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]
23 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
24 * Copyright (c) 2012, 2014 by Delphix. All rights reserved.
27 #include <sys/zfs_context.h>
29 #include <sys/dnode.h>
31 #include <sys/dmu_tx.h>
32 #include <sys/dmu_objset.h>
33 #include <sys/dsl_dataset.h>
35 #include <sys/range_tree.h>
36 #include <sys/zfeature.h>
39 dnode_increase_indirection(dnode_t *dn, dmu_tx_t *tx)
42 int txgoff = tx->tx_txg & TXG_MASK;
43 int nblkptr = dn->dn_phys->dn_nblkptr;
44 int old_toplvl = dn->dn_phys->dn_nlevels - 1;
45 int new_level = dn->dn_next_nlevels[txgoff];
48 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
50 /* this dnode can't be paged out because it's dirty */
51 ASSERT(dn->dn_phys->dn_type != DMU_OT_NONE);
52 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
53 ASSERT(new_level > 1 && dn->dn_phys->dn_nlevels > 0);
55 db = dbuf_hold_level(dn, dn->dn_phys->dn_nlevels, 0, FTAG);
58 dn->dn_phys->dn_nlevels = new_level;
59 dprintf("os=%p obj=%llu, increase to %d\n", dn->dn_objset,
60 dn->dn_object, dn->dn_phys->dn_nlevels);
62 /* check for existing blkptrs in the dnode */
63 for (i = 0; i < nblkptr; i++)
64 if (!BP_IS_HOLE(&dn->dn_phys->dn_blkptr[i]))
67 /* transfer dnode's block pointers to new indirect block */
68 (void) dbuf_read(db, NULL, DB_RF_MUST_SUCCEED|DB_RF_HAVESTRUCT);
69 ASSERT(db->db.db_data);
70 ASSERT(arc_released(db->db_buf));
71 ASSERT3U(sizeof (blkptr_t) * nblkptr, <=, db->db.db_size);
72 bcopy(dn->dn_phys->dn_blkptr, db->db.db_data,
73 sizeof (blkptr_t) * nblkptr);
74 arc_buf_freeze(db->db_buf);
77 /* set dbuf's parent pointers to new indirect buf */
78 for (i = 0; i < nblkptr; i++) {
79 dmu_buf_impl_t *child = dbuf_find(dn, old_toplvl, i);
84 DB_DNODE_ENTER(child);
85 ASSERT3P(DB_DNODE(child), ==, dn);
88 if (child->db_parent && child->db_parent != dn->dn_dbuf) {
89 ASSERT(child->db_parent->db_level == db->db_level);
90 ASSERT(child->db_blkptr !=
91 &dn->dn_phys->dn_blkptr[child->db_blkid]);
92 mutex_exit(&child->db_mtx);
95 ASSERT(child->db_parent == NULL ||
96 child->db_parent == dn->dn_dbuf);
98 child->db_parent = db;
99 dbuf_add_ref(db, child);
101 child->db_blkptr = (blkptr_t *)db->db.db_data + i;
103 child->db_blkptr = NULL;
104 dprintf_dbuf_bp(child, child->db_blkptr,
105 "changed db_blkptr to new indirect %s", "");
107 mutex_exit(&child->db_mtx);
110 bzero(dn->dn_phys->dn_blkptr, sizeof (blkptr_t) * nblkptr);
114 rw_exit(&dn->dn_struct_rwlock);
118 free_blocks(dnode_t *dn, blkptr_t *bp, int num, dmu_tx_t *tx)
120 dsl_dataset_t *ds = dn->dn_objset->os_dsl_dataset;
121 uint64_t bytesfreed = 0;
123 dprintf("ds=%p obj=%llx num=%d\n", ds, dn->dn_object, num);
125 for (int i = 0; i < num; i++, bp++) {
129 bytesfreed += dsl_dataset_block_kill(ds, bp, tx, B_FALSE);
130 ASSERT3U(bytesfreed, <=, DN_USED_BYTES(dn->dn_phys));
133 * Save some useful information on the holes being
134 * punched, including logical size, type, and indirection
135 * level. Retaining birth time enables detection of when
136 * holes are punched for reducing the number of free
137 * records transmitted during a zfs send.
