4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
24 * Copyright (c) 2012, 2014 by Delphix. All rights reserved.
25 * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
26 * Copyright (c) 2013, Joyent, Inc. All rights reserved.
29 #include <sys/zfs_context.h>
31 #include <sys/dmu_send.h>
32 #include <sys/dmu_impl.h>
34 #include <sys/dmu_objset.h>
35 #include <sys/dsl_dataset.h>
36 #include <sys/dsl_dir.h>
37 #include <sys/dmu_tx.h>
40 #include <sys/dmu_zfetch.h>
42 #include <sys/sa_impl.h>
43 #include <sys/zfeature.h>
44 #include <sys/blkptr.h>
45 #include <sys/range_tree.h>
48 * Number of times that zfs_free_range() took the slow path while doing
49 * a zfs receive. A nonzero value indicates a potential performance problem.
51 uint64_t zfs_free_range_recv_miss;
53 static void dbuf_destroy(dmu_buf_impl_t *db);
54 static boolean_t dbuf_undirty(dmu_buf_impl_t *db, dmu_tx_t *tx);
55 static void dbuf_write(dbuf_dirty_record_t *dr, arc_buf_t *data, dmu_tx_t *tx);
58 * Global data structures and functions for the dbuf cache.
60 static kmem_cache_t *dbuf_cache;
64 dbuf_cons(void *vdb, void *unused, int kmflag)
66 dmu_buf_impl_t *db = vdb;
67 bzero(db, sizeof (dmu_buf_impl_t));
69 mutex_init(&db->db_mtx, NULL, MUTEX_DEFAULT, NULL);
70 cv_init(&db->db_changed, NULL, CV_DEFAULT, NULL);
71 refcount_create(&db->db_holds);
77 dbuf_dest(void *vdb, void *unused)
79 dmu_buf_impl_t *db = vdb;
80 mutex_destroy(&db->db_mtx);
81 cv_destroy(&db->db_changed);
82 refcount_destroy(&db->db_holds);
86 * dbuf hash table routines
88 static dbuf_hash_table_t dbuf_hash_table;
90 static uint64_t dbuf_hash_count;
93 dbuf_hash(void *os, uint64_t obj, uint8_t lvl, uint64_t blkid)
95 uintptr_t osv = (uintptr_t)os;
98 ASSERT(zfs_crc64_table[128] == ZFS_CRC64_POLY);
99 crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (lvl)) & 0xFF];
100 crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (osv >> 6)) & 0xFF];
101 crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (obj >> 0)) & 0xFF];
102 crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (obj >> 8)) & 0xFF];
103 crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (blkid >> 0)) & 0xFF];
104 crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (blkid >> 8)) & 0xFF];
106 crc ^= (osv>>14) ^ (obj>>16) ^ (blkid>>16);
111 #define DBUF_HASH(os, obj, level, blkid) dbuf_hash(os, obj, level, blkid);
113 #define DBUF_EQUAL(dbuf, os, obj, level, blkid) \
114 ((dbuf)->db.db_object == (obj) && \
115 (dbuf)->db_objset == (os) && \
116 (dbuf)->db_level == (level) && \
117 (dbuf)->db_blkid == (blkid))
120 dbuf_find(dnode_t *dn, uint8_t level, uint64_t blkid)
122 dbuf_hash_table_t *h = &dbuf_hash_table;
123 objset_t *os = dn->dn_objset;
124 uint64_t obj = dn->dn_object;
125 uint64_t hv = DBUF_HASH(os, obj, level, blkid);
126 uint64_t idx = hv & h->hash_table_mask;
129 mutex_enter(DBUF_HASH_MUTEX(h, idx));
130 for (db = h->hash_table[idx]; db != NULL; db = db->db_hash_next) {
131 if (DBUF_EQUAL(db, os, obj, level, blkid)) {
132 mutex_enter(&db->db_mtx);
133 if (db->db_state != DB_EVICTING) {
134 mutex_exit(DBUF_HASH_MUTEX(h, idx));
137 mutex_exit(&db->db_mtx);
140 mutex_exit(DBUF_HASH_MUTEX(h, idx));
145 * Insert an entry into the hash table. If there is already an element
146 * equal to elem in the hash table, then the already existing element
147 * will be returned and the new element will not be inserted.
148 * Otherwise returns NULL.
150 static dmu_buf_impl_t *
151 dbuf_hash_insert(dmu_buf_impl_t *db)
153 dbuf_hash_table_t *h = &dbuf_hash_table;
154 objset_t *os = db->db_objset;
155 uint64_t obj = db->db.db_object;
156 int level = db->db_level;
157 uint64_t blkid = db->db_blkid;
158 uint64_t hv = DBUF_HASH(os, obj, level, blkid);
159 uint64_t idx = hv & h->hash_table_mask;
162 mutex_enter(DBUF_HASH_MUTEX(h, idx));
163 for (dbf = h->hash_table[idx]; dbf != NULL; dbf = dbf->db_hash_next) {
164 if (DBUF_EQUAL(dbf, os, obj, level, blkid)) {
165 mutex_enter(&dbf->db_mtx);
166 if (dbf->db_state != DB_EVICTING) {
167 mutex_exit(DBUF_HASH_MUTEX(h, idx));
170 mutex_exit(&dbf->db_mtx);
174 mutex_enter(&db->db_mtx);
175 db->db_hash_next = h->hash_table[idx];
176 h->hash_table[idx] = db;
177 mutex_exit(DBUF_HASH_MUTEX(h, idx));
178 atomic_add_64(&dbuf_hash_count, 1);
184 * Remove an entry from the hash table. It must be in the EVICTING state.
187 dbuf_hash_remove(dmu_buf_impl_t *db)
189 dbuf_hash_table_t *h = &dbuf_hash_table;
190 uint64_t hv = DBUF_HASH(db->db_objset, db->db.db_object,
191 db->db_level, db->db_blkid);
192 uint64_t idx = hv & h->hash_table_mask;
193 dmu_buf_impl_t *dbf, **dbp;
196 * We musn't hold db_mtx to maintain lock ordering:
197 * DBUF_HASH_MUTEX > db_mtx.
