>
36 #include <sys/dmu_zfetch.h>
38 static int free_range_compar(const void *node1
, const void *node2
);
40 static kmem_cache_t
*dnode_cache
;
42 * Define DNODE_STATS to turn on statistic gathering. By default, it is only
43 * turned on when DEBUG is also defined.
50 #define DNODE_STAT_ADD(stat) ((stat)++)
52 #define DNODE_STAT_ADD(stat) /* nothing */
53 #endif /* DNODE_STATS */
55 ASSERTV(static dnode_phys_t dnode_phys_zero
);
57 int zfs_default_bs
= SPA_MINBLOCKSHIFT
;
58 int zfs_default_ibs
= DN_MAX_INDBLKSHIFT
;
61 static kmem_cbrc_t
dnode_move(void *, void *, size_t, void *);
66 dnode_cons(void *arg
, void *unused
, int kmflag
)
71 rw_init(&dn
->dn_struct_rwlock
, NULL
, RW_DEFAULT
, NULL
);
72 mutex_init(&dn
->dn_mtx
, NULL
, MUTEX_DEFAULT
, NULL
);
73 mutex_init(&dn
->dn_dbufs_mtx
, NULL
, MUTEX_DEFAULT
, NULL
);
74 cv_init(&dn
->dn_notxholds
, NULL
, CV_DEFAULT
, NULL
);
76 refcount_create(&dn
->dn_holds
);
77 refcount_create(&dn
->dn_tx_holds
);
78 list_link_init(&dn
->dn_link
);
80 bzero(&dn
->dn_next_nblkptr
[0], sizeof (dn
->dn_next_nblkptr
));
81 bzero(&dn
->dn_next_nlevels
[0], sizeof (dn
->dn_next_nlevels
));
82 bzero(&dn
->dn_next_indblkshift
[0], sizeof (dn
->dn_next_indblkshift
));
83 bzero(&dn
->dn_next_bonustype
[0], sizeof (dn
->dn_next_bonustype
));
84 bzero(&dn
->dn_rm_spillblk
[0], sizeof (dn
->dn_rm_spillblk
));
85 bzero(&dn
->dn_next_bonuslen
[0], sizeof (dn
->dn_next_bonuslen
));
86 bzero(&dn
->dn_next_blksz
[0], sizeof (dn
->dn_next_blksz
));
88 for (i
= 0; i
< TXG_SIZE
; i
++) {
89 list_link_init(&dn
->dn_dirty_link
[i
]);
90 avl_create(&dn
->dn_ranges
[i
], free_range_compar
,
91 sizeof (free_range_t
),
92 offsetof(struct free_range
, fr_node
));
93 list_create(&dn
->dn_dirty_records
[i
],
94 sizeof (dbuf_dirty_record_t
),
95 offsetof(dbuf_dirty_record_t
, dr_dirty_node
));
98 dn
->dn_allocated_txg
= 0;
100 dn
->dn_assigned_txg
= 0;
102 dn
->dn_dirtyctx_firstset
= NULL
;
104 dn
->dn_have_spill
= B_FALSE
;
114 dn
->dn_dbufs_count
= 0;
115 list_create(&dn
->dn_dbufs
, sizeof (dmu_buf_impl_t
),
116 offsetof(dmu_buf_impl_t
, db_link
));
124 dnode_dest(void *arg
, void *unused
)
129 rw_destroy(&dn
->dn_struct_rwlock
);
130 mutex_destroy(&dn
->dn_mtx
);
131 mutex_destroy(&dn
->dn_dbufs_mtx
);
132 cv_destroy(&dn
->dn_notxholds
);
133 refcount_destroy(&dn
->dn_holds
);
134 refcount_destroy(&dn
->dn_tx_holds
);
135 ASSERT(!list_link_active(&dn
->dn_link
));
137 for (i
= 0; i
< TXG_SIZE
; i
++) {
138 ASSERT(!list_link_active(&dn
->dn_dirty_link
[i
]));
139 avl_destroy(&dn
->dn_ranges
[i
]);
140 list_destroy(&dn
->dn_dirty_records
[i
]);
141 ASSERT3U(dn
->dn_next_nblkptr
[i
], ==, 0);
142 ASSERT3U(dn
->dn_next_nlevels
[i
], ==, 0);
143 ASSERT3U(dn
->dn_next_indblkshift
[i
], ==, 0);
144 ASSERT3U(dn
->dn_next_bonustype
[i
], ==, 0);
145 ASSERT3U(dn
->dn_rm_spillblk
[i
], ==, 0);
146 ASSERT3U(dn
->dn_next_bonuslen
[i
], ==, 0);
147 ASSERT3U(dn
->dn_next_blksz
[i
], ==, 0);
150 ASSERT3U(dn
->dn_allocated_txg
, ==, 0);
151 ASSERT3U(dn
->dn_free_txg
, ==, 0);
152 ASSERT3U(dn
->dn_assigned_txg
, ==, 0);
153 ASSERT3U(dn
->dn_dirtyctx
, ==, 0);
154 ASSERT3P(dn
->dn_dirtyctx_firstset
, ==, NULL
);
155 ASSERT3P(dn
->dn_bonus
, ==, NULL
);
156 ASSERT(!dn
->dn_have_spill
);
157 ASSERT3P(dn
->dn_zio
, ==, NULL
);
158 ASSERT3U(dn
->dn_oldused
, ==, 0);
159 ASSERT3U(dn
->dn_oldflags
, ==, 0);
160 ASSERT3U(dn
->dn_olduid
, ==, 0);
161 ASSERT3U(dn
->dn_oldgid
, ==, 0);
162 ASSERT3U(dn
->dn_newuid
, ==, 0);
163 ASSERT3U(dn
->dn_newgid
, ==, 0);
164 ASSERT3U(dn
->dn_id_flags
, ==, 0);
166 ASSERT3U(dn
->dn_dbufs_count
, ==, 0);
167 list_destroy(&dn
->dn_dbufs
);
173 ASSERT(dnode_cache
== NULL
);
174 dnode_cache
= kmem_cache_create("dnode_t", sizeof (dnode_t
),
175 0, dnode_cons
, dnode_dest
, NULL
, NULL
, NULL
, KMC_KMEM
);
176 kmem_cache_set_move(dnode_cache
, dnode_move
);
182 kmem_cache_destroy(dnode_cache
);
189 dnode_verify(dnode_t
*dn
)
191 int drop_struct_lock
= FALSE
;
194 ASSERT(dn
->dn_objset
);
195 ASSERT(dn
->dn_handle
->dnh_dnode
== dn
);
197 ASSERT(dn
->dn_phys
->dn_type
< DMU_OT_NUMTYPES
);
199 if (!(zfs_flags
& ZFS_DEBUG_DNODE_VERIFY
))
202 if (!RW_WRITE_HELD(&dn
->dn_struct_rwlock
)) {
203 rw_enter(&dn
->dn_struct_rwlock
, RW_READER
);
204 drop_struct_lock
= TRUE
;
206 if (dn
->dn_phys
->dn_type
!= DMU_OT_NONE
|| dn
->dn_allocated_txg
!= 0) {
208 ASSERT3U(dn
->dn_indblkshift
, <=, SPA_MAXBLOCKSHIFT
);
209 if (dn
->dn_datablkshift
) {
210 ASSERT3U(dn
->dn_datablkshift
, >=, SPA_MINBLOCKSHIFT
);
211 ASSERT3U(dn
->dn_datablkshift
, <=, SPA_MAXBLOCKSHIFT
);
212 ASSERT3U(1<<dn
->dn_datablkshift
, ==, dn
->dn_datablksz
);
214 ASSERT3U(dn
->dn_nlevels
, <=, 30);
215 ASSERT3U(dn
->dn_type
, <=, DMU_OT_NUMTYPES
);
216 ASSERT3U(dn
->dn_nblkptr
, >=, 1);
217 ASSERT3U(dn
->dn_nblkptr
, <=, DN_MAX_NBLKPTR
);
218 ASSERT3U(dn
->dn_bonuslen
, <=, DN_MAX_BONUSLEN
);
219 ASSERT3U(dn
->dn_datablksz
, ==,
220 dn
->dn_datablkszsec
<< SPA_MINBLOCKSHIFT
);
221 ASSERT3U(ISP2(dn
->dn_datablksz
), ==, dn
->dn_datablkshift
!= 0);
222 ASSERT3U((dn
->dn_nblkptr
- 1) * sizeof (blkptr_t
) +
223 dn
->dn_bonuslen
, <=, DN_MAX_BONUSLEN
);
224 for (i
= 0; i
< TXG_SIZE
; i
++) {
225 ASSERT3U(dn
->dn_next_nlevels
[i
], <=, dn
->dn_nlevels
);
228 if (dn
->dn_phys
->dn_type
!= DMU_OT_NONE
)
229 ASSERT3U(dn
->dn_phys
->dn_nlevels
, <=, dn
->dn_nlevels
);
230 ASSERT(DMU_OBJECT_IS_SPECIAL(dn
->dn_object
) || dn
->dn_dbuf
!= NULL
);
231 if (dn
->dn_dbuf
!= NULL
) {
232 ASSERT3P(dn
->dn_phys
, ==,
233 (dnode_phys_t
*)dn
->dn_dbuf
->db
.db_data
+
234 (dn
->dn_object
% (dn
->dn_dbuf
->db
.db_size
>> DNODE_SHIFT
)));
236 if (drop_struct_lock
)
237 rw_exit(&dn
->dn_struct_rwlock
);
242 dnode_byteswap(dnode_phys_t
*dnp
)
244 uint64_t *buf64
= (void*)&dnp
->dn_blkptr
;
247 if (dnp
->dn_type
== DMU_OT_NONE
) {
248 bzero(dnp
, sizeof (dnode_phys_t
));
252 dnp
->dn_datablkszsec
= BSWAP_16(dnp
->dn_datablkszsec
);
253 dnp
->dn_bonuslen
= BSWAP_16(dnp
->dn_bonuslen
);
254 dnp
->dn_maxblkid
= BSWAP_64(dnp
->dn_maxblkid
);
255 dnp
->dn_used
= BSWAP_64(dnp
->dn_used
);
258 * dn_nblkptr is only one byte, so it's OK to read it in either
259 * byte order. We can't read dn_bouslen.