140 uint64_t lsize = BP_GET_LSIZE(bp);
141 dmu_object_type_t type = BP_GET_TYPE(bp);
142 uint64_t lvl = BP_GET_LEVEL(bp);
144 bzero(bp, sizeof (blkptr_t));
146 if (spa_feature_is_active(dn->dn_objset->os_spa,
147 SPA_FEATURE_HOLE_BIRTH)) {
148 BP_SET_LSIZE(bp, lsize);
149 BP_SET_TYPE(bp, type);
150 BP_SET_LEVEL(bp, lvl);
151 BP_SET_BIRTH(bp, dmu_tx_get_txg(tx), 0);
154 dnode_diduse_space(dn, -bytesfreed);
159 free_verify(dmu_buf_impl_t *db, uint64_t start, uint64_t end, dmu_tx_t *tx)
163 uint64_t txg = tx->tx_txg;
168 epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
169 off = start - (db->db_blkid * 1<<epbs);
170 num = end - start + 1;
172 ASSERT3U(off, >=, 0);
173 ASSERT3U(num, >=, 0);
174 ASSERT3U(db->db_level, >, 0);
175 ASSERT3U(db->db.db_size, ==, 1 << dn->dn_phys->dn_indblkshift);
176 ASSERT3U(off+num, <=, db->db.db_size >> SPA_BLKPTRSHIFT);
177 ASSERT(db->db_blkptr != NULL);
179 for (i = off; i < off+num; i++) {
181 dmu_buf_impl_t *child;
182 dbuf_dirty_record_t *dr;
185 ASSERT(db->db_level == 1);
187 rw_enter(&dn->dn_struct_rwlock, RW_READER);
188 err = dbuf_hold_impl(dn, db->db_level-1,
189 (db->db_blkid << epbs) + i, TRUE, FTAG, &child);
190 rw_exit(&dn->dn_struct_rwlock);
194 ASSERT(child->db_level == 0);
195 dr = child->db_last_dirty;
196 while (dr && dr->dr_txg > txg)
198 ASSERT(dr == NULL || dr->dr_txg == txg);
200 /* data_old better be zeroed */
202 buf = dr->dt.dl.dr_data->b_data;
203 for (j = 0; j < child->db.db_size >> 3; j++) {
205 panic("freed data not zero: "
206 "child=%p i=%d off=%d num=%d\n",
207 (void *)child, i, off, num);
213 * db_data better be zeroed unless it's dirty in a
216 mutex_enter(&child->db_mtx);
217 buf = child->db.db_data;
218 if (buf != NULL && child->db_state != DB_FILL &&
219 child->db_last_dirty == NULL) {
220 for (j = 0; j < child->db.db_size >> 3; j++) {
222 panic("freed data not zero: "
223 "child=%p i=%d off=%d num=%d\n",
224 (void *)child, i, off, num);
228 mutex_exit(&child->db_mtx);
230 dbuf_rele(child, FTAG);
237 free_children(dmu_buf_impl_t *db, uint64_t blkid, uint64_t nblks,
242 dmu_buf_impl_t *subdb;
243 uint64_t start, end, dbstart, dbend, i;
247 * There is a small possibility that this block will not be cached:
248 * 1 - if level > 1 and there are no children with level <= 1
249 * 2 - if this block was evicted since we read it from
250 * dmu_tx_hold_free().