199 ASSERT(refcount_is_zero(&db->db_holds));
200 ASSERT(db->db_state == DB_EVICTING);
201 ASSERT(!MUTEX_HELD(&db->db_mtx));
203 mutex_enter(DBUF_HASH_MUTEX(h, idx));
204 dbp = &h->hash_table[idx];
205 while ((dbf = *dbp) != db) {
206 dbp = &dbf->db_hash_next;
209 *dbp = db->db_hash_next;
210 db->db_hash_next = NULL;
211 mutex_exit(DBUF_HASH_MUTEX(h, idx));
212 atomic_add_64(&dbuf_hash_count, -1);
215 static arc_evict_func_t dbuf_do_evict;
218 dbuf_evict_user(dmu_buf_impl_t *db)
220 ASSERT(MUTEX_HELD(&db->db_mtx));
222 if (db->db_level != 0 || db->db_evict_func == NULL)
225 if (db->db_user_data_ptr_ptr)
226 *db->db_user_data_ptr_ptr = db->db.db_data;
227 db->db_evict_func(&db->db, db->db_user_ptr);
228 db->db_user_ptr = NULL;
229 db->db_user_data_ptr_ptr = NULL;
230 db->db_evict_func = NULL;
234 dbuf_is_metadata(dmu_buf_impl_t *db)
236 if (db->db_level > 0) {
239 boolean_t is_metadata;
242 is_metadata = DMU_OT_IS_METADATA(DB_DNODE(db)->dn_type);
245 return (is_metadata);
250 dbuf_evict(dmu_buf_impl_t *db)
252 ASSERT(MUTEX_HELD(&db->db_mtx));
253 ASSERT(db->db_buf == NULL);
254 ASSERT(db->db_data_pending == NULL);
263 uint64_t hsize = 1ULL << 16;
264 dbuf_hash_table_t *h = &dbuf_hash_table;
268 * The hash table is big enough to fill all of physical memory
269 * with an average 4K block size. The table will take up
270 * totalmem*sizeof(void*)/4K (i.e. 2MB/GB with 8-byte pointers).
272 while (hsize * 4096 < (uint64_t)physmem * PAGESIZE)
276 h->hash_table_mask = hsize - 1;
277 h->hash_table = kmem_zalloc(hsize * sizeof (void *), KM_NOSLEEP);
278 if (h->hash_table == NULL) {
279 /* XXX - we should really return an error instead of assert */
280 ASSERT(hsize > (1ULL << 10));
285 dbuf_cache = kmem_cache_create("dmu_buf_impl_t",
286 sizeof (dmu_buf_impl_t),
287 0, dbuf_cons, dbuf_dest, NULL, NULL, NULL, 0);
289 for (i = 0; i < DBUF_MUTEXES; i++)
290 mutex_init(&h->hash_mutexes[i], NULL, MUTEX_DEFAULT, NULL);
296 dbuf_hash_table_t *h = &dbuf_hash_table;
299 for (i = 0; i < DBUF_MUTEXES; i++)
300 mutex_destroy(&h->hash_mutexes[i]);
301 kmem_free(h->hash_table, (h->hash_table_mask + 1) * sizeof (void *));
302 kmem_cache_destroy(dbuf_cache);
311 dbuf_verify(dmu_buf_impl_t *db)
314 dbuf_dirty_record_t *dr;
316 ASSERT(MUTEX_HELD(&db->db_mtx));
318 if (!(zfs_flags & ZFS_DEBUG_DBUF_VERIFY))
321 ASSERT(db->db_objset != NULL);
325 ASSERT(db->db_parent == NULL);
326 ASSERT(db->db_blkptr == NULL);
328 ASSERT3U(db->db.db_object, ==, dn->dn_object);
329 ASSERT3P(db->db_objset, ==, dn->dn_objset);
330 ASSERT3U(db->db_level, <, dn->dn_nlevels);
331 ASSERT(db->db_blkid == DMU_BONUS_BLKID ||
332 db->db_blkid == DMU_SPILL_BLKID ||
333 !list_is_empty(&dn->dn_dbufs));
335 if (db->db_blkid == DMU_BONUS_BLKID) {
337 ASSERT3U(db->db.db_size, >=, dn->dn_bonuslen);
338 ASSERT3U(db->db.db_offset, ==, DMU_BONUS_BLKID);
339 } else if (db->db_blkid == DMU_SPILL_BLKID) {
341 ASSERT3U(db->db.db_size, >=, dn->dn_bonuslen);
342 ASSERT0(db->db.db_offset);
344 ASSERT3U(db->db.db_offset, ==, db->db_blkid * db->db.db_size);
347 for (dr = db->db_data_pending; dr != NULL; dr = dr->dr_next)
348 ASSERT(dr->dr_dbuf == db);
350 for (dr = db->db_last_dirty; dr != NULL; dr = dr->dr_next)
351 ASSERT(dr->dr_dbuf == db);
354 * We can't assert that db_size matches dn_datablksz because it
355 * can be momentarily different when another thread is doing
358 if (db->db_level == 0 && db->db.db_object == DMU_META_DNODE_OBJECT) {
359 dr = db->db_data_pending;
361 * It should only be modified in syncing context, so
362 * make sure we only have one copy of the data.
364 ASSERT(dr == NULL || dr->dt.dl.dr_data == db->db_buf);
367 /* verify db->db_blkptr */
369 if (db->db_parent == dn->dn_dbuf) {
370 /* db is pointed to by the dnode */
371 /* ASSERT3U(db->db_blkid, <, dn->dn_nblkptr); */
372 if (DMU_OBJECT_IS_SPECIAL(db->db.db_object))
373 ASSERT(db->db_parent == NULL);
375 ASSERT(db->db_parent != NULL);
376 if (db->db_blkid != DMU_SPILL_BLKID)
377 ASSERT3P(db->db_blkptr, ==,
378 &dn->dn_phys->dn_blkptr[db->db_blkid]);
380 /* db is pointed to by an indirect block */
381 int epb = db->db_parent->db.db_size >> SPA_BLKPTRSHIFT;
382 ASSERT3U(db->db_parent->db_level, ==, db->db_level+1);
383 ASSERT3U(db->db_parent->db.db_object, ==,
386 * dnode_grow_indblksz() can make this fail if we don't
387 * have the struct_rwlock. XXX indblksz no longer
388 * grows. safe to do this now?
390 if (RW_WRITE_HELD(&dn->dn_struct_rwlock)) {
391 ASSERT3P(db->db_blkptr, ==,
392 ((blkptr_t *)db->db_parent->db.db_data +
393 db->db_blkid % epb));
397 if ((db->db_blkptr == NULL || BP_IS_HOLE(db->db_blkptr)) &&
398 (db->db_buf == NULL || db->db_buf->b_data) &&
399 db->db.db_data && db->db_blkid != DMU_BONUS_BLKID &&
400 db->db_state != DB_FILL && !dn->dn_free_txg) {
402 * If the blkptr isn't set but they have nonzero data,
403 * it had better be dirty, otherwise we'll lose that
404 * data when we evict this buffer.
406 if (db->db_dirtycnt == 0) {
407 uint64_t *buf = db->db.db_data;
410 for (i = 0; i < db->db.db_size >> 3; i++) {
420 dbuf_update_data(dmu_buf_impl_t *db)
422 ASSERT(MUTEX_HELD(&db->db_mtx));
423 if (db->db_level == 0 && db->db_user_data_ptr_ptr) {
424 ASSERT(!refcount_is_zero(&db->db_holds));
425 *db->db_user_data_ptr_ptr = db->db.db_data;
430 dbuf_set_data(dmu_buf_impl_t *db, arc_buf_t *buf)
432 ASSERT(MUTEX_HELD(&db->db_mtx));
435 ASSERT(buf->b_data != NULL);
436 db->db.db_data = buf->b_data;
437 if (!arc_released(buf))
438 arc_set_callback(buf, dbuf_do_evict, db);
439 dbuf_update_data(db);
442 db->db.db_data = NULL;
443 if (db->db_state != DB_NOFILL)
444 db->db_state = DB_UNCACHED;
449 * Loan out an arc_buf for read. Return the loaned arc_buf.