261 ASSERT(dnp
->dn_indblkshift
<= SPA_MAXBLOCKSHIFT
);
262 ASSERT(dnp
->dn_nblkptr
<= DN_MAX_NBLKPTR
);
263 for (i
= 0; i
< dnp
->dn_nblkptr
* sizeof (blkptr_t
)/8; i
++)
264 buf64
[i
] = BSWAP_64(buf64
[i
]);
267 * OK to check dn_bonuslen for zero, because it won't matter if
268 * we have the wrong byte order. This is necessary because the
269 * dnode dnode is smaller than a regular dnode.
271 if (dnp
->dn_bonuslen
!= 0) {
273 * Note that the bonus length calculated here may be
274 * longer than the actual bonus buffer. This is because
275 * we always put the bonus buffer after the last block
276 * pointer (instead of packing it against the end of the
279 int off
= (dnp
->dn_nblkptr
-1) * sizeof (blkptr_t
);
280 size_t len
= DN_MAX_BONUSLEN
- off
;
281 ASSERT3U(dnp
->dn_bonustype
, <, DMU_OT_NUMTYPES
);
282 dmu_ot
[dnp
->dn_bonustype
].ot_byteswap(dnp
->dn_bonus
+ off
, len
);
285 /* Swap SPILL block if we have one */
286 if (dnp
->dn_flags
& DNODE_FLAG_SPILL_BLKPTR
)
287 byteswap_uint64_array(&dnp
->dn_spill
, sizeof (blkptr_t
));
292 dnode_buf_byteswap(void *vbuf
, size_t size
)
294 dnode_phys_t
*buf
= vbuf
;
297 ASSERT3U(sizeof (dnode_phys_t
), ==, (1<<DNODE_SHIFT
));
298 ASSERT((size
& (sizeof (dnode_phys_t
)-1)) == 0);
300 size
>>= DNODE_SHIFT
;
301 for (i
= 0; i
< size
; i
++) {
308 free_range_compar(const void *node1
, const void *node2
)
310 const free_range_t
*rp1
= node1
;
311 const free_range_t
*rp2
= node2
;
313 if (rp1
->fr_blkid
< rp2
->fr_blkid
)
315 else if (rp1
->fr_blkid
> rp2
->fr_blkid
)
321 dnode_setbonuslen(dnode_t
*dn
, int newsize
, dmu_tx_t
*tx
)
323 ASSERT3U(refcount_count(&dn
->dn_holds
), >=, 1);
325 dnode_setdirty(dn
, tx
);
326 rw_enter(&dn
->dn_struct_rwlock
, RW_WRITER
);
327 ASSERT3U(newsize
, <=, DN_MAX_BONUSLEN
-
328 (dn
->dn_nblkptr
-1) * sizeof (blkptr_t
));
329 dn
->dn_bonuslen
= newsize
;
331 dn
->dn_next_bonuslen
[tx
->tx_txg
& TXG_MASK
] = DN_ZERO_BONUSLEN
;
333 dn
->dn_next_bonuslen
[tx
->tx_txg
& TXG_MASK
] = dn
->dn_bonuslen
;
334 rw_exit(&dn
->dn_struct_rwlock
);
338 dnode_setbonus_type(dnode_t
*dn
, dmu_object_type_t newtype
, dmu_tx_t
*tx
)
340 ASSERT3U(refcount_count(&dn
->dn_holds
), >=, 1);
341 dnode_setdirty(dn
, tx
);
342 rw_enter(&dn
->dn_struct_rwlock
, RW_WRITER
);
343 dn
->dn_bonustype
= newtype
;
344 dn
->dn_next_bonustype
[tx
->tx_txg
& TXG_MASK
] = dn
->dn_bonustype
;
345 rw_exit(&dn
->dn_struct_rwlock
);
349 dnode_rm_spill(dnode_t
*dn
, dmu_tx_t
*tx
)
351 ASSERT3U(refcount_count(&dn
->dn_holds
), >=, 1);
352 ASSERT(RW_WRITE_HELD(&dn
->dn_struct_rwlock
));
353 dnode_setdirty(dn
, tx
);
354 dn
->dn_rm_spillblk
[tx
->tx_txg
&TXG_MASK
] = DN_KILL_SPILLBLK
;
355 dn
->dn_have_spill
= B_FALSE
;
359 dnode_setdblksz(dnode_t
*dn
, int size
)
361 ASSERT3U(P2PHASE(size
, SPA_MINBLOCKSIZE
), ==, 0);
362 ASSERT3U(size
, <=, SPA_MAXBLOCKSIZE
);
363 ASSERT3U(size
, >=, SPA_MINBLOCKSIZE
);
364 ASSERT3U(size
>> SPA_MINBLOCKSHIFT
, <,
365 1<<(sizeof (dn
->dn_phys
->dn_datablkszsec
) * 8));
366 dn
->dn_datablksz
= size
;
367 dn
->dn_datablkszsec
= size
>> SPA_MINBLOCKSHIFT
;
368 dn
->dn_datablkshift
= ISP2(size
) ? highbit(size
- 1) : 0;
372 dnode_create(objset_t
*os
, dnode_phys_t
*dnp
, dmu_buf_impl_t
*db
,
373 uint64_t object
, dnode_handle_t
*dnh
)
375 dnode_t
*dn
= kmem_cache_alloc(dnode_cache
, KM_PUSHPAGE
);
377 ASSERT(!POINTER_IS_VALID(dn
->dn_objset
));
381 * Defer setting dn_objset until the dnode is ready to be a candidate
382 * for the dnode_move() callback.
384 dn
->dn_object
= object
;
389 if (dnp
->dn_datablkszsec
) {
390 dnode_setdblksz(dn
, dnp
->dn_datablkszsec
<< SPA_MINBLOCKSHIFT
);
392 dn
->dn_datablksz
= 0;
393 dn
->dn_datablkszsec
= 0;
394 dn
->dn_datablkshift
= 0;
396 dn
->dn_indblkshift
= dnp
->dn_indblkshift
;
397 dn
->dn_nlevels
= dnp
->dn_nlevels
;
398 dn
->dn_type
= dnp
->dn_type
;
399 dn
->dn_nblkptr
= dnp
->dn_nblkptr
;
400 dn
->dn_checksum
= dnp
->dn_checksum
;
401 dn
->dn_compress
= dnp
->dn_compress
;
402 dn
->dn_bonustype
= dnp
->dn_bonustype
;
403 dn
->dn_bonuslen
= dnp
->dn_bonuslen
;
404 dn
->dn_maxblkid
= dnp
->dn_maxblkid
;
405 dn
->dn_have_spill
= ((dnp
->dn_flags
& DNODE_FLAG_SPILL_BLKPTR
) != 0);
408 dmu_zfetch_init(&dn
->dn_zfetch
, dn
);
410 ASSERT(dn
->dn_phys
->dn_type
< DMU_OT_NUMTYPES
);
412 mutex_enter(&os
->os_lock
);
413 list_insert_head(&os
->os_dnodes
, dn
);
416 * Everything else must be valid before assigning dn_objset makes the
417 * dnode eligible for dnode_move().
420 mutex_exit(&os
->os_lock
);
422 arc_space_consume(sizeof (dnode_t
), ARC_SPACE_OTHER
);
427 * Caller must be holding the dnode handle, which is released upon return.