252 if (db->db_state != DB_CACHED)
253 (void) dbuf_read(db, NULL, DB_RF_MUST_SUCCEED);
260 epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
261 shift = (db->db_level - 1) * epbs;
262 dbstart = db->db_blkid << epbs;
263 start = blkid >> shift;
264 if (dbstart < start) {
265 bp += start - dbstart;
269 dbend = ((db->db_blkid + 1) << epbs) - 1;
270 end = (blkid + nblks - 1) >> shift;
274 ASSERT3U(start, <=, end);
276 if (db->db_level == 1) {
277 FREE_VERIFY(db, start, end, tx);
278 free_blocks(dn, bp, end-start+1, tx);
280 for (i = start; i <= end; i++, bp++) {
283 rw_enter(&dn->dn_struct_rwlock, RW_READER);
284 VERIFY0(dbuf_hold_impl(dn, db->db_level - 1,
285 i, B_TRUE, FTAG, &subdb));
286 rw_exit(&dn->dn_struct_rwlock);
287 ASSERT3P(bp, ==, subdb->db_blkptr);
289 free_children(subdb, blkid, nblks, tx);
290 dbuf_rele(subdb, FTAG);
294 /* If this whole block is free, free ourself too. */
295 for (i = 0, bp = db->db.db_data; i < 1 << epbs; i++, bp++) {
299 if (i == 1 << epbs) {
300 /* didn't find any non-holes */
301 bzero(db->db.db_data, db->db.db_size);
302 free_blocks(dn, db->db_blkptr, 1, tx);
305 * Partial block free; must be marked dirty so that it
306 * will be written out.
308 ASSERT(db->db_dirtycnt > 0);
312 arc_buf_freeze(db->db_buf);
316 * Traverse the indicated range of the provided file
317 * and "free" all the blocks contained there.
320 dnode_sync_free_range_impl(dnode_t *dn, uint64_t blkid, uint64_t nblks,
323 blkptr_t *bp = dn->dn_phys->dn_blkptr;
324 int dnlevel = dn->dn_phys->dn_nlevels;
325 boolean_t trunc = B_FALSE;
327 if (blkid > dn->dn_phys->dn_maxblkid)
330 ASSERT(dn->dn_phys->dn_maxblkid < UINT64_MAX);
331 if (blkid + nblks > dn->dn_phys->dn_maxblkid) {
332 nblks = dn->dn_phys->dn_maxblkid - blkid + 1;
336 /* There are no indirect blocks in the object */
338 if (blkid >= dn->dn_phys->dn_nblkptr) {
339 /* this range was never made persistent */
342 ASSERT3U(blkid + nblks, <=, dn->dn_phys->dn_nblkptr);
343 free_blocks(dn, bp + blkid, nblks, tx);
345 int shift = (dnlevel - 1) *
346 (dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT);
347 int start = blkid >> shift;
348 int end = (blkid + nblks - 1) >> shift;
351 ASSERT(start < dn->dn_phys->dn_nblkptr);
353 for (int i = start; i <= end; i++, bp++) {
356 rw_enter(&dn->dn_struct_rwlock, RW_READER);
357 VERIFY0(dbuf_hold_impl(dn, dnlevel - 1, i,
359 rw_exit(&dn->dn_struct_rwlock);
361 free_children(db, blkid, nblks, tx);
367 dn->dn_phys->dn_maxblkid = blkid == 0 ? 0 : blkid - 1;
369 uint64_t off = (dn->dn_phys->dn_maxblkid + 1) *
370 (dn->dn_phys->dn_datablkszsec << SPA_MINBLOCKSHIFT);
371 ASSERT(off < dn->dn_phys->dn_maxblkid ||
372 dn->dn_phys->dn_maxblkid == 0 ||
373 dnode_next_offset(dn, 0, &off, 1, 1, 0) != 0);
377 typedef struct dnode_sync_free_range_arg {
378 dnode_t *dsfra_dnode;
380 } dnode_sync_free_range_arg_t;
383 dnode_sync_free_range(void *arg, uint64_t blkid, uint64_t nblks)
385 dnode_sync_free_range_arg_t *dsfra = arg;
386 dnode_t *dn = dsfra->dsfra_dnode;
388 mutex_exit(&dn->dn_mtx);
389 dnode_sync_free_range_impl(dn, blkid, nblks, dsfra->dsfra_tx);
390 mutex_enter(&dn->dn_mtx);
394 * Try to kick all the dnode's dbufs out of the cache...
397 dnode_evict_dbufs(dnode_t *dn)
403 dmu_buf_impl_t *db, *db_next;
404 int evicting = FALSE;
407 mutex_enter(&dn->dn_dbufs_mtx);
408 for (db = avl_first(&dn->dn_dbufs); db != NULL; db = db_next) {
409 db_next = AVL_NEXT(&dn->dn_dbufs, db);
412 ASSERT3P(DB_DNODE(db), ==, dn);
416 mutex_enter(&db->db_mtx);
417 if (db->db_state == DB_EVICTING) {
420 mutex_exit(&db->db_mtx);
421 } else if (refcount_is_zero(&db->db_holds)) {
423 dbuf_clear(db); /* exits db_mtx for us */
425 mutex_exit(&db->db_mtx);
430 * NB: we need to drop dn_dbufs_mtx between passes so
431 * that any DB_EVICTING dbufs can make progress.