452 dbuf_loan_arcbuf(dmu_buf_impl_t *db)
456 mutex_enter(&db->db_mtx);
457 if (arc_released(db->db_buf) || refcount_count(&db->db_holds) > 1) {
458 int blksz = db->db.db_size;
459 spa_t *spa = db->db_objset->os_spa;
461 mutex_exit(&db->db_mtx);
462 abuf = arc_loan_buf(spa, blksz);
463 bcopy(db->db.db_data, abuf->b_data, blksz);
466 arc_loan_inuse_buf(abuf, db);
467 dbuf_set_data(db, NULL);
468 mutex_exit(&db->db_mtx);
474 dbuf_whichblock(dnode_t *dn, uint64_t offset)
476 if (dn->dn_datablkshift) {
477 return (offset >> dn->dn_datablkshift);
479 ASSERT3U(offset, <, dn->dn_datablksz);
485 dbuf_read_done(zio_t *zio, arc_buf_t *buf, void *vdb)
487 dmu_buf_impl_t *db = vdb;
489 mutex_enter(&db->db_mtx);
490 ASSERT3U(db->db_state, ==, DB_READ);
492 * All reads are synchronous, so we must have a hold on the dbuf
494 ASSERT(refcount_count(&db->db_holds) > 0);
495 ASSERT(db->db_buf == NULL);
496 ASSERT(db->db.db_data == NULL);
497 if (db->db_level == 0 && db->db_freed_in_flight) {
498 /* we were freed in flight; disregard any error */
499 arc_release(buf, db);
500 bzero(buf->b_data, db->db.db_size);
502 db->db_freed_in_flight = FALSE;
503 dbuf_set_data(db, buf);
504 db->db_state = DB_CACHED;
505 } else if (zio == NULL || zio->io_error == 0) {
506 dbuf_set_data(db, buf);
507 db->db_state = DB_CACHED;
509 ASSERT(db->db_blkid != DMU_BONUS_BLKID);
510 ASSERT3P(db->db_buf, ==, NULL);
511 VERIFY(arc_buf_remove_ref(buf, db));
512 db->db_state = DB_UNCACHED;
514 cv_broadcast(&db->db_changed);
515 dbuf_rele_and_unlock(db, NULL);
519 dbuf_read_impl(dmu_buf_impl_t *db, zio_t *zio, uint32_t *flags)
523 uint32_t aflags = ARC_NOWAIT;
527 ASSERT(!refcount_is_zero(&db->db_holds));
528 /* We need the struct_rwlock to prevent db_blkptr from changing. */
529 ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock));
530 ASSERT(MUTEX_HELD(&db->db_mtx));
531 ASSERT(db->db_state == DB_UNCACHED);
532 ASSERT(db->db_buf == NULL);
534 if (db->db_blkid == DMU_BONUS_BLKID) {
535 int bonuslen = MIN(dn->dn_bonuslen, dn->dn_phys->dn_bonuslen);
537 ASSERT3U(bonuslen, <=, db->db.db_size);
538 db->db.db_data = zio_buf_alloc(DN_MAX_BONUSLEN);
539 arc_space_consume(DN_MAX_BONUSLEN, ARC_SPACE_OTHER);
540 if (bonuslen < DN_MAX_BONUSLEN)
541 bzero(db->db.db_data, DN_MAX_BONUSLEN);
543 bcopy(DN_BONUS(dn->dn_phys), db->db.db_data, bonuslen);
545 dbuf_update_data(db);
546 db->db_state = DB_CACHED;
547 mutex_exit(&db->db_mtx);
552 * Recheck BP_IS_HOLE() after dnode_block_freed() in case dnode_sync()
553 * processes the delete record and clears the bp while we are waiting
554 * for the dn_mtx (resulting in a "no" from block_freed).
556 if (db->db_blkptr == NULL || BP_IS_HOLE(db->db_blkptr) ||
557 (db->db_level == 0 && (dnode_block_freed(dn, db->db_blkid) ||
558 BP_IS_HOLE(db->db_blkptr)))) {
559 arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db);
562 dbuf_set_data(db, arc_buf_alloc(db->db_objset->os_spa,
563 db->db.db_size, db, type));
564 bzero(db->db.db_data, db->db.db_size);
565 db->db_state = DB_CACHED;
566 *flags |= DB_RF_CACHED;
567 mutex_exit(&db->db_mtx);
573 db->db_state = DB_READ;
574 mutex_exit(&db->db_mtx);
576 if (DBUF_IS_L2CACHEABLE(db))
577 aflags |= ARC_L2CACHE;
578 if (DBUF_IS_L2COMPRESSIBLE(db))
579 aflags |= ARC_L2COMPRESS;
581 SET_BOOKMARK(&zb, db->db_objset->os_dsl_dataset ?
582 db->db_objset->os_dsl_dataset->ds_object : DMU_META_OBJSET,
583 db->db.db_object, db->db_level, db->db_blkid);
585 dbuf_add_ref(db, NULL);
587 (void) arc_read(zio, db->db_objset->os_spa, db->db_blkptr,
588 dbuf_read_done, db, ZIO_PRIORITY_SYNC_READ,
589 (*flags & DB_RF_CANFAIL) ? ZIO_FLAG_CANFAIL : ZIO_FLAG_MUSTSUCCEED,
591 if (aflags & ARC_CACHED)
592 *flags |= DB_RF_CACHED;
596 dbuf_read(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags)
599 boolean_t havepzio = (zio != NULL);
604 * We don't have to hold the mutex to check db_state because it
605 * can't be freed while we have a hold on the buffer.
607 ASSERT(!refcount_is_zero(&db->db_holds));
609 if (db->db_state == DB_NOFILL)
610 return (SET_ERROR(EIO));
614 if ((flags & DB_RF_HAVESTRUCT) == 0)
615 rw_enter(&dn->dn_struct_rwlock, RW_READER);
617 prefetch = db->db_level == 0 && db->db_blkid != DMU_BONUS_BLKID &&
618 (flags & DB_RF_NOPREFETCH) == 0 && dn != NULL &&
619 DBUF_IS_CACHEABLE(db);
621 mutex_enter(&db->db_mtx);
622 if (db->db_state == DB_CACHED) {
623 mutex_exit(&db->db_mtx);
625 dmu_zfetch(&dn->dn_zfetch, db->db.db_offset,
626 db->db.db_size, TRUE);
627 if ((flags & DB_RF_HAVESTRUCT) == 0)
628 rw_exit(&dn->dn_struct_rwlock);
630 } else if (db->db_state == DB_UNCACHED) {
631 spa_t *spa = dn->dn_objset->os_spa;
634 zio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL);
635 dbuf_read_impl(db, zio, &flags);
637 /* dbuf_read_impl has dropped db_mtx for us */
640 dmu_zfetch(&dn->dn_zfetch, db->db.db_offset,
641 db->db.db_size, flags & DB_RF_CACHED);
643 if ((flags & DB_RF_HAVESTRUCT) == 0)
644 rw_exit(&dn->dn_struct_rwlock);
651 * Another reader came in while the dbuf was in flight
652 * between UNCACHED and CACHED. Either a writer will finish
653 * writing the buffer (sending the dbuf to CACHED) or the
654 * first reader's request will reach the read_done callback
655 * and send the dbuf to CACHED. Otherwise, a failure
656 * occurred and the dbuf went to UNCACHED.