430 dnode_destroy(dnode_t
*dn
)
432 objset_t
*os
= dn
->dn_objset
;
434 ASSERT((dn
->dn_id_flags
& DN_ID_NEW_EXIST
) == 0);
436 mutex_enter(&os
->os_lock
);
437 POINTER_INVALIDATE(&dn
->dn_objset
);
438 list_remove(&os
->os_dnodes
, dn
);
439 mutex_exit(&os
->os_lock
);
441 /* the dnode can no longer move, so we can release the handle */
442 zrl_remove(&dn
->dn_handle
->dnh_zrlock
);
444 dn
->dn_allocated_txg
= 0;
446 dn
->dn_assigned_txg
= 0;
449 if (dn
->dn_dirtyctx_firstset
!= NULL
) {
450 kmem_free(dn
->dn_dirtyctx_firstset
, 1);
451 dn
->dn_dirtyctx_firstset
= NULL
;
453 if (dn
->dn_bonus
!= NULL
) {
454 mutex_enter(&dn
->dn_bonus
->db_mtx
);
455 dbuf_evict(dn
->dn_bonus
);
460 dn
->dn_have_spill
= B_FALSE
;
469 dmu_zfetch_rele(&dn
->dn_zfetch
);
470 kmem_cache_free(dnode_cache
, dn
);
471 arc_space_return(sizeof (dnode_t
), ARC_SPACE_OTHER
);
475 dnode_allocate(dnode_t
*dn
, dmu_object_type_t ot
, int blocksize
, int ibs
,
476 dmu_object_type_t bonustype
, int bonuslen
, dmu_tx_t
*tx
)
481 blocksize
= 1 << zfs_default_bs
;
482 else if (blocksize
> SPA_MAXBLOCKSIZE
)
483 blocksize
= SPA_MAXBLOCKSIZE
;
485 blocksize
= P2ROUNDUP(blocksize
, SPA_MINBLOCKSIZE
);
488 ibs
= zfs_default_ibs
;
490 ibs
= MIN(MAX(ibs
, DN_MIN_INDBLKSHIFT
), DN_MAX_INDBLKSHIFT
);
492 dprintf("os=%p obj=%llu txg=%llu blocksize=%d ibs=%d\n", dn
->dn_objset
,
493 dn
->dn_object
, tx
->tx_txg
, blocksize
, ibs
);
495 ASSERT(dn
->dn_type
== DMU_OT_NONE
);
496 ASSERT(bcmp(dn
->dn_phys
, &dnode_phys_zero
, sizeof (dnode_phys_t
)) == 0);
497 ASSERT(dn
->dn_phys
->dn_type
== DMU_OT_NONE
);
498 ASSERT(ot
!= DMU_OT_NONE
);
499 ASSERT3U(ot
, <, DMU_OT_NUMTYPES
);
500 ASSERT((bonustype
== DMU_OT_NONE
&& bonuslen
== 0) ||
501 (bonustype
== DMU_OT_SA
&& bonuslen
== 0) ||
502 (bonustype
!= DMU_OT_NONE
&& bonuslen
!= 0));
503 ASSERT3U(bonustype
, <, DMU_OT_NUMTYPES
);
504 ASSERT3U(bonuslen
, <=, DN_MAX_BONUSLEN
);
505 ASSERT(dn
->dn_type
== DMU_OT_NONE
);
506 ASSERT3U(dn
->dn_maxblkid
, ==, 0);
507 ASSERT3U(dn
->dn_allocated_txg
, ==, 0);
508 ASSERT3U(dn
->dn_assigned_txg
, ==, 0);
509 ASSERT(refcount_is_zero(&dn
->dn_tx_holds
));
510 ASSERT3U(refcount_count(&dn
->dn_holds
), <=, 1);
511 ASSERT3P(list_head(&dn
->dn_dbufs
), ==, NULL
);
513 for (i
= 0; i
< TXG_SIZE
; i
++) {
514 ASSERT3U(dn
->dn_next_nblkptr
[i
], ==, 0);
515 ASSERT3U(dn
->dn_next_nlevels
[i
], ==, 0);
516 ASSERT3U(dn
->dn_next_indblkshift
[i
], ==, 0);
517 ASSERT3U(dn
->dn_next_bonuslen
[i
], ==, 0);
518 ASSERT3U(dn
->dn_next_bonustype
[i
], ==, 0);
519 ASSERT3U(dn
->dn_rm_spillblk
[i
], ==, 0);
520 ASSERT3U(dn
->dn_next_blksz
[i
], ==, 0);
521 ASSERT(!list_link_active(&dn
->dn_dirty_link
[i
]));
522 ASSERT3P(list_head(&dn
->dn_dirty_records
[i
]), ==, NULL
);
523 ASSERT3U(avl_numnodes(&dn
->dn_ranges
[i
]), ==, 0);
527 dnode_setdblksz(dn
, blocksize
);
528 dn
->dn_indblkshift
= ibs
;
530 if (bonustype
== DMU_OT_SA
) /* Maximize bonus space for SA */
534 ((DN_MAX_BONUSLEN
- bonuslen
) >> SPA_BLKPTRSHIFT
);
535 dn
->dn_bonustype
= bonustype
;
536 dn
->dn_bonuslen
= bonuslen
;
537 dn
->dn_checksum
= ZIO_CHECKSUM_INHERIT
;
538 dn
->dn_compress
= ZIO_COMPRESS_INHERIT
;
542 if (dn
->dn_dirtyctx_firstset
) {
543 kmem_free(dn
->dn_dirtyctx_firstset
, 1);
544 dn
->dn_dirtyctx_firstset
= NULL
;
547 dn
->dn_allocated_txg
= tx
->tx_txg
;
550 dnode_setdirty(dn
, tx
);
551 dn
->dn_next_indblkshift
[tx
->tx_txg
& TXG_MASK
] = ibs
;
552 dn
->dn_next_bonuslen
[tx
->tx_txg
& TXG_MASK
] = dn
->dn_bonuslen
;
553 dn
->dn_next_bonustype
[tx
->tx_txg
& TXG_MASK
] = dn
->dn_bonustype
;
554 dn
->dn_next_blksz
[tx
->tx_txg
& TXG_MASK
] = dn
->dn_datablksz
;
558 dnode_reallocate(dnode_t
*dn
, dmu_object_type_t ot
, int blocksize
,
559 dmu_object_type_t bonustype
, int bonuslen
, dmu_tx_t
*tx
)
563 ASSERT3U(blocksize
, >=, SPA_MINBLOCKSIZE
);
564 ASSERT3U(blocksize
, <=, SPA_MAXBLOCKSIZE
);
565 ASSERT3U(blocksize
% SPA_MINBLOCKSIZE
, ==, 0);
566 ASSERT(dn
->dn_object
!= DMU_META_DNODE_OBJECT
|| dmu_tx_private_ok(tx
));
567 ASSERT(tx
->tx_txg
!= 0);
568 ASSERT((bonustype
== DMU_OT_NONE
&& bonuslen
== 0) ||
569 (bonustype
!= DMU_OT_NONE
&& bonuslen
!= 0) ||
570 (bonustype
== DMU_OT_SA
&& bonuslen
== 0));
571 ASSERT3U(bonustype
, <, DMU_OT_NUMTYPES
);
572 ASSERT3U(bonuslen
, <=, DN_MAX_BONUSLEN
);
574 /* clean up any unreferenced dbufs */
575 dnode_evict_dbufs(dn
);
579 rw_enter(&dn
->dn_struct_rwlock
, RW_WRITER
);
580 dnode_setdirty(dn
, tx
);
581 if (dn
->dn_datablksz
!= blocksize
) {
582 /* change blocksize */
583 ASSERT(dn
->dn_maxblkid
== 0 &&
584 (BP_IS_HOLE(&dn
->dn_phys
->dn_blkptr
[0]) ||
585 dnode_block_freed(dn
, 0)));
586 dnode_setdblksz(dn
, blocksize
);
587 dn
->dn_next_blksz
[tx
->tx_txg
&TXG_MASK
] = blocksize
;
589 if (dn
->dn_bonuslen
!= bonuslen
)
590 dn
->dn_next_bonuslen
[tx
->tx_txg
&TXG_MASK
] = bonuslen
;
592 if (bonustype
== DMU_OT_SA
) /* Maximize bonus space for SA */
595 nblkptr
= 1 + ((DN_MAX_BONUSLEN
- bonuslen
) >> SPA_BLKPTRSHIFT
);
596 if (dn
->dn_bonustype
!= bonustype
)
597 dn
->dn_next_bonustype
[tx
->tx_txg
&TXG_MASK
] = bonustype
;
598 if (dn
->dn_nblkptr
!= nblkptr
)
599 dn
->dn_next_nblkptr
[tx
->tx_txg
&TXG_MASK
] = nblkptr
;
600 if (dn
->dn_phys
->dn_flags
& DNODE_FLAG_SPILL_BLKPTR
) {
601 dbuf_rm_spill(dn
, tx
);
602 dnode_rm_spill(dn
, tx
);
604 rw_exit(&dn
->dn_struct_rwlock
);
609 /* change bonus size and type */
610 mutex_enter(&dn
->dn_mtx
);
611 dn
->dn_bonustype
= bonustype
;
612 dn
->dn_bonuslen
= bonuslen
;
613 dn
->dn_nblkptr
= nblkptr
;
614 dn
->dn_checksum
= ZIO_CHECKSUM_INHERIT
;
615 dn
->dn_compress
= ZIO_COMPRESS_INHERIT
;
616 ASSERT3U(dn
->dn_nblkptr
, <=, DN_MAX_NBLKPTR
);
618 /* fix up the bonus db_size */
620 dn
->dn_bonus
->db
.db_size
=
621 DN_MAX_BONUSLEN
- (dn
->dn_nblkptr
-1) * sizeof (blkptr_t
);
622 ASSERT(dn
->dn_bonuslen
<= dn
->dn_bonus
->db
.db_size
);
625 dn
->dn_allocated_txg
= tx
->tx_txg
;
626 mutex_exit(&dn
->dn_mtx
);
632 uint64_t dms_dnode_invalid
;
633 uint64_t dms_dnode_recheck1
;
634 uint64_t dms_dnode_recheck2
;
635 uint64_t dms_dnode_special
;
636 uint64_t dms_dnode_handle
;
637 uint64_t dms_dnode_rwlock
;
638 uint64_t dms_dnode_active
;
640 #endif /* DNODE_STATS */
643 dnode_move_impl(dnode_t
*odn
, dnode_t
*ndn
)
647 ASSERT(!RW_LOCK_HELD(&odn
->dn_struct_rwlock
));
648 ASSERT(MUTEX_NOT_HELD(&odn
->dn_mtx
));
649 ASSERT(MUTEX_NOT_HELD(&odn
->dn_dbufs_mtx
));
650 ASSERT(!RW_LOCK_HELD(&odn
->dn_zfetch
.zf_rwlock
));
653 ndn
->dn_objset
= odn
->dn_objset
;
654 ndn
->dn_object
= odn
->dn_object
;
655 ndn
->dn_dbuf
= odn
->dn_dbuf
;
656 ndn
->dn_handle
= odn
->dn_handle
;
657 ndn
->dn_phys
= odn
->dn_phys
;
658 ndn
->dn_type
= odn
->dn_type
;
659 ndn
->dn_bonuslen
= odn
->dn_bonuslen
;
660 ndn
->dn_bonustype
= odn
->dn_bonustype
;
661 ndn
->dn_nblkptr
= odn
->dn_nblkptr
;
662 ndn
->dn_checksum
= odn
->dn_checksum
;
663 ndn
->dn_compress
= odn
->dn_compress
;
664 ndn
->dn_nlevels
= odn
->dn_nlevels
;
665 ndn
->dn_indblkshift
= odn
->dn_indblkshift
;
666 ndn
->dn_datablkshift
= odn
->dn_datablkshift
;
667 ndn
->dn_datablkszsec
= odn
->dn_datablkszsec
;
668 ndn
->dn_datablksz
= odn
->dn_datablksz
;
669 ndn
->dn_maxblkid
= odn
->dn_maxblkid
;
670 bcopy(&odn
->dn_next_nblkptr
[0], &ndn
->dn_next_nblkptr
[0],
671 sizeof (odn
->dn_next_nblkptr
));
672 bcopy(&odn
->dn_next_nlevels
[0], &ndn
->dn_next_nlevels
[0],
673 sizeof (odn
->dn_next_nlevels
));
674 bcopy(&odn
->dn_next_indblkshift
[0], &ndn
->dn_next_indblkshift
[0],
675 sizeof (odn
->dn_next_indblkshift
));
676 bcopy(&odn
->dn_next_bonustype
[0], &ndn
->dn_next_bonustype
[0],
677 sizeof (odn
->dn_next_bonustype
));
678 bcopy(&odn
->dn_rm_spillblk
[0], &ndn
->dn_rm_spillblk
[0],
679 sizeof (odn
->dn_rm_spillblk
));
680 bcopy(&odn
->dn_next_bonuslen
[0], &ndn
->dn_next_bonuslen
[0],
681 sizeof (odn
->dn_next_bonuslen
));
682 bcopy(&odn
->dn_next_blksz
[0], &ndn
->dn_next_blksz
[0],
683 sizeof (odn
->dn_next_blksz
));
684 for (i
= 0; i
< TXG_SIZE
; i
++) {
685 list_move_tail(&ndn
->dn_dirty_records
[i
],
686 &odn
->dn_dirty_records
[i
]);
688 bcopy(&odn
->dn_ranges
[0], &ndn
->dn_ranges
[0], sizeof (odn
->dn_ranges
));
689 ndn
->dn_allocated_txg
= odn
->dn_allocated_txg
;
690 ndn
->dn_free_txg
= odn
->dn_free_txg
;
691 ndn
->dn_assigned_txg
= odn
->dn_assigned_txg
;
692 ndn
->dn_dirtyctx
= odn
->dn_dirtyctx
;
693 ndn
->dn_dirtyctx_firstset
= odn
->dn_dirtyctx_firstset
;
694 ASSERT(refcount_count(&odn
->dn_tx_holds
) == 0);
695 refcount_transfer(&ndn
->dn_holds
, &odn
->dn_holds
);
696 ASSERT(list_is_empty(&ndn
->dn_dbufs
));
697 list_move_tail(&ndn
->dn_dbufs
, &odn
->dn_dbufs
);
698 ndn
->dn_dbufs_count
= odn
->dn_dbufs_count
;
699 ndn
->dn_bonus
= odn
->dn_bonus
;
700 ndn
->dn_have_spill
= odn
->dn_have_spill
;
701 ndn
->dn_zio
= odn
->dn_zio
;
702 ndn
->dn_oldused
= odn
->dn_oldused
;
703 ndn
->dn_oldflags
= odn
->dn_oldflags
;
704 ndn
->dn_olduid
= odn
->dn_olduid
;
705 ndn
->dn_oldgid
= odn
->dn_oldgid
;
706 ndn
->dn_newuid
= odn
->dn_newuid
;
707 ndn
->dn_newgid
= odn
->dn_newgid
;
708 ndn
->dn_id_flags
= odn
->dn_id_flags
;
709 dmu_zfetch_init(&ndn
->dn_zfetch
, NULL
);
710 list_move_tail(&ndn
->dn_zfetch
.zf_stream
, &odn
->dn_zfetch
.zf_stream
);
711 ndn
->dn_zfetch
.zf_dnode
= odn
->dn_zfetch
.zf_dnode
;
712 ndn
->dn_zfetch
.zf_stream_cnt
= odn
->dn_zfetch
.zf_stream_cnt
;
713 ndn
->dn_zfetch
.zf_alloc_fail
= odn
->dn_zfetch
.zf_alloc_fail
;
716 * Update back pointers. Updating the handle fixes the back pointer of
717 * every descendant dbuf as well as the bonus dbuf.