432 * Ideally, we would have some cv we could wait on, but
433 * since we don't, just wait a bit to give the other
434 * thread a chance to run.
436 mutex_exit(&dn->dn_dbufs_mtx);
440 ASSERT(pass < 100); /* sanity check */
443 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
444 if (dn->dn_bonus && refcount_is_zero(&dn->dn_bonus->db_holds)) {
445 mutex_enter(&dn->dn_bonus->db_mtx);
446 dbuf_evict(dn->dn_bonus);
449 rw_exit(&dn->dn_struct_rwlock);
453 dnode_undirty_dbufs(list_t *list)
455 dbuf_dirty_record_t *dr;
457 while (dr = list_head(list)) {
458 dmu_buf_impl_t *db = dr->dr_dbuf;
459 uint64_t txg = dr->dr_txg;
461 if (db->db_level != 0)
462 dnode_undirty_dbufs(&dr->dt.di.dr_children);
464 mutex_enter(&db->db_mtx);
465 /* XXX - use dbuf_undirty()? */
466 list_remove(list, dr);
467 ASSERT(db->db_last_dirty == dr);
468 db->db_last_dirty = NULL;
469 db->db_dirtycnt -= 1;
470 if (db->db_level == 0) {
471 ASSERT(db->db_blkid == DMU_BONUS_BLKID ||
472 dr->dt.dl.dr_data == db->db_buf);
475 mutex_destroy(&dr->dt.di.dr_mtx);
476 list_destroy(&dr->dt.di.dr_children);
478 kmem_free(dr, sizeof (dbuf_dirty_record_t));
479 dbuf_rele_and_unlock(db, (void *)(uintptr_t)txg);
484 dnode_sync_free(dnode_t *dn, dmu_tx_t *tx)
486 int txgoff = tx->tx_txg & TXG_MASK;
488 ASSERT(dmu_tx_is_syncing(tx));
491 * Our contents should have been freed in dnode_sync() by the
492 * free range record inserted by the caller of dnode_free().
494 ASSERT0(DN_USED_BYTES(dn->dn_phys));
495 ASSERT(BP_IS_HOLE(dn->dn_phys->dn_blkptr));
497 dnode_undirty_dbufs(&dn->dn_dirty_records[txgoff]);
498 dnode_evict_dbufs(dn);
499 ASSERT(avl_is_empty(&dn->dn_dbufs));
500 ASSERT3P(dn->dn_bonus, ==, NULL);
503 * XXX - It would be nice to assert this, but we may still
504 * have residual holds from async evictions from the arc...
506 * zfs_obj_to_path() also depends on this being
509 * ASSERT3U(refcount_count(&dn->dn_holds), ==, 1);
512 /* Undirty next bits */
513 dn->dn_next_nlevels[txgoff] = 0;
514 dn->dn_next_indblkshift[txgoff] = 0;
515 dn->dn_next_blksz[txgoff] = 0;
517 /* ASSERT(blkptrs are zero); */
518 ASSERT(dn->dn_phys->dn_type != DMU_OT_NONE);
519 ASSERT(dn->dn_type != DMU_OT_NONE);
521 ASSERT(dn->dn_free_txg > 0);
522 if (dn->dn_allocated_txg != dn->dn_free_txg)
523 dmu_buf_will_dirty(&dn->dn_dbuf->db, tx);
524 bzero(dn->dn_phys, sizeof (dnode_phys_t));
526 mutex_enter(&dn->dn_mtx);
527 dn->dn_type = DMU_OT_NONE;
529 dn->dn_allocated_txg = 0;
531 dn->dn_have_spill = B_FALSE;
532 mutex_exit(&dn->dn_mtx);
534 ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT);
536 dnode_rele(dn, (void *)(uintptr_t)tx->tx_txg);
538 * Now that we've released our hold, the dnode may
539 * be evicted, so we musn't access it.