658 mutex_exit(&db->db_mtx);
660 dmu_zfetch(&dn->dn_zfetch, db->db.db_offset,
661 db->db.db_size, TRUE);
662 if ((flags & DB_RF_HAVESTRUCT) == 0)
663 rw_exit(&dn->dn_struct_rwlock);
666 /* Skip the wait per the caller's request. */
667 mutex_enter(&db->db_mtx);
668 if ((flags & DB_RF_NEVERWAIT) == 0) {
669 while (db->db_state == DB_READ ||
670 db->db_state == DB_FILL) {
671 ASSERT(db->db_state == DB_READ ||
672 (flags & DB_RF_HAVESTRUCT) == 0);
673 cv_wait(&db->db_changed, &db->db_mtx);
675 if (db->db_state == DB_UNCACHED)
676 err = SET_ERROR(EIO);
678 mutex_exit(&db->db_mtx);
681 ASSERT(err || havepzio || db->db_state == DB_CACHED);
686 dbuf_noread(dmu_buf_impl_t *db)
688 ASSERT(!refcount_is_zero(&db->db_holds));
689 ASSERT(db->db_blkid != DMU_BONUS_BLKID);
690 mutex_enter(&db->db_mtx);
691 while (db->db_state == DB_READ || db->db_state == DB_FILL)
692 cv_wait(&db->db_changed, &db->db_mtx);
693 if (db->db_state == DB_UNCACHED) {
694 arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db);
695 spa_t *spa = db->db_objset->os_spa;
697 ASSERT(db->db_buf == NULL);
698 ASSERT(db->db.db_data == NULL);
699 dbuf_set_data(db, arc_buf_alloc(spa, db->db.db_size, db, type));
700 db->db_state = DB_FILL;
701 } else if (db->db_state == DB_NOFILL) {
702 dbuf_set_data(db, NULL);
704 ASSERT3U(db->db_state, ==, DB_CACHED);
706 mutex_exit(&db->db_mtx);
710 * This is our just-in-time copy function. It makes a copy of
711 * buffers, that have been modified in a previous transaction
712 * group, before we modify them in the current active group.
714 * This function is used in two places: when we are dirtying a
715 * buffer for the first time in a txg, and when we are freeing
716 * a range in a dnode that includes this buffer.
718 * Note that when we are called from dbuf_free_range() we do
719 * not put a hold on the buffer, we just traverse the active
720 * dbuf list for the dnode.
723 dbuf_fix_old_data(dmu_buf_impl_t *db, uint64_t txg)
725 dbuf_dirty_record_t *dr = db->db_last_dirty;
727 ASSERT(MUTEX_HELD(&db->db_mtx));
728 ASSERT(db->db.db_data != NULL);
729 ASSERT(db->db_level == 0);
730 ASSERT(db->db.db_object != DMU_META_DNODE_OBJECT);
733 (dr->dt.dl.dr_data !=
734 ((db->db_blkid == DMU_BONUS_BLKID) ? db->db.db_data : db->db_buf)))
738 * If the last dirty record for this dbuf has not yet synced
739 * and its referencing the dbuf data, either:
740 * reset the reference to point to a new copy,
741 * or (if there a no active holders)
742 * just null out the current db_data pointer.
744 ASSERT(dr->dr_txg >= txg - 2);
745 if (db->db_blkid == DMU_BONUS_BLKID) {
746 /* Note that the data bufs here are zio_bufs */
747 dr->dt.dl.dr_data = zio_buf_alloc(DN_MAX_BONUSLEN);
748 arc_space_consume(DN_MAX_BONUSLEN, ARC_SPACE_OTHER);
749 bcopy(db->db.db_data, dr->dt.dl.dr_data, DN_MAX_BONUSLEN);
750 } else if (refcount_count(&db->db_holds) > db->db_dirtycnt) {
751 int size = db->db.db_size;
752 arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db);
753 spa_t *spa = db->db_objset->os_spa;
755 dr->dt.dl.dr_data = arc_buf_alloc(spa, size, db, type);
756 bcopy(db->db.db_data, dr->dt.dl.dr_data->b_data, size);
758 dbuf_set_data(db, NULL);
763 dbuf_unoverride(dbuf_dirty_record_t *dr)
765 dmu_buf_impl_t *db = dr->dr_dbuf;
766 blkptr_t *bp = &dr->dt.dl.dr_overridden_by;
767 uint64_t txg = dr->dr_txg;
769 ASSERT(MUTEX_HELD(&db->db_mtx));
770 ASSERT(dr->dt.dl.dr_override_state != DR_IN_DMU_SYNC);
771 ASSERT(db->db_level == 0);
773 if (db->db_blkid == DMU_BONUS_BLKID ||
774 dr->dt.dl.dr_override_state == DR_NOT_OVERRIDDEN)
777 ASSERT(db->db_data_pending != dr);
779 /* free this block */
780 if (!BP_IS_HOLE(bp) && !dr->dt.dl.dr_nopwrite)
781 zio_free(db->db_objset->os_spa, txg, bp);
783 dr->dt.dl.dr_override_state = DR_NOT_OVERRIDDEN;
784 dr->dt.dl.dr_nopwrite = B_FALSE;
787 * Release the already-written buffer, so we leave it in
788 * a consistent dirty state. Note that all callers are
789 * modifying the buffer, so they will immediately do
790 * another (redundant) arc_release(). Therefore, leave
791 * the buf thawed to save the effort of freezing &
792 * immediately re-thawing it.
794 arc_release(dr->dt.dl.dr_data, db);
798 * Evict (if its unreferenced) or clear (if its referenced) any level-0
799 * data blocks in the free range, so that any future readers will find
802 * This is a no-op if the dataset is in the middle of an incremental
803 * receive; see comment below for details.
806 dbuf_free_range(dnode_t *dn, uint64_t start, uint64_t end, dmu_tx_t *tx)
808 dmu_buf_impl_t *db, *db_next;
809 uint64_t txg = tx->tx_txg;
811 if (end > dn->dn_maxblkid && (end != DMU_SPILL_BLKID))
812 end = dn->dn_maxblkid;
813 dprintf_dnode(dn, "start=%llu end=%llu\n", start, end);
815 mutex_enter(&dn->dn_dbufs_mtx);
816 if (start >= dn->dn_unlisted_l0_blkid * dn->dn_datablksz) {
817 /* There can't be any dbufs in this range; no need to search. */
818 mutex_exit(&dn->dn_dbufs_mtx);
820 } else if (dmu_objset_is_receiving(dn->dn_objset)) {
822 * If we are receiving, we expect there to be no dbufs in
823 * the range to be freed, because receive modifies each
824 * block at most once, and in offset order. If this is
825 * not the case, it can lead to performance problems,
826 * so note that we unexpectedly took the slow path.