719 ASSERT(ndn
->dn_handle
->dnh_dnode
== odn
);
720 ndn
->dn_handle
->dnh_dnode
= ndn
;
721 if (ndn
->dn_zfetch
.zf_dnode
== odn
) {
722 ndn
->dn_zfetch
.zf_dnode
= ndn
;
726 * Invalidate the original dnode by clearing all of its back pointers.
729 odn
->dn_handle
= NULL
;
730 list_create(&odn
->dn_dbufs
, sizeof (dmu_buf_impl_t
),
731 offsetof(dmu_buf_impl_t
, db_link
));
732 odn
->dn_dbufs_count
= 0;
733 odn
->dn_bonus
= NULL
;
734 odn
->dn_zfetch
.zf_dnode
= NULL
;
737 * Set the low bit of the objset pointer to ensure that dnode_move()
738 * recognizes the dnode as invalid in any subsequent callback.
740 POINTER_INVALIDATE(&odn
->dn_objset
);
743 * Satisfy the destructor.
745 for (i
= 0; i
< TXG_SIZE
; i
++) {
746 list_create(&odn
->dn_dirty_records
[i
],
747 sizeof (dbuf_dirty_record_t
),
748 offsetof(dbuf_dirty_record_t
, dr_dirty_node
));
749 odn
->dn_ranges
[i
].avl_root
= NULL
;
750 odn
->dn_ranges
[i
].avl_numnodes
= 0;
751 odn
->dn_next_nlevels
[i
] = 0;
752 odn
->dn_next_indblkshift
[i
] = 0;
753 odn
->dn_next_bonustype
[i
] = 0;
754 odn
->dn_rm_spillblk
[i
] = 0;
755 odn
->dn_next_bonuslen
[i
] = 0;
756 odn
->dn_next_blksz
[i
] = 0;
758 odn
->dn_allocated_txg
= 0;
759 odn
->dn_free_txg
= 0;
760 odn
->dn_assigned_txg
= 0;
761 odn
->dn_dirtyctx
= 0;
762 odn
->dn_dirtyctx_firstset
= NULL
;
763 odn
->dn_have_spill
= B_FALSE
;
766 odn
->dn_oldflags
= 0;
771 odn
->dn_id_flags
= 0;
777 odn
->dn_moved
= (uint8_t)-1;
782 dnode_move(void *buf
, void *newbuf
, size_t size
, void *arg
)
784 dnode_t
*odn
= buf
, *ndn
= newbuf
;
790 * The dnode is on the objset's list of known dnodes if the objset
791 * pointer is valid. We set the low bit of the objset pointer when
792 * freeing the dnode to invalidate it, and the memory patterns written
793 * by kmem (baddcafe and deadbeef) set at least one of the two low bits.
794 * A newly created dnode sets the objset pointer last of all to indicate
795 * that the dnode is known and in a valid state to be moved by this
799 if (!POINTER_IS_VALID(os
)) {
800 DNODE_STAT_ADD(dnode_move_stats
.dms_dnode_invalid
);
801 return (KMEM_CBRC_DONT_KNOW
);
805 * Ensure that the objset does not go away during the move.
807 rw_enter(&os_lock
, RW_WRITER
);
808 if (os
!= odn
->dn_objset
) {
810 DNODE_STAT_ADD(dnode_move_stats
.dms_dnode_recheck1
);
811 return (KMEM_CBRC_DONT_KNOW
);
815 * If the dnode is still valid, then so is the objset. We know that no
816 * valid objset can be freed while we hold os_lock, so we can safely
817 * ensure that the objset remains in use.
819 mutex_enter(&os
->os_lock
);
822 * Recheck the objset pointer in case the dnode was removed just before
823 * acquiring the lock.
825 if (os
!= odn
->dn_objset
) {
826 mutex_exit(&os
->os_lock
);
828 DNODE_STAT_ADD(dnode_move_stats
.dms_dnode_recheck2
);
829 return (KMEM_CBRC_DONT_KNOW
);
833 * At this point we know that as long as we hold os->os_lock, the dnode
834 * cannot be freed and fields within the dnode can be safely accessed.
835 * The objset listing this dnode cannot go away as long as this dnode is
839 if (DMU_OBJECT_IS_SPECIAL(odn
->dn_object
)) {
840 mutex_exit(&os
->os_lock
);
841 DNODE_STAT_ADD(dnode_move_stats
.dms_dnode_special
);
842 return (KMEM_CBRC_NO
);
844 ASSERT(odn
->dn_dbuf
!= NULL
); /* only "special" dnodes have no parent */
847 * Lock the dnode handle to prevent the dnode from obtaining any new
848 * holds. This also prevents the descendant dbufs and the bonus dbuf
849 * from accessing the dnode, so that we can discount their holds. The
850 * handle is safe to access because we know that while the dnode cannot
851 * go away, neither can its handle. Once we hold dnh_zrlock, we can
852 * safely move any dnode referenced only by dbufs.
854 if (!zrl_tryenter(&odn
->dn_handle
->dnh_zrlock
)) {
855 mutex_exit(&os
->os_lock
);
856 DNODE_STAT_ADD(dnode_move_stats
.dms_dnode_handle
);
857 return (KMEM_CBRC_LATER
);
861 * Ensure a consistent view of the dnode's holds and the dnode's dbufs.
862 * We need to guarantee that there is a hold for every dbuf in order to
863 * determine whether the dnode is actively referenced. Falsely matching
864 * a dbuf to an active hold would lead to an unsafe move. It's possible
865 * that a thread already having an active dnode hold is about to add a
866 * dbuf, and we can't compare hold and dbuf counts while the add is in
869 if (!rw_tryenter(&odn
->dn_struct_rwlock
, RW_WRITER
)) {
870 zrl_exit(&odn
->dn_handle
->dnh_zrlock
);
871 mutex_exit(&os
->os_lock
);
872 DNODE_STAT_ADD(dnode_move_stats
.dms_dnode_rwlock
);
873 return (KMEM_CBRC_LATER
);
877 * A dbuf may be removed (evicted) without an active dnode hold. In that
878 * case, the dbuf count is decremented under the handle lock before the
879 * dbuf's hold is released. This order ensures that if we count the hold
880 * after the dbuf is removed but before its hold is released, we will
881 * treat the unmatched hold as active and exit safely. If we count the
882 * hold before the dbuf is removed, the hold is discounted, and the
883 * removal is blocked until the move completes.
885 refcount
= refcount_count(&odn
->dn_holds
);
886 ASSERT(refcount
>= 0);
887 dbufs
= odn
->dn_dbufs_count
;
889 /* We can't have more dbufs than dnode holds. */
890 ASSERT3U(dbufs
, <=, refcount
);
891 DTRACE_PROBE3(dnode__move
, dnode_t
*, odn
, int64_t, refcount
,
894 if (refcount
> dbufs
) {
895 rw_exit(&odn
->dn_struct_rwlock
);
896 zrl_exit(&odn
->dn_handle
->dnh_zrlock
);
897 mutex_exit(&os
->os_lock
);
898 DNODE_STAT_ADD(dnode_move_stats
.dms_dnode_active
);
899 return (KMEM_CBRC_LATER
);
902 rw_exit(&odn
->dn_struct_rwlock
);
905 * At this point we know that anyone with a hold on the dnode is not
906 * actively referencing it. The dnode is known and in a valid state to
907 * move. We're holding the locks needed to execute the critical section.