544 * Write out the dnode's dirty buffers.
547 dnode_sync(dnode_t *dn, dmu_tx_t *tx)
549 dnode_phys_t *dnp = dn->dn_phys;
550 int txgoff = tx->tx_txg & TXG_MASK;
551 list_t *list = &dn->dn_dirty_records[txgoff];
552 static const dnode_phys_t zerodn = { 0 };
553 boolean_t kill_spill = B_FALSE;
555 ASSERT(dmu_tx_is_syncing(tx));
556 ASSERT(dnp->dn_type != DMU_OT_NONE || dn->dn_allocated_txg);
557 ASSERT(dnp->dn_type != DMU_OT_NONE ||
558 bcmp(dnp, &zerodn, DNODE_SIZE) == 0);
561 ASSERT(dn->dn_dbuf == NULL || arc_released(dn->dn_dbuf->db_buf));
563 if (dmu_objset_userused_enabled(dn->dn_objset) &&
564 !DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
565 mutex_enter(&dn->dn_mtx);
566 dn->dn_oldused = DN_USED_BYTES(dn->dn_phys);
567 dn->dn_oldflags = dn->dn_phys->dn_flags;
568 dn->dn_phys->dn_flags |= DNODE_FLAG_USERUSED_ACCOUNTED;
569 mutex_exit(&dn->dn_mtx);
570 dmu_objset_userquota_get_ids(dn, B_FALSE, tx);
572 /* Once we account for it, we should always account for it. */
573 ASSERT(!(dn->dn_phys->dn_flags &
574 DNODE_FLAG_USERUSED_ACCOUNTED));
577 mutex_enter(&dn->dn_mtx);
578 if (dn->dn_allocated_txg == tx->tx_txg) {
579 /* The dnode is newly allocated or reallocated */
580 if (dnp->dn_type == DMU_OT_NONE) {
581 /* this is a first alloc, not a realloc */
583 dnp->dn_nblkptr = dn->dn_nblkptr;
586 dnp->dn_type = dn->dn_type;
587 dnp->dn_bonustype = dn->dn_bonustype;
588 dnp->dn_bonuslen = dn->dn_bonuslen;
590 ASSERT(dnp->dn_nlevels > 1 ||
591 BP_IS_HOLE(&dnp->dn_blkptr[0]) ||
592 BP_IS_EMBEDDED(&dnp->dn_blkptr[0]) ||
593 BP_GET_LSIZE(&dnp->dn_blkptr[0]) ==
594 dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT);
595 ASSERT(dnp->dn_nlevels < 2 ||
596 BP_IS_HOLE(&dnp->dn_blkptr[0]) ||
597 BP_GET_LSIZE(&dnp->dn_blkptr[0]) == 1 << dnp->dn_indblkshift);
599 if (dn->dn_next_type[txgoff] != 0) {
600 dnp->dn_type = dn->dn_type;
601 dn->dn_next_type[txgoff] = 0;
604 if (dn->dn_next_blksz[txgoff] != 0) {
605 ASSERT(P2PHASE(dn->dn_next_blksz[txgoff],
606 SPA_MINBLOCKSIZE) == 0);
607 ASSERT(BP_IS_HOLE(&dnp->dn_blkptr[0]) ||
608 dn->dn_maxblkid == 0 || list_head(list) != NULL ||
609 dn->dn_next_blksz[txgoff] >> SPA_MINBLOCKSHIFT ==
610 dnp->dn_datablkszsec ||
611 range_tree_space(dn->dn_free_ranges[txgoff]) != 0);
612 dnp->dn_datablkszsec =
613 dn->dn_next_blksz[txgoff] >> SPA_MINBLOCKSHIFT;
614 dn->dn_next_blksz[txgoff] = 0;
617 if (dn->dn_next_bonuslen[txgoff] != 0) {
618 if (dn->dn_next_bonuslen[txgoff] == DN_ZERO_BONUSLEN)
619 dnp->dn_bonuslen = 0;
621 dnp->dn_bonuslen = dn->dn_next_bonuslen[txgoff];
622 ASSERT(dnp->dn_bonuslen <= DN_MAX_BONUSLEN);
623 dn->dn_next_bonuslen[txgoff] = 0;
626 if (dn->dn_next_bonustype[txgoff] != 0) {
627 ASSERT(DMU_OT_IS_VALID(dn->dn_next_bonustype[txgoff]));
628 dnp->dn_bonustype = dn->dn_next_bonustype[txgoff];
629 dn->dn_next_bonustype[txgoff] = 0;
632 boolean_t freeing_dnode = dn->dn_free_txg > 0 &&
633 dn->dn_free_txg <= tx->tx_txg;
636 * Remove the spill block if we have been explicitly asked to
637 * remove it, or if the object is being removed.