828 atomic_inc_64(&zfs_free_range_recv_miss);
831 for (db = list_head(&dn->dn_dbufs); db != NULL; db = db_next) {
832 db_next = list_next(&dn->dn_dbufs, db);
833 ASSERT(db->db_blkid != DMU_BONUS_BLKID);
835 if (db->db_level != 0)
837 if (db->db_blkid < start || db->db_blkid > end)
840 /* found a level 0 buffer in the range */
841 mutex_enter(&db->db_mtx);
842 if (dbuf_undirty(db, tx)) {
843 /* mutex has been dropped and dbuf destroyed */
847 if (db->db_state == DB_UNCACHED ||
848 db->db_state == DB_NOFILL ||
849 db->db_state == DB_EVICTING) {
850 ASSERT(db->db.db_data == NULL);
851 mutex_exit(&db->db_mtx);
854 if (db->db_state == DB_READ || db->db_state == DB_FILL) {
855 /* will be handled in dbuf_read_done or dbuf_rele */
856 db->db_freed_in_flight = TRUE;
857 mutex_exit(&db->db_mtx);
860 if (refcount_count(&db->db_holds) == 0) {
865 /* The dbuf is referenced */
867 if (db->db_last_dirty != NULL) {
868 dbuf_dirty_record_t *dr = db->db_last_dirty;
870 if (dr->dr_txg == txg) {
872 * This buffer is "in-use", re-adjust the file
873 * size to reflect that this buffer may
874 * contain new data when we sync.
876 if (db->db_blkid != DMU_SPILL_BLKID &&
877 db->db_blkid > dn->dn_maxblkid)
878 dn->dn_maxblkid = db->db_blkid;
882 * This dbuf is not dirty in the open context.
883 * Either uncache it (if its not referenced in
884 * the open context) or reset its contents to
887 dbuf_fix_old_data(db, txg);
890 /* clear the contents if its cached */
891 if (db->db_state == DB_CACHED) {
892 ASSERT(db->db.db_data != NULL);
893 arc_release(db->db_buf, db);
894 bzero(db->db.db_data, db->db.db_size);
895 arc_buf_freeze(db->db_buf);
898 mutex_exit(&db->db_mtx);
900 mutex_exit(&dn->dn_dbufs_mtx);
904 dbuf_block_freeable(dmu_buf_impl_t *db)
906 dsl_dataset_t *ds = db->db_objset->os_dsl_dataset;
907 uint64_t birth_txg = 0;
910 * We don't need any locking to protect db_blkptr:
911 * If it's syncing, then db_last_dirty will be set
912 * so we'll ignore db_blkptr.
914 * This logic ensures that only block births for
915 * filled blocks are considered.
917 ASSERT(MUTEX_HELD(&db->db_mtx));
918 if (db->db_last_dirty && (db->db_blkptr == NULL ||
919 !BP_IS_HOLE(db->db_blkptr))) {
920 birth_txg = db->db_last_dirty->dr_txg;
921 } else if (db->db_blkptr != NULL && !BP_IS_HOLE(db->db_blkptr)) {
922 birth_txg = db->db_blkptr->blk_birth;
926 * If this block don't exist or is in a snapshot, it can't be freed.
927 * Don't pass the bp to dsl_dataset_block_freeable() since we
928 * are holding the db_mtx lock and might deadlock if we are
929 * prefetching a dedup-ed block.
932 return (ds == NULL ||
933 dsl_dataset_block_freeable(ds, NULL, birth_txg));
939 dbuf_new_size(dmu_buf_impl_t *db, int size, dmu_tx_t *tx)
941 arc_buf_t *buf, *obuf;
942 int osize = db->db.db_size;
943 arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db);
946 ASSERT(db->db_blkid != DMU_BONUS_BLKID);
951 /* XXX does *this* func really need the lock? */
952 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
955 * This call to dmu_buf_will_dirty() with the dn_struct_rwlock held
956 * is OK, because there can be no other references to the db
957 * when we are changing its size, so no concurrent DB_FILL can
961 * XXX we should be doing a dbuf_read, checking the return
962 * value and returning that up to our callers
964 dmu_buf_will_dirty(&db->db, tx);
966 /* create the data buffer for the new block */
967 buf = arc_buf_alloc(dn->dn_objset->os_spa, size, db, type);
969 /* copy old block data to the new block */
971 bcopy(obuf->b_data, buf->b_data, MIN(osize, size));
972 /* zero the remainder */
974 bzero((uint8_t *)buf->b_data + osize, size - osize);
976 mutex_enter(&db->db_mtx);
977 dbuf_set_data(db, buf);
978 VERIFY(arc_buf_remove_ref(obuf, db));
979 db->db.db_size = size;
981 if (db->db_level == 0) {
982 ASSERT3U(db->db_last_dirty->dr_txg, ==, tx->tx_txg);
983 db->db_last_dirty->dt.dl.dr_data = buf;
985 mutex_exit(&db->db_mtx);
987 dnode_willuse_space(dn, size-osize, tx);
992 dbuf_release_bp(dmu_buf_impl_t *db)
994 objset_t *os = db->db_objset;
996 ASSERT(dsl_pool_sync_context(dmu_objset_pool(os)));
997 ASSERT(arc_released(os->os_phys_buf) ||
998 list_link_active(&os->os_dsl_dataset->ds_synced_link));
999 ASSERT(db->db_parent == NULL || arc_released(db->db_parent->db_buf));
1001 (void) arc_release(db->db_buf, db);
1004 dbuf_dirty_record_t *
1005 dbuf_dirty(dmu_buf_impl_t *db, dmu_tx_t *tx)
1009 dbuf_dirty_record_t **drp, *dr;
1010 int drop_struct_lock = FALSE;
1011 boolean_t do_free_accounting = B_FALSE;
1012 int txgoff = tx->tx_txg & TXG_MASK;
1014 ASSERT(tx->tx_txg != 0);
1015 ASSERT(!refcount_is_zero(&db->db_holds));
1016 DMU_TX_DIRTY_BUF(tx, db);
1021 * Shouldn't dirty a regular buffer in syncing context. Private
1022 * objects may be dirtied in syncing context, but only if they
1023 * were already pre-dirtied in open context.
1025 ASSERT(!dmu_tx_is_syncing(tx) ||
1026 BP_IS_HOLE(dn->dn_objset->os_rootbp) ||
1027 DMU_OBJECT_IS_SPECIAL(dn->dn_object) ||
1028 dn->dn_objset->os_dsl_dataset == NULL);
1030 * We make this assert for private objects as well, but after we
1031 * check if we're already dirty. They are allowed to re-dirty
1032 * in syncing context.