909 dnode_move_impl(odn
, ndn
);
911 list_link_replace(&odn
->dn_link
, &ndn
->dn_link
);
912 /* If the dnode was safe to move, the refcount cannot have changed. */
913 ASSERT(refcount
== refcount_count(&ndn
->dn_holds
));
914 ASSERT(dbufs
== ndn
->dn_dbufs_count
);
915 zrl_exit(&ndn
->dn_handle
->dnh_zrlock
); /* handle has moved */
916 mutex_exit(&os
->os_lock
);
918 return (KMEM_CBRC_YES
);
923 dnode_special_close(dnode_handle_t
*dnh
)
925 dnode_t
*dn
= dnh
->dnh_dnode
;
928 * Wait for final references to the dnode to clear. This can
929 * only happen if the arc is asyncronously evicting state that
930 * has a hold on this dnode while we are trying to evict this
933 while (refcount_count(&dn
->dn_holds
) > 0)
935 zrl_add(&dnh
->dnh_zrlock
);
936 dnode_destroy(dn
); /* implicit zrl_remove() */
937 zrl_destroy(&dnh
->dnh_zrlock
);
938 dnh
->dnh_dnode
= NULL
;
942 dnode_special_open(objset_t
*os
, dnode_phys_t
*dnp
, uint64_t object
,
945 dnode_t
*dn
= dnode_create(os
, dnp
, NULL
, object
, dnh
);
947 zrl_init(&dnh
->dnh_zrlock
);
953 dnode_buf_pageout(dmu_buf_t
*db
, void *arg
)
955 dnode_children_t
*children_dnodes
= arg
;
957 int epb
= db
->db_size
>> DNODE_SHIFT
;
959 ASSERT(epb
== children_dnodes
->dnc_count
);
961 for (i
= 0; i
< epb
; i
++) {
962 dnode_handle_t
*dnh
= &children_dnodes
->dnc_children
[i
];
966 * The dnode handle lock guards against the dnode moving to
967 * another valid address, so there is no need here to guard
968 * against changes to or from NULL.
970 if (dnh
->dnh_dnode
== NULL
) {
971 zrl_destroy(&dnh
->dnh_zrlock
);
975 zrl_add(&dnh
->dnh_zrlock
);
978 * If there are holds on this dnode, then there should
979 * be holds on the dnode's containing dbuf as well; thus
980 * it wouldn't be eligible for eviction and this function
981 * would not have been called.
983 ASSERT(refcount_is_zero(&dn
->dn_holds
));
984 ASSERT(refcount_is_zero(&dn
->dn_tx_holds
));
986 dnode_destroy(dn
); /* implicit zrl_remove() */
987 zrl_destroy(&dnh
->dnh_zrlock
);
988 dnh
->dnh_dnode
= NULL
;
990 kmem_free(children_dnodes
, sizeof (dnode_children_t
) +
991 (epb
- 1) * sizeof (dnode_handle_t
));
996 * EINVAL - invalid object number.
998 * succeeds even for free dnodes.
1001 dnode_hold_impl(objset_t
*os
, uint64_t object
, int flag
,
1002 void *tag
, dnode_t
**dnp
)
1005 int drop_struct_lock
= FALSE
;
1010 dnode_children_t
*children_dnodes
;
1011 dnode_handle_t
*dnh
;
1014 * If you are holding the spa config lock as writer, you shouldn't
1015 * be asking the DMU to do *anything* unless it's the root pool
1016 * which may require us to read from the root filesystem while
1017 * holding some (not all) of the locks as writer.
1019 ASSERT(spa_config_held(os
->os_spa
, SCL_ALL
, RW_WRITER
) == 0 ||
1020 (spa_is_root(os
->os_spa
) &&
1021 spa_config_held(os
->os_spa
, SCL_STATE
, RW_WRITER
)));
1023 if (object
== DMU_USERUSED_OBJECT
|| object
== DMU_GROUPUSED_OBJECT
) {
1024 dn
= (object
== DMU_USERUSED_OBJECT
) ?
1025 DMU_USERUSED_DNODE(os
) : DMU_GROUPUSED_DNODE(os
);
1029 if ((flag
& DNODE_MUST_BE_ALLOCATED
) && type
== DMU_OT_NONE
)
1031 if ((flag
& DNODE_MUST_BE_FREE
) && type
!= DMU_OT_NONE
)
1034 (void) refcount_add(&dn
->dn_holds
, tag
);
1039 if (object
== 0 || object
>= DN_MAX_OBJECT
)
1042 mdn
= DMU_META_DNODE(os
);
1043 ASSERT(mdn
->dn_object
== DMU_META_DNODE_OBJECT
);
1047 if (!RW_WRITE_HELD(&mdn
->dn_struct_rwlock
)) {
1048 rw_enter(&mdn
->dn_struct_rwlock
, RW_READER
);
1049 drop_struct_lock
= TRUE
;
1052 blk
= dbuf_whichblock(mdn
, object
* sizeof (dnode_phys_t
));
1054 db
= dbuf_hold(mdn
, blk
, FTAG
);
1055 if (drop_struct_lock
)
1056 rw_exit(&mdn
->dn_struct_rwlock
);
1059 err
= dbuf_read(db
, NULL
, DB_RF_CANFAIL
);
1061 dbuf_rele(db
, FTAG
);
1065 ASSERT3U(db
->db
.db_size
, >=, 1<<DNODE_SHIFT
);
1066 epb
= db
->db
.db_size
>> DNODE_SHIFT
;
1068 idx
= object
& (epb
-1);
1070 ASSERT(DB_DNODE(db
)->dn_type
== DMU_OT_DNODE
);
1071 children_dnodes
= dmu_buf_get_user(&db
->db
);
1072 if (children_dnodes
== NULL
) {
1074 dnode_children_t
*winner
;
1075 children_dnodes
= kmem_alloc(sizeof (dnode_children_t
) +
1076 (epb
- 1) * sizeof (dnode_handle_t
),
1077 KM_PUSHPAGE
| KM_NODEBUG
);
1078 children_dnodes
->dnc_count
= epb
;
1079 dnh
= &children_dnodes
->dnc_children
[0];
1080 for (i
= 0; i
< epb
; i
++) {
1081 zrl_init(&dnh
[i
].dnh_zrlock
);
1082 dnh
[i
].dnh_dnode
= NULL
;
1084 if ((winner
= dmu_buf_set_user(&db
->db
, children_dnodes
, NULL
,
1085 dnode_buf_pageout
))) {
1086 kmem_free(children_dnodes
, sizeof (dnode_children_t
) +
1087 (epb
- 1) * sizeof (dnode_handle_t
));
1088 children_dnodes
= winner
;
1091 ASSERT(children_dnodes
->dnc_count
== epb
);
1093 dnh
= &children_dnodes
->dnc_children
[idx
];
1094 zrl_add(&dnh
->dnh_zrlock
);
1095 if ((dn
= dnh
->dnh_dnode
) == NULL
) {
1096 dnode_phys_t
*phys
= (dnode_phys_t
*)db
->db
.db_data
+idx
;
1099 dn
= dnode_create(os
, phys
, db
, object
, dnh
);
1100 winner
= atomic_cas_ptr(&dnh
->dnh_dnode
, NULL
, dn
);
1101 if (winner
!= NULL
) {
1102 zrl_add(&dnh
->dnh_zrlock
);
1103 dnode_destroy(dn
); /* implicit zrl_remove() */
1108 mutex_enter(&dn
->dn_mtx
);
1110 if (dn
->dn_free_txg
||
1111 ((flag
& DNODE_MUST_BE_ALLOCATED
) && type
== DMU_OT_NONE
) ||
1112 ((flag
& DNODE_MUST_BE_FREE
) &&
1113 (type
!= DMU_OT_NONE
|| !refcount_is_zero(&dn
->dn_holds
)))) {
1114 mutex_exit(&dn
->dn_mtx
);
1115 zrl_remove(&dnh
->dnh_zrlock
);
1116 dbuf_rele(db
, FTAG
);
1117 return (type
== DMU_OT_NONE
? ENOENT
: EEXIST
);
1119 mutex_exit(&dn
->dn_mtx
);
1121 if (refcount_add(&dn
->dn_holds
, tag
) == 1)
1122 dbuf_add_ref(db
, dnh
);
1123 /* Now we can rely on the hold to prevent the dnode from moving. */
1124 zrl_remove(&dnh
->dnh_zrlock
);
1127 ASSERT3P(dn
->dn_dbuf
, ==, db
);
1128 ASSERT3U(dn
->dn_object
, ==, object
);
1129 dbuf_rele(db
, FTAG
);
1136 * Return held dnode if the object is allocated, NULL if not.
1139 dnode_hold(objset_t
*os
, uint64_t object
, void *tag
, dnode_t
**dnp
)
1141 return (dnode_hold_impl(os
, object
, DNODE_MUST_BE_ALLOCATED
, tag
, dnp
));
1145 * Can only add a reference if there is already at least one
1146 * reference on the dnode. Returns FALSE if unable to add a
1150 dnode_add_ref(dnode_t
*dn
, void *tag
)
1152 mutex_enter(&dn
->dn_mtx
);
1153 if (refcount_is_zero(&dn
->dn_holds
)) {
1154 mutex_exit(&dn
->dn_mtx
);
1157 VERIFY(1 < refcount_add(&dn
->dn_holds
, tag
));
1158 mutex_exit(&dn
->dn_mtx
);
1163 dnode_rele(dnode_t
*dn
, void *tag
)
1166 /* Get while the hold prevents the dnode from moving. */
1167 dmu_buf_impl_t
*db
= dn
->dn_dbuf
;
1168 dnode_handle_t
*dnh
= dn
->dn_handle
;
1170 mutex_enter(&dn
->dn_mtx
);
1171 refs
= refcount_remove(&dn
->dn_holds
, tag
);
1172 mutex_exit(&dn
->dn_mtx
);
1175 * It's unsafe to release the last hold on a dnode by dnode_rele() or
1176 * indirectly by dbuf_rele() while relying on the dnode handle to
1177 * prevent the dnode from moving, since releasing the last hold could
1178 * result in the dnode's parent dbuf evicting its dnode handles. For
1179 * that reason anyone calling dnode_rele() or dbuf_rele() without some
1180 * other direct or indirect hold on the dnode must first drop the dnode
1183 ASSERT(refs
> 0 || dnh
->dnh_zrlock
.zr_owner
!= curthread
);
1185 /* NOTE: the DNODE_DNODE does not have a dn_dbuf */
1186 if (refs
== 0 && db
!= NULL
) {
1188 * Another thread could add a hold to the dnode handle in
1189 * dnode_hold_impl() while holding the parent dbuf. Since the
1190 * hold on the parent dbuf prevents the handle from being
1191 * destroyed, the hold on the handle is OK. We can't yet assert
1192 * that the handle has zero references, but that will be
1193 * asserted anyway when the handle gets destroyed.