639 if (dn->dn_rm_spillblk[txgoff] || freeing_dnode) {
640 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR)
642 dn->dn_rm_spillblk[txgoff] = 0;
645 if (dn->dn_next_indblkshift[txgoff] != 0) {
646 ASSERT(dnp->dn_nlevels == 1);
647 dnp->dn_indblkshift = dn->dn_next_indblkshift[txgoff];
648 dn->dn_next_indblkshift[txgoff] = 0;
652 * Just take the live (open-context) values for checksum and compress.
653 * Strictly speaking it's a future leak, but nothing bad happens if we
654 * start using the new checksum or compress algorithm a little early.
656 dnp->dn_checksum = dn->dn_checksum;
657 dnp->dn_compress = dn->dn_compress;
659 mutex_exit(&dn->dn_mtx);
662 free_blocks(dn, &dn->dn_phys->dn_spill, 1, tx);
663 mutex_enter(&dn->dn_mtx);
664 dnp->dn_flags &= ~DNODE_FLAG_SPILL_BLKPTR;
665 mutex_exit(&dn->dn_mtx);
668 /* process all the "freed" ranges in the file */
669 if (dn->dn_free_ranges[txgoff] != NULL) {
670 dnode_sync_free_range_arg_t dsfra;
671 dsfra.dsfra_dnode = dn;
673 mutex_enter(&dn->dn_mtx);
674 range_tree_vacate(dn->dn_free_ranges[txgoff],
675 dnode_sync_free_range, &dsfra);
676 range_tree_destroy(dn->dn_free_ranges[txgoff]);
677 dn->dn_free_ranges[txgoff] = NULL;
678 mutex_exit(&dn->dn_mtx);
682 dnode_sync_free(dn, tx);
686 if (dn->dn_next_nlevels[txgoff]) {
687 dnode_increase_indirection(dn, tx);
688 dn->dn_next_nlevels[txgoff] = 0;
691 if (dn->dn_next_nblkptr[txgoff]) {
692 /* this should only happen on a realloc */
693 ASSERT(dn->dn_allocated_txg == tx->tx_txg);
694 if (dn->dn_next_nblkptr[txgoff] > dnp->dn_nblkptr) {
695 /* zero the new blkptrs we are gaining */
696 bzero(dnp->dn_blkptr + dnp->dn_nblkptr,
698 (dn->dn_next_nblkptr[txgoff] - dnp->dn_nblkptr));
702 ASSERT(dn->dn_next_nblkptr[txgoff] < dnp->dn_nblkptr);
703 /* the blkptrs we are losing better be unallocated */
704 for (i = dn->dn_next_nblkptr[txgoff];
705 i < dnp->dn_nblkptr; i++)
706 ASSERT(BP_IS_HOLE(&dnp->dn_blkptr[i]));
709 mutex_enter(&dn->dn_mtx);
710 dnp->dn_nblkptr = dn->dn_next_nblkptr[txgoff];
711 dn->dn_next_nblkptr[txgoff] = 0;
712 mutex_exit(&dn->dn_mtx);
715 dbuf_sync_list(list, tx);
717 if (!DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
718 ASSERT3P(list_head(list), ==, NULL);
719 dnode_rele(dn, (void *)(uintptr_t)tx->tx_txg);
723 * Although we have dropped our reference to the dnode, it
724 * can't be evicted until its written, and we haven't yet
725 * initiated the IO for the dnode's dbuf.