1034 ASSERT(dn->dn_object == DMU_META_DNODE_OBJECT ||
1035 dn->dn_dirtyctx == DN_UNDIRTIED || dn->dn_dirtyctx ==
1036 (dmu_tx_is_syncing(tx) ? DN_DIRTY_SYNC : DN_DIRTY_OPEN));
1038 mutex_enter(&db->db_mtx);
1040 * XXX make this true for indirects too? The problem is that
1041 * transactions created with dmu_tx_create_assigned() from
1042 * syncing context don't bother holding ahead.
1044 ASSERT(db->db_level != 0 ||
1045 db->db_state == DB_CACHED || db->db_state == DB_FILL ||
1046 db->db_state == DB_NOFILL);
1048 mutex_enter(&dn->dn_mtx);
1050 * Don't set dirtyctx to SYNC if we're just modifying this as we
1051 * initialize the objset.
1053 if (dn->dn_dirtyctx == DN_UNDIRTIED &&
1054 !BP_IS_HOLE(dn->dn_objset->os_rootbp)) {
1056 (dmu_tx_is_syncing(tx) ? DN_DIRTY_SYNC : DN_DIRTY_OPEN);
1057 ASSERT(dn->dn_dirtyctx_firstset == NULL);
1058 dn->dn_dirtyctx_firstset = kmem_alloc(1, KM_SLEEP);
1060 mutex_exit(&dn->dn_mtx);
1062 if (db->db_blkid == DMU_SPILL_BLKID)
1063 dn->dn_have_spill = B_TRUE;
1066 * If this buffer is already dirty, we're done.
1068 drp = &db->db_last_dirty;
1069 ASSERT(*drp == NULL || (*drp)->dr_txg <= tx->tx_txg ||
1070 db->db.db_object == DMU_META_DNODE_OBJECT);
1071 while ((dr = *drp) != NULL && dr->dr_txg > tx->tx_txg)
1073 if (dr && dr->dr_txg == tx->tx_txg) {
1076 if (db->db_level == 0 && db->db_blkid != DMU_BONUS_BLKID) {
1078 * If this buffer has already been written out,
1079 * we now need to reset its state.
1081 dbuf_unoverride(dr);
1082 if (db->db.db_object != DMU_META_DNODE_OBJECT &&
1083 db->db_state != DB_NOFILL)
1084 arc_buf_thaw(db->db_buf);
1086 mutex_exit(&db->db_mtx);
1091 * Only valid if not already dirty.
1093 ASSERT(dn->dn_object == 0 ||
1094 dn->dn_dirtyctx == DN_UNDIRTIED || dn->dn_dirtyctx ==
1095 (dmu_tx_is_syncing(tx) ? DN_DIRTY_SYNC : DN_DIRTY_OPEN));
1097 ASSERT3U(dn->dn_nlevels, >, db->db_level);
1098 ASSERT((dn->dn_phys->dn_nlevels == 0 && db->db_level == 0) ||
1099 dn->dn_phys->dn_nlevels > db->db_level ||
1100 dn->dn_next_nlevels[txgoff] > db->db_level ||
1101 dn->dn_next_nlevels[(tx->tx_txg-1) & TXG_MASK] > db->db_level ||
1102 dn->dn_next_nlevels[(tx->tx_txg-2) & TXG_MASK] > db->db_level);
1105 * We should only be dirtying in syncing context if it's the
1106 * mos or we're initializing the os or it's a special object.
1107 * However, we are allowed to dirty in syncing context provided
1108 * we already dirtied it in open context. Hence we must make
1109 * this assertion only if we're not already dirty.
1112 ASSERT(!dmu_tx_is_syncing(tx) || DMU_OBJECT_IS_SPECIAL(dn->dn_object) ||
1113 os->os_dsl_dataset == NULL || BP_IS_HOLE(os->os_rootbp));
1114 ASSERT(db->db.db_size != 0);
1116 dprintf_dbuf(db, "size=%llx\n", (u_longlong_t)db->db.db_size);
1118 if (db->db_blkid != DMU_BONUS_BLKID) {
1120 * Update the accounting.
1121 * Note: we delay "free accounting" until after we drop
1122 * the db_mtx. This keeps us from grabbing other locks
1123 * (and possibly deadlocking) in bp_get_dsize() while
1124 * also holding the db_mtx.
1126 dnode_willuse_space(dn, db->db.db_size, tx);
1127 do_free_accounting = dbuf_block_freeable(db);
1131 * If this buffer is dirty in an old transaction group we need
1132 * to make a copy of it so that the changes we make in this
1133 * transaction group won't leak out when we sync the older txg.
1135 dr = kmem_zalloc(sizeof (dbuf_dirty_record_t), KM_SLEEP);
1136 if (db->db_level == 0) {
1137 void *data_old = db->db_buf;
1139 if (db->db_state != DB_NOFILL) {
1140 if (db->db_blkid == DMU_BONUS_BLKID) {
1141 dbuf_fix_old_data(db, tx->tx_txg);
1142 data_old = db->db.db_data;
1143 } else if (db->db.db_object != DMU_META_DNODE_OBJECT) {
1145 * Release the data buffer from the cache so
1146 * that we can modify it without impacting
1147 * possible other users of this cached data
1148 * block. Note that indirect blocks and
1149 * private objects are not released until the
1150 * syncing state (since they are only modified
1153 arc_release(db->db_buf, db);
1154 dbuf_fix_old_data(db, tx->tx_txg);
1155 data_old = db->db_buf;
1157 ASSERT(data_old != NULL);
1159 dr->dt.dl.dr_data = data_old;
1161 mutex_init(&dr->dt.di.dr_mtx, NULL, MUTEX_DEFAULT, NULL);
1162 list_create(&dr->dt.di.dr_children,
1163 sizeof (dbuf_dirty_record_t),
1164 offsetof(dbuf_dirty_record_t, dr_dirty_node));
1166 if (db->db_blkid != DMU_BONUS_BLKID && os->os_dsl_dataset != NULL)
1167 dr->dr_accounted = db->db.db_size;
1169 dr->dr_txg = tx->tx_txg;
1174 * We could have been freed_in_flight between the dbuf_noread
1175 * and dbuf_dirty. We win, as though the dbuf_noread() had
1176 * happened after the free.
1178 if (db->db_level == 0 && db->db_blkid != DMU_BONUS_BLKID &&
1179 db->db_blkid != DMU_SPILL_BLKID) {
1180 mutex_enter(&dn->dn_mtx);
1181 if (dn->dn_free_ranges[txgoff] != NULL) {
1182 range_tree_clear(dn->dn_free_ranges[txgoff],
1185 mutex_exit(&dn->dn_mtx);
1186 db->db_freed_in_flight = FALSE;
1190 * This buffer is now part of this txg
1192 dbuf_add_ref(db, (void *)(uintptr_t)tx->tx_txg);
1193 db->db_dirtycnt += 1;
1194 ASSERT3U(db->db_dirtycnt, <=, 3);
1196 mutex_exit(&db->db_mtx);
1198 if (db->db_blkid == DMU_BONUS_BLKID ||
1199 db->db_blkid == DMU_SPILL_BLKID) {
1200 mutex_enter(&dn->dn_mtx);
1201 ASSERT(!list_link_active(&dr->dr_dirty_node));
1202 list_insert_tail(&dn->dn_dirty_records[txgoff], dr);
1203 mutex_exit(&dn->dn_mtx);
1204 dnode_setdirty(dn, tx);
1207 } else if (do_free_accounting) {
1208 blkptr_t *bp = db->db_blkptr;
1209 int64_t willfree = (bp && !BP_IS_HOLE(bp)) ?