1200 dnode_setdirty(dnode_t
*dn
, dmu_tx_t
*tx
)
1202 objset_t
*os
= dn
->dn_objset
;
1203 uint64_t txg
= tx
->tx_txg
;
1205 if (DMU_OBJECT_IS_SPECIAL(dn
->dn_object
)) {
1206 dsl_dataset_dirty(os
->os_dsl_dataset
, tx
);
1213 mutex_enter(&dn
->dn_mtx
);
1214 ASSERT(dn
->dn_phys
->dn_type
|| dn
->dn_allocated_txg
);
1215 ASSERT(dn
->dn_free_txg
== 0 || dn
->dn_free_txg
>= txg
);
1216 mutex_exit(&dn
->dn_mtx
);
1220 * Determine old uid/gid when necessary
1222 dmu_objset_userquota_get_ids(dn
, B_TRUE
, tx
);
1224 mutex_enter(&os
->os_lock
);
1227 * If we are already marked dirty, we're done.
1229 if (list_link_active(&dn
->dn_dirty_link
[txg
& TXG_MASK
])) {
1230 mutex_exit(&os
->os_lock
);
1234 ASSERT(!refcount_is_zero(&dn
->dn_holds
) || list_head(&dn
->dn_dbufs
));
1235 ASSERT(dn
->dn_datablksz
!= 0);
1236 ASSERT3U(dn
->dn_next_bonuslen
[txg
&TXG_MASK
], ==, 0);
1237 ASSERT3U(dn
->dn_next_blksz
[txg
&TXG_MASK
], ==, 0);
1238 ASSERT3U(dn
->dn_next_bonustype
[txg
&TXG_MASK
], ==, 0);
1240 dprintf_ds(os
->os_dsl_dataset
, "obj=%llu txg=%llu\n",
1241 dn
->dn_object
, txg
);
1243 if (dn
->dn_free_txg
> 0 && dn
->dn_free_txg
<= txg
) {
1244 list_insert_tail(&os
->os_free_dnodes
[txg
&TXG_MASK
], dn
);
1246 list_insert_tail(&os
->os_dirty_dnodes
[txg
&TXG_MASK
], dn
);
1249 mutex_exit(&os
->os_lock
);
1252 * The dnode maintains a hold on its containing dbuf as
1253 * long as there are holds on it. Each instantiated child
1254 * dbuf maintains a hold on the dnode. When the last child
1255 * drops its hold, the dnode will drop its hold on the
1256 * containing dbuf. We add a "dirty hold" here so that the
1257 * dnode will hang around after we finish processing its
1260 VERIFY(dnode_add_ref(dn
, (void *)(uintptr_t)tx
->tx_txg
));
1262 (void) dbuf_dirty(dn
->dn_dbuf
, tx
);
1264 dsl_dataset_dirty(os
->os_dsl_dataset
, tx
);
1268 dnode_free(dnode_t
*dn
, dmu_tx_t
*tx
)
1270 int txgoff
= tx
->tx_txg
& TXG_MASK
;
1272 dprintf("dn=%p txg=%llu\n", dn
, tx
->tx_txg
);
1274 /* we should be the only holder... hopefully */
1275 /* ASSERT3U(refcount_count(&dn->dn_holds), ==, 1); */
1277 mutex_enter(&dn
->dn_mtx
);
1278 if (dn
->dn_type
== DMU_OT_NONE
|| dn
->dn_free_txg
) {
1279 mutex_exit(&dn
->dn_mtx
);
1282 dn
->dn_free_txg
= tx
->tx_txg
;
1283 mutex_exit(&dn
->dn_mtx
);
1286 * If the dnode is already dirty, it needs to be moved from
1287 * the dirty list to the free list.
1289 mutex_enter(&dn
->dn_objset
->os_lock
);
1290 if (list_link_active(&dn
->dn_dirty_link
[txgoff
])) {
1291 list_remove(&dn
->dn_objset
->os_dirty_dnodes
[txgoff
], dn
);
1292 list_insert_tail(&dn
->dn_objset
->os_free_dnodes
[txgoff
], dn
);
1293 mutex_exit(&dn
->dn_objset
->os_lock
);
1295 mutex_exit(&dn
->dn_objset
->os_lock
);
1296 dnode_setdirty(dn
, tx
);
1301 * Try to change the block size for the indicated dnode. This can only
1302 * succeed if there are no blocks allocated or dirty beyond first block
1305 dnode_set_blksz(dnode_t
*dn
, uint64_t size
, int ibs
, dmu_tx_t
*tx
)
1307 dmu_buf_impl_t
*db
, *db_next
;
1311 size
= SPA_MINBLOCKSIZE
;
1312 if (size
> SPA_MAXBLOCKSIZE
)
1313 size
= SPA_MAXBLOCKSIZE
;
1315 size
= P2ROUNDUP(size
, SPA_MINBLOCKSIZE
);
1317 if (ibs
== dn
->dn_indblkshift
)
1320 if (size
>> SPA_MINBLOCKSHIFT
== dn
->dn_datablkszsec
&& ibs
== 0)
1323 rw_enter(&dn
->dn_struct_rwlock
, RW_WRITER
);
1325 /* Check for any allocated blocks beyond the first */
1326 if (dn
->dn_phys
->dn_maxblkid
!= 0)
1329 mutex_enter(&dn
->dn_dbufs_mtx
);
1330 for (db
= list_head(&dn
->dn_dbufs
); db
; db
= db_next
) {
1331 db_next
= list_next(&dn
->dn_dbufs
, db
);
1333 if (db
->db_blkid
!= 0 && db
->db_blkid
!= DMU_BONUS_BLKID
&&
1334 db
->db_blkid
!= DMU_SPILL_BLKID
) {
1335 mutex_exit(&dn
->dn_dbufs_mtx
);
1339 mutex_exit(&dn
->dn_dbufs_mtx
);
1341 if (ibs
&& dn
->dn_nlevels
!= 1)
1344 /* resize the old block */
1345 err
= dbuf_hold_impl(dn
, 0, 0, TRUE
, FTAG
, &db
);
1347 dbuf_new_size(db
, size
, tx
);
1348 else if (err
!= ENOENT
)
1351 dnode_setdblksz(dn
, size
);
1352 dnode_setdirty(dn
, tx
);
1353 dn
->dn_next_blksz
[tx
->tx_txg
&TXG_MASK
] = size
;
1355 dn
->dn_indblkshift
= ibs
;
1356 dn
->dn_next_indblkshift
[tx
->tx_txg
&TXG_MASK
] = ibs
;
1358 /* rele after we have fixed the blocksize in the dnode */
1360 dbuf_rele(db
, FTAG
);
1362 rw_exit(&dn
->dn_struct_rwlock
);
1366 rw_exit(&dn
->dn_struct_rwlock
);
1370 /* read-holding callers must not rely on the lock being continuously held */
1372 dnode_new_blkid(dnode_t
*dn
, uint64_t blkid
, dmu_tx_t
*tx
, boolean_t have_read
)
1374 uint64_t txgoff
= tx
->tx_txg
& TXG_MASK
;
1375 int epbs
, new_nlevels
;
1378 ASSERT(blkid
!= DMU_BONUS_BLKID
);
1381 RW_READ_HELD(&dn
->dn_struct_rwlock
) :
1382 RW_WRITE_HELD(&dn
->dn_struct_rwlock
));
1385 * if we have a read-lock, check to see if we need to do any work
1386 * before upgrading to a write-lock.
1389 if (blkid
<= dn
->dn_maxblkid
)
1392 if (!rw_tryupgrade(&dn
->dn_struct_rwlock
)) {
1393 rw_exit(&dn
->dn_struct_rwlock
);
1394 rw_enter(&dn
->dn_struct_rwlock
, RW_WRITER
);
1398 if (blkid
<= dn
->dn_maxblkid
)
1401 dn
->dn_maxblkid
= blkid
;
1404 * Compute the number of levels necessary to support the new maxblkid.
1407 epbs
= dn
->dn_indblkshift
- SPA_BLKPTRSHIFT
;
1408 for (sz
= dn
->dn_nblkptr
;
1409 sz
<= blkid
&& sz
>= dn
->dn_nblkptr
; sz
<<= epbs
)
1412 if (new_nlevels
> dn
->dn_nlevels
) {
1413 int old_nlevels
= dn
->dn_nlevels
;
1416 dbuf_dirty_record_t
*new, *dr
, *dr_next
;
1418 dn
->dn_nlevels
= new_nlevels
;
1420 ASSERT3U(new_nlevels
, >, dn
->dn_next_nlevels
[txgoff
]);
1421 dn
->dn_next_nlevels
[txgoff
] = new_nlevels
;
1423 /* dirty the left indirects */
1424 db
= dbuf_hold_level(dn
, old_nlevels
, 0, FTAG
);
1426 new = dbuf_dirty(db
, tx
);
1427 dbuf_rele(db
, FTAG
);
1429 /* transfer the dirty records to the new indirect */
1430 mutex_enter(&dn
->dn_mtx
);
1431 mutex_enter(&new->dt
.di
.dr_mtx
);
1432 list
= &dn
->dn_dirty_records
[txgoff
];
1433 for (dr
= list_head(list
); dr
; dr
= dr_next
) {
1434 dr_next
= list_next(&dn
->dn_dirty_records
[txgoff
], dr
);
1435 if (dr
->dr_dbuf
->db_level
!= new_nlevels
-1 &&
1436 dr
->dr_dbuf
->db_blkid
!= DMU_BONUS_BLKID
&&
1437 dr
->dr_dbuf
->db_blkid
!= DMU_SPILL_BLKID
) {
1438 ASSERT(dr
->dr_dbuf
->db_level
== old_nlevels
-1);
1439 list_remove(&dn
->dn_dirty_records
[txgoff
], dr
);
1440 list_insert_tail(&new->dt
.di
.dr_children
, dr
);
1441 dr
->dr_parent
= new;
1444 mutex_exit(&new->dt
.di
.dr_mtx
);
1445 mutex_exit(&dn
->dn_mtx
);
1450 rw_downgrade(&dn
->dn_struct_rwlock
);
1454 dnode_clear_range(dnode_t
*dn
, uint64_t blkid
, uint64_t nblks
, dmu_tx_t
*tx
)
1456 avl_tree_t
*tree
= &dn
->dn_ranges
[tx
->tx_txg
&TXG_MASK
];
1459 free_range_t rp_tofind
;
1460 uint64_t endblk
= blkid
+ nblks
;
1462 ASSERT(MUTEX_HELD(&dn
->dn_mtx
));
1463 ASSERT(nblks
<= UINT64_MAX
- blkid
); /* no overflow */
1465 dprintf_dnode(dn
, "blkid=%llu nblks=%llu txg=%llu\n",
1466 blkid
, nblks
, tx
->tx_txg
);
1467 rp_tofind
.fr_blkid
= blkid
;
1468 rp
= avl_find(tree
, &rp_tofind
, &where
);
1470 rp
= avl_nearest(tree
, where
, AVL_BEFORE
);
1472 rp
= avl_nearest(tree
, where
, AVL_AFTER
);
1474 while (rp
&& (rp
->fr_blkid
<= blkid
+ nblks
)) {
1475 uint64_t fr_endblk
= rp
->fr_blkid
+ rp
->fr_nblks
;
1476 free_range_t
*nrp
= AVL_NEXT(tree
, rp
);
1478 if (blkid
<= rp
->fr_blkid
&& endblk
>= fr_endblk
) {
1479 /* clear this entire range */
1480 avl_remove(tree
, rp
);
1481 kmem_free(rp
, sizeof (free_range_t
));
1482 } else if (blkid
<= rp
->fr_blkid
&&
1483 endblk
> rp
->fr_blkid
&& endblk
< fr_endblk
) {
1484 /* clear the beginning of this range */
1485 rp
->fr_blkid
= endblk
;
1486 rp
->fr_nblks
= fr_endblk
- endblk
;
1487 } else if (blkid
> rp
->fr_blkid
&& blkid
< fr_endblk
&&
1488 endblk
>= fr_endblk
) {
1489 /* clear the end of this range */
1490 rp
->fr_nblks
= blkid
- rp
->fr_blkid
;
1491 } else if (blkid
> rp
->fr_blkid
&& endblk
< fr_endblk
) {
1492 /* clear a chunk out of this range */
1493 free_range_t
*new_rp
=
1494 kmem_alloc(sizeof (free_range_t
), KM_PUSHPAGE
);
1496 new_rp
->fr_blkid
= endblk
;
1497 new_rp
->fr_nblks
= fr_endblk
- endblk
;
1498 avl_insert_here(tree
, new_rp
, rp
, AVL_AFTER
);
1499 rp
->fr_nblks
= blkid
- rp
->fr_blkid
;
1501 /* there may be no overlap */
1507 dnode_free_range(dnode_t
*dn
, uint64_t off
, uint64_t len
, dmu_tx_t
*tx
)
1510 uint64_t blkoff
, blkid
, nblks
;
1511 int blksz
, blkshift
, head
, tail
;
1515 rw_enter(&dn
->dn_struct_rwlock
, RW_WRITER
);
1516 blksz
= dn
->dn_datablksz
;
1517 blkshift
= dn
->dn_datablkshift
;
1518 epbs
= dn
->dn_indblkshift
- SPA_BLKPTRSHIFT
;
1521 len
= UINT64_MAX
- off
;
1526 * First, block align the region to free:
1529 head
= P2NPHASE(off
, blksz
);
1530 blkoff
= P2PHASE(off
, blksz
);
1531 if ((off
>> blkshift
) > dn
->dn_maxblkid
)
1534 ASSERT(dn
->dn_maxblkid
== 0);
1535 if (off
== 0 && len
>= blksz
) {
1536 /* Freeing the whole block; fast-track this request */
1540 } else if (off
>= blksz
) {
1541 /* Freeing past end-of-data */
1544 /* Freeing part of the block. */
1546 ASSERT3U(head
, >, 0);
1550 /* zero out any partial block data at the start of the range */
1552 ASSERT3U(blkoff
+ head
, ==, blksz
);
1555 if (dbuf_hold_impl(dn
, 0, dbuf_whichblock(dn
, off
), TRUE
,
1559 /* don't dirty if it isn't on disk and isn't dirty */
1560 if (db
->db_last_dirty
||
1561 (db
->db_blkptr
&& !BP_IS_HOLE(db
->db_blkptr
))) {
1562 rw_exit(&dn
->dn_struct_rwlock
);
1563 dbuf_will_dirty(db
, tx
);
1564 rw_enter(&dn
->dn_struct_rwlock
, RW_WRITER
);
1565 data
= db
->db
.db_data
;
1566 bzero(data
+ blkoff
, head
);
1568 dbuf_rele(db
, FTAG
);
1574 /* If the range was less than one block, we're done */
1578 /* If the remaining range is past end of file, we're done */
1579 if ((off
>> blkshift
) > dn
->dn_maxblkid
)
1582 ASSERT(ISP2(blksz
));
1586 tail
= P2PHASE(len
, blksz
);
1588 ASSERT3U(P2PHASE(off
, blksz
), ==, 0);
1589 /* zero out any partial block data at the end of the range */
1593 if (dbuf_hold_impl(dn
, 0, dbuf_whichblock(dn
, off
+len
),
1594 TRUE
, FTAG
, &db
) == 0) {
1595 /* don't dirty if not on disk and not dirty */
1596 if (db
->db_last_dirty
||
1597 (db
->db_blkptr
&& !BP_IS_HOLE(db
->db_blkptr
))) {
1598 rw_exit(&dn
->dn_struct_rwlock
);
1599 dbuf_will_dirty(db
, tx
);
1600 rw_enter(&dn
->dn_struct_rwlock
, RW_WRITER
);
1601 bzero(db
->db
.db_data
, tail
);
1603 dbuf_rele(db
, FTAG
);
1608 /* If the range did not include a full block, we are done */
1612 ASSERT(IS_P2ALIGNED(off
, blksz
));
1613 ASSERT(trunc
|| IS_P2ALIGNED(len
, blksz
));
1614 blkid
= off
>> blkshift
;
1615 nblks
= len
>> blkshift
;
1620 * Read in and mark all the level-1 indirects dirty,
1621 * so that they will stay in memory until syncing phase.
1622 * Always dirty the first and last indirect to make sure
1623 * we dirty all the partial indirects.
1625 if (dn
->dn_nlevels
> 1) {
1626 uint64_t i
, first
, last
;
1627 int shift
= epbs
+ dn
->dn_datablkshift
;
1629 first
= blkid
>> epbs
;
1630 if ((db
= dbuf_hold_level(dn
, 1, first
, FTAG
))) {
1631 dbuf_will_dirty(db
, tx
);
1632 dbuf_rele(db
, FTAG
);
1635 last
= dn
->dn_maxblkid
>> epbs
;
1637 last
= (blkid
+ nblks
- 1) >> epbs
;
1638 if (last
> first
&& (db
= dbuf_hold_level(dn
, 1, last
, FTAG
))) {
1639 dbuf_will_dirty(db
, tx
);
1640 dbuf_rele(db
, FTAG
);
1642 for (i
= first
+ 1; i
< last
; i
++) {
1643 uint64_t ibyte
= i
<< shift
;
1646 err
= dnode_next_offset(dn
,
1647 DNODE_FIND_HAVELOCK
, &ibyte
, 1, 1, 0);
1649 if (err
== ESRCH
|| i
>= last
)
1652 db
= dbuf_hold_level(dn
, 1, i
, FTAG
);
1654 dbuf_will_dirty(db
, tx
);
1655 dbuf_rele(db
, FTAG
);
1661 * Add this range to the dnode range list.
1662 * We will finish up this free operation in the syncing phase.
1664 mutex_enter(&dn
->dn_mtx
);
1665 dnode_clear_range(dn
, blkid
, nblks
, tx
);
1667 free_range_t
*rp
, *found
;
1669 avl_tree_t
*tree
= &dn
->dn_ranges
[tx
->tx_txg
&TXG_MASK
];
1671 /* Add new range to dn_ranges */
1672 rp
= kmem_alloc(sizeof (free_range_t
), KM_PUSHPAGE
);
1673 rp
->fr_blkid
= blkid
;
1674 rp
->fr_nblks
= nblks
;
1675 found
= avl_find(tree
, rp
, &where
);
1676 ASSERT(found
== NULL
);
1677 avl_insert(tree
, rp
, where
);
1678 dprintf_dnode(dn
, "blkid=%llu nblks=%llu txg=%llu\n",
1679 blkid
, nblks
, tx
->tx_txg
);
1681 mutex_exit(&dn
->dn_mtx
);
1683 dbuf_free_range(dn
, blkid
, blkid
+ nblks
- 1, tx
);
1684 dnode_setdirty(dn
, tx
);
1686 if (trunc
&& dn
->dn_maxblkid
>= (off
>> blkshift
))
1687 dn
->dn_maxblkid
= (off
>> blkshift
? (off
>> blkshift
) - 1 : 0);
1689 rw_exit(&dn
->dn_struct_rwlock
);
1693 dnode_spill_freed(dnode_t
*dn
)
1697 mutex_enter(&dn
->dn_mtx
);
1698 for (i
= 0; i
< TXG_SIZE
; i
++) {
1699 if (dn
->dn_rm_spillblk
[i
] == DN_KILL_SPILLBLK
)
1702 mutex_exit(&dn
->dn_mtx
);
1703 return (i
< TXG_SIZE
);
1706 /* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */
1708 dnode_block_freed(dnode_t
*dn
, uint64_t blkid
)
1710 free_range_t range_tofind
;
1711 void *dp
= spa_get_dsl(dn
->dn_objset
->os_spa
);
1714 if (blkid
== DMU_BONUS_BLKID
)
1718 * If we're in the process of opening the pool, dp will not be
1719 * set yet, but there shouldn't be anything dirty.