1210 bp_get_dsize(os->os_spa, bp) : db->db.db_size;
1212 * This is only a guess -- if the dbuf is dirty
1213 * in a previous txg, we don't know how much
1214 * space it will use on disk yet. We should
1215 * really have the struct_rwlock to access
1216 * db_blkptr, but since this is just a guess,
1217 * it's OK if we get an odd answer.
1219 ddt_prefetch(os->os_spa, bp);
1220 dnode_willuse_space(dn, -willfree, tx);
1223 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) {
1224 rw_enter(&dn->dn_struct_rwlock, RW_READER);
1225 drop_struct_lock = TRUE;
1228 if (db->db_level == 0) {
1229 dnode_new_blkid(dn, db->db_blkid, tx, drop_struct_lock);
1230 ASSERT(dn->dn_maxblkid >= db->db_blkid);
1233 if (db->db_level+1 < dn->dn_nlevels) {
1234 dmu_buf_impl_t *parent = db->db_parent;
1235 dbuf_dirty_record_t *di;
1236 int parent_held = FALSE;
1238 if (db->db_parent == NULL || db->db_parent == dn->dn_dbuf) {
1239 int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
1241 parent = dbuf_hold_level(dn, db->db_level+1,
1242 db->db_blkid >> epbs, FTAG);
1243 ASSERT(parent != NULL);
1246 if (drop_struct_lock)
1247 rw_exit(&dn->dn_struct_rwlock);
1248 ASSERT3U(db->db_level+1, ==, parent->db_level);
1249 di = dbuf_dirty(parent, tx);
1251 dbuf_rele(parent, FTAG);
1253 mutex_enter(&db->db_mtx);
1255 * Since we've dropped the mutex, it's possible that
1256 * dbuf_undirty() might have changed this out from under us.
1258 if (db->db_last_dirty == dr ||
1259 dn->dn_object == DMU_META_DNODE_OBJECT) {
1260 mutex_enter(&di->dt.di.dr_mtx);
1261 ASSERT3U(di->dr_txg, ==, tx->tx_txg);
1262 ASSERT(!list_link_active(&dr->dr_dirty_node));
1263 list_insert_tail(&di->dt.di.dr_children, dr);
1264 mutex_exit(&di->dt.di.dr_mtx);
1267 mutex_exit(&db->db_mtx);
1269 ASSERT(db->db_level+1 == dn->dn_nlevels);
1270 ASSERT(db->db_blkid < dn->dn_nblkptr);
1271 ASSERT(db->db_parent == NULL || db->db_parent == dn->dn_dbuf);
1272 mutex_enter(&dn->dn_mtx);
1273 ASSERT(!list_link_active(&dr->dr_dirty_node));
1274 list_insert_tail(&dn->dn_dirty_records[txgoff], dr);
1275 mutex_exit(&dn->dn_mtx);
1276 if (drop_struct_lock)
1277 rw_exit(&dn->dn_struct_rwlock);
1280 dnode_setdirty(dn, tx);
1286 * Undirty a buffer in the transaction group referenced by the given
1287 * transaction. Return whether this evicted the dbuf.
1290 dbuf_undirty(dmu_buf_impl_t *db, dmu_tx_t *tx)
1293 uint64_t txg = tx->tx_txg;
1294 dbuf_dirty_record_t *dr, **drp;
1297 ASSERT(db->db_blkid != DMU_BONUS_BLKID);
1298 ASSERT0(db->db_level);
1299 ASSERT(MUTEX_HELD(&db->db_mtx));
1302 * If this buffer is not dirty, we're done.
1304 for (drp = &db->db_last_dirty; (dr = *drp) != NULL; drp = &dr->dr_next)
1305 if (dr->dr_txg <= txg)
1307 if (dr == NULL || dr->dr_txg < txg)
1309 ASSERT(dr->dr_txg == txg);
1310 ASSERT(dr->dr_dbuf == db);
1315 dprintf_dbuf(db, "size=%llx\n", (u_longlong_t)db->db.db_size);
1317 ASSERT(db->db.db_size != 0);
1320 * Any space we accounted for in dp_dirty_* will be cleaned up by
1321 * dsl_pool_sync(). This is relatively rare so the discrepancy
1322 * is not a big deal.
1328 * Note that there are three places in dbuf_dirty()
1329 * where this dirty record may be put on a list.
1330 * Make sure to do a list_remove corresponding to
1331 * every one of those list_insert calls.
1333 if (dr->dr_parent) {
1334 mutex_enter(&dr->dr_parent->dt.di.dr_mtx);
1335 list_remove(&dr->dr_parent->dt.di.dr_children, dr);
1336 mutex_exit(&dr->dr_parent->dt.di.dr_mtx);
1337 } else if (db->db_blkid == DMU_SPILL_BLKID ||
1338 db->db_level+1 == dn->dn_nlevels) {
1339 ASSERT(db->db_blkptr == NULL || db->db_parent == dn->dn_dbuf);
1340 mutex_enter(&dn->dn_mtx);
1341 list_remove(&dn->dn_dirty_records[txg & TXG_MASK], dr);
1342 mutex_exit(&dn->dn_mtx);
1346 if (db->db_state != DB_NOFILL) {
1347 dbuf_unoverride(dr);
1349 ASSERT(db->db_buf != NULL);
1350 ASSERT(dr->dt.dl.dr_data != NULL);
1351 if (dr->dt.dl.dr_data != db->db_buf)
1352 VERIFY(arc_buf_remove_ref(dr->dt.dl.dr_data, db));
1355 if (db->db_level != 0) {
1356 mutex_destroy(&dr->dt.di.dr_mtx);
1357 list_destroy(&dr->dt.di.dr_children);
1360 kmem_free(dr, sizeof (dbuf_dirty_record_t));
1362 ASSERT(db->db_dirtycnt > 0);
1363 db->db_dirtycnt -= 1;
1365 if (refcount_remove(&db->db_holds, (void *)(uintptr_t)txg) == 0) {
1366 arc_buf_t *buf = db->db_buf;
1368 ASSERT(db->db_state == DB_NOFILL || arc_released(buf));
1369 dbuf_set_data(db, NULL);
1370 VERIFY(arc_buf_remove_ref(buf, db));
1379 dmu_buf_will_dirty(dmu_buf_t *db_fake, dmu_tx_t *tx)
1381 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
1382 int rf = DB_RF_MUST_SUCCEED | DB_RF_NOPREFETCH;
1384 ASSERT(tx->tx_txg != 0);
1385 ASSERT(!refcount_is_zero(&db->db_holds));
1388 if (RW_WRITE_HELD(&DB_DNODE(db)->dn_struct_rwlock))
1389 rf |= DB_RF_HAVESTRUCT;
1391 (void) dbuf_read(db, NULL, rf);