1724 if (dn
->dn_free_txg
)
1727 if (blkid
== DMU_SPILL_BLKID
)
1728 return (dnode_spill_freed(dn
));
1730 range_tofind
.fr_blkid
= blkid
;
1731 mutex_enter(&dn
->dn_mtx
);
1732 for (i
= 0; i
< TXG_SIZE
; i
++) {
1733 free_range_t
*range_found
;
1736 range_found
= avl_find(&dn
->dn_ranges
[i
], &range_tofind
, &idx
);
1738 ASSERT(range_found
->fr_nblks
> 0);
1741 range_found
= avl_nearest(&dn
->dn_ranges
[i
], idx
, AVL_BEFORE
);
1743 range_found
->fr_blkid
+ range_found
->fr_nblks
> blkid
)
1746 mutex_exit(&dn
->dn_mtx
);
1747 return (i
< TXG_SIZE
);
1750 /* call from syncing context when we actually write/free space for this dnode */
1752 dnode_diduse_space(dnode_t
*dn
, int64_t delta
)
1755 dprintf_dnode(dn
, "dn=%p dnp=%p used=%llu delta=%lld\n",
1757 (u_longlong_t
)dn
->dn_phys
->dn_used
,
1760 mutex_enter(&dn
->dn_mtx
);
1761 space
= DN_USED_BYTES(dn
->dn_phys
);
1763 ASSERT3U(space
+ delta
, >=, space
); /* no overflow */
1765 ASSERT3U(space
, >=, -delta
); /* no underflow */
1768 if (spa_version(dn
->dn_objset
->os_spa
) < SPA_VERSION_DNODE_BYTES
) {
1769 ASSERT((dn
->dn_phys
->dn_flags
& DNODE_FLAG_USED_BYTES
) == 0);
1770 ASSERT3U(P2PHASE(space
, 1<<DEV_BSHIFT
), ==, 0);
1771 dn
->dn_phys
->dn_used
= space
>> DEV_BSHIFT
;
1773 dn
->dn_phys
->dn_used
= space
;
1774 dn
->dn_phys
->dn_flags
|= DNODE_FLAG_USED_BYTES
;
1776 mutex_exit(&dn
->dn_mtx
);
1780 * Call when we think we're going to write/free space in open context.
1781 * Be conservative (ie. OK to write less than this or free more than
1782 * this, but don't write more or free less).
1785 dnode_willuse_space(dnode_t
*dn
, int64_t space
, dmu_tx_t
*tx
)
1787 objset_t
*os
= dn
->dn_objset
;
1788 dsl_dataset_t
*ds
= os
->os_dsl_dataset
;
1791 space
= spa_get_asize(os
->os_spa
, space
);
1794 dsl_dir_willuse_space(ds
->ds_dir
, space
, tx
);
1796 dmu_tx_willuse_space(tx
, space
);
1800 * This function scans a block at the indicated "level" looking for
1801 * a hole or data (depending on 'flags'). If level > 0, then we are
1802 * scanning an indirect block looking at its pointers. If level == 0,
1803 * then we are looking at a block of dnodes. If we don't find what we
1804 * are looking for in the block, we return ESRCH. Otherwise, return
1805 * with *offset pointing to the beginning (if searching forwards) or
1806 * end (if searching backwards) of the range covered by the block
1807 * pointer we matched on (or dnode).
1809 * The basic search algorithm used below by dnode_next_offset() is to
1810 * use this function to search up the block tree (widen the search) until
1811 * we find something (i.e., we don't return ESRCH) and then search back
1812 * down the tree (narrow the search) until we reach our original search
1816 dnode_next_offset_level(dnode_t
*dn
, int flags
, uint64_t *offset
,
1817 int lvl
, uint64_t blkfill
, uint64_t txg
)
1819 dmu_buf_impl_t
*db
= NULL
;
1821 uint64_t epbs
= dn
->dn_phys
->dn_indblkshift
- SPA_BLKPTRSHIFT
;
1822 uint64_t epb
= 1ULL << epbs
;
1823 uint64_t minfill
, maxfill
;
1825 int i
, inc
, error
, span
;
1827 dprintf("probing object %llu offset %llx level %d of %u\n",
1828 dn
->dn_object
, *offset
, lvl
, dn
->dn_phys
->dn_nlevels
);
1830 hole
= ((flags
& DNODE_FIND_HOLE
) != 0);
1831 inc
= (flags
& DNODE_FIND_BACKWARDS
) ? -1 : 1;
1832 ASSERT(txg
== 0 || !hole
);
1834 if (lvl
== dn
->dn_phys
->dn_nlevels
) {
1836 epb
= dn
->dn_phys
->dn_nblkptr
;
1837 data
= dn
->dn_phys
->dn_blkptr
;
1839 uint64_t blkid
= dbuf_whichblock(dn
, *offset
) >> (epbs
* lvl
);
1840 error
= dbuf_hold_impl(dn
, lvl
, blkid
, TRUE
, FTAG
, &db
);
1842 if (error
!= ENOENT
)
1847 * This can only happen when we are searching up
1848 * the block tree for data. We don't really need to
1849 * adjust the offset, as we will just end up looking
1850 * at the pointer to this block in its parent, and its
1851 * going to be unallocated, so we will skip over it.
1855 error
= dbuf_read(db
, NULL
, DB_RF_CANFAIL
| DB_RF_HAVESTRUCT
);
1857 dbuf_rele(db
, FTAG
);
1860 data
= db
->db
.db_data
;
1864 (db
->db_blkptr
== NULL
|| db
->db_blkptr
->blk_birth
<= txg
)) {
1866 * This can only happen when we are searching up the tree
1867 * and these conditions mean that we need to keep climbing.
1870 } else if (lvl
== 0) {
1871 dnode_phys_t
*dnp
= data
;
1873 ASSERT(dn
->dn_type
== DMU_OT_DNODE
);
1875 for (i
= (*offset
>> span
) & (blkfill
- 1);
1876 i
>= 0 && i
< blkfill
; i
+= inc
) {
1877 if ((dnp
[i
].dn_type
== DMU_OT_NONE
) == hole
)
1879 *offset
+= (1ULL << span
) * inc
;
1881 if (i
< 0 || i
== blkfill
)
1884 blkptr_t
*bp
= data
;
1885 uint64_t start
= *offset
;
1886 span
= (lvl
- 1) * epbs
+ dn
->dn_datablkshift
;
1888 maxfill
= blkfill
<< ((lvl
- 1) * epbs
);
1895 *offset
= *offset
>> span
;
1896 for (i
= BF64_GET(*offset
, 0, epbs
);
1897 i
>= 0 && i
< epb
; i
+= inc
) {
1898 if (bp
[i
].blk_fill
>= minfill
&&
1899 bp
[i
].blk_fill
<= maxfill
&&
1900 (hole
|| bp
[i
].blk_birth
> txg
))
1902 if (inc
> 0 || *offset
> 0)
1905 *offset
= *offset
<< span
;
1907 /* traversing backwards; position offset at the end */
1908 ASSERT3U(*offset
, <=, start
);
1909 *offset
= MIN(*offset
+ (1ULL << span
) - 1, start
);
1910 } else if (*offset
< start
) {
1913 if (i
< 0 || i
>= epb
)
1918 dbuf_rele(db
, FTAG
);
1924 * Find the next hole, data, or sparse region at or after *offset.
1925 * The value 'blkfill' tells us how many items we expect to find
1926 * in an L0 data block; this value is 1 for normal objects,
1927 * DNODES_PER_BLOCK for the meta dnode, and some fraction of
1928 * DNODES_PER_BLOCK when searching for sparse regions thereof.
1932 * dnode_next_offset(dn, flags, offset, 1, 1, 0);
1933 * Finds the next/previous hole/data in a file.
1934 * Used in dmu_offset_next().
1936 * dnode_next_offset(mdn, flags, offset, 0, DNODES_PER_BLOCK, txg);
1937 * Finds the next free/allocated dnode an objset's meta-dnode.
1938 * Only finds objects that have new contents since txg (ie.
1939 * bonus buffer changes and content removal are ignored).
1940 * Used in dmu_object_next().
1942 * dnode_next_offset(mdn, DNODE_FIND_HOLE, offset, 2, DNODES_PER_BLOCK >> 2, 0);
1943 * Finds the next L2 meta-dnode bp that's at most 1/4 full.
1944 * Used in dmu_object_alloc().
1947 dnode_next_offset(dnode_t
*dn
, int flags
, uint64_t *offset
,
1948 int minlvl
, uint64_t blkfill
, uint64_t txg
)
1950 uint64_t initial_offset
= *offset
;
1954 if (!(flags
& DNODE_FIND_HAVELOCK
))
1955 rw_enter(&dn
->dn_struct_rwlock
, RW_READER
);
1957 if (dn
->dn_phys
->dn_nlevels
== 0) {
1962 if (dn
->dn_datablkshift
== 0) {
1963 if (*offset
< dn
->dn_datablksz
) {
1964 if (flags
& DNODE_FIND_HOLE
)
1965 *offset
= dn
->dn_datablksz
;
1972 maxlvl
= dn
->dn_phys
->dn_nlevels
;
1974 for (lvl
= minlvl
; lvl
<= maxlvl
; lvl
++) {
1975 error
= dnode_next_offset_level(dn
,
1976 flags
, offset
, lvl
, blkfill
, txg
);
1981 while (error
== 0 && --lvl
>= minlvl
) {
1982 error
= dnode_next_offset_level(dn
,
1983 flags
, offset
, lvl
, blkfill
, txg
);
1986 if (error
== 0 && (flags
& DNODE_FIND_BACKWARDS
?
1987 initial_offset
< *offset
: initial_offset
> *offset
))
1990 if (!(flags
& DNODE_FIND_HAVELOCK
))
1991 rw_exit(&dn
->dn_struct_rwlock
);