1392 (void) dbuf_dirty(db, tx);
1396 dmu_buf_will_not_fill(dmu_buf_t *db_fake, dmu_tx_t *tx)
1398 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
1400 db->db_state = DB_NOFILL;
1402 dmu_buf_will_fill(db_fake, tx);
1406 dmu_buf_will_fill(dmu_buf_t *db_fake, dmu_tx_t *tx)
1408 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
1410 ASSERT(db->db_blkid != DMU_BONUS_BLKID);
1411 ASSERT(tx->tx_txg != 0);
1412 ASSERT(db->db_level == 0);
1413 ASSERT(!refcount_is_zero(&db->db_holds));
1415 ASSERT(db->db.db_object != DMU_META_DNODE_OBJECT ||
1416 dmu_tx_private_ok(tx));
1419 (void) dbuf_dirty(db, tx);
1422 #pragma weak dmu_buf_fill_done = dbuf_fill_done
1425 dbuf_fill_done(dmu_buf_impl_t *db, dmu_tx_t *tx)
1427 mutex_enter(&db->db_mtx);
1430 if (db->db_state == DB_FILL) {
1431 if (db->db_level == 0 && db->db_freed_in_flight) {
1432 ASSERT(db->db_blkid != DMU_BONUS_BLKID);
1433 /* we were freed while filling */
1434 /* XXX dbuf_undirty? */
1435 bzero(db->db.db_data, db->db.db_size);
1436 db->db_freed_in_flight = FALSE;
1438 db->db_state = DB_CACHED;
1439 cv_broadcast(&db->db_changed);
1441 mutex_exit(&db->db_mtx);
1445 dmu_buf_write_embedded(dmu_buf_t *dbuf, void *data,
1446 bp_embedded_type_t etype, enum zio_compress comp,
1447 int uncompressed_size, int compressed_size, int byteorder,
1450 dmu_buf_impl_t *db = (dmu_buf_impl_t *)dbuf;
1451 struct dirty_leaf *dl;
1452 dmu_object_type_t type;
1455 type = DB_DNODE(db)->dn_type;
1458 ASSERT0(db->db_level);
1459 ASSERT(db->db_blkid != DMU_BONUS_BLKID);
1461 dmu_buf_will_not_fill(dbuf, tx);
1463 ASSERT3U(db->db_last_dirty->dr_txg, ==, tx->tx_txg);
1464 dl = &db->db_last_dirty->dt.dl;
1465 encode_embedded_bp_compressed(&dl->dr_overridden_by,
1466 data, comp, uncompressed_size, compressed_size);
1467 BPE_SET_ETYPE(&dl->dr_overridden_by, etype);
1468 BP_SET_TYPE(&dl->dr_overridden_by, type);
1469 BP_SET_LEVEL(&dl->dr_overridden_by, 0);
1470 BP_SET_BYTEORDER(&dl->dr_overridden_by, byteorder);
1472 dl->dr_override_state = DR_OVERRIDDEN;
1473 dl->dr_overridden_by.blk_birth = db->db_last_dirty->dr_txg;
1477 * Directly assign a provided arc buf to a given dbuf if it's not referenced
1478 * by anybody except our caller. Otherwise copy arcbuf's contents to dbuf.
1481 dbuf_assign_arcbuf(dmu_buf_impl_t *db, arc_buf_t *buf, dmu_tx_t *tx)
1483 ASSERT(!refcount_is_zero(&db->db_holds));
1484 ASSERT(db->db_blkid != DMU_BONUS_BLKID);
1485 ASSERT(db->db_level == 0);
1486 ASSERT(DBUF_GET_BUFC_TYPE(db) == ARC_BUFC_DATA);
1487 ASSERT(buf != NULL);
1488 ASSERT(arc_buf_size(buf) == db->db.db_size);
1489 ASSERT(tx->tx_txg != 0);
1491 arc_return_buf(buf, db);
1492 ASSERT(arc_released(buf));
1494 mutex_enter(&db->db_mtx);
1496 while (db->db_state == DB_READ || db->db_state == DB_FILL)
1497 cv_wait(&db->db_changed, &db->db_mtx);
1499 ASSERT(db->db_state == DB_CACHED || db->db_state == DB_UNCACHED);
1501 if (db->db_state == DB_CACHED &&
1502 refcount_count(&db->db_holds) - 1 > db->db_dirtycnt) {
1503 mutex_exit(&db->db_mtx);
1504 (void) dbuf_dirty(db, tx);
1505 bcopy(buf->b_data, db->db.db_data, db->db.db_size);
1506 VERIFY(arc_buf_remove_ref(buf, db));
1507 xuio_stat_wbuf_copied();
1511 xuio_stat_wbuf_nocopy();
1512 if (db->db_state == DB_CACHED) {
1513 dbuf_dirty_record_t *dr = db->db_last_dirty;
1515 ASSERT(db->db_buf != NULL);
1516 if (dr != NULL && dr->dr_txg == tx->tx_txg) {
1517 ASSERT(dr->dt.dl.dr_data == db->db_buf);
1518 if (!arc_released(db->db_buf)) {
1519 ASSERT(dr->dt.dl.dr_override_state ==
1521 arc_release(db->db_buf, db);
1523 dr->dt.dl.dr_data = buf;
1524 VERIFY(arc_buf_remove_ref(db->db_buf, db));
1525 } else if (dr == NULL || dr->dt.dl.dr_data != db->db_buf) {
1526 arc_release(db->db_buf, db);
1527 VERIFY(arc_buf_remove_ref(db->db_buf, db));
1531 ASSERT(db->db_buf == NULL);
1532 dbuf_set_data(db, buf);
1533 db->db_state = DB_FILL;
1534 mutex_exit(&db->db_mtx);
1535 (void) dbuf_dirty(db, tx);
1536 dmu_buf_fill_done(&db->db, tx);
1540 * "Clear" the contents of this dbuf. This will mark the dbuf
1541 * EVICTING and clear *most* of its references. Unfortunately,
1542 * when we are not holding the dn_dbufs_mtx, we can't clear the
1543 * entry in the dn_dbufs list. We have to wait until dbuf_destroy()
1544 * in this case. For callers from the DMU we will usually see:
1545 * dbuf_clear()->arc_clear_callback()->dbuf_do_evict()->dbuf_destroy()
1546 * For the arc callback, we will usually see:
1547 * dbuf_do_evict()->dbuf_clear();dbuf_destroy()
1548 * Sometimes, though, we will get a mix of these two:
1549 * DMU: dbuf_clear()->arc_clear_callback()
1550 * ARC: dbuf_do_evict()->dbuf_destroy()
1552 * This routine will dissociate the dbuf from the arc, by calling
1553 * arc_clear_callback(), but will not evict the data from the ARC.
1556 dbuf_clear(dmu_buf_impl_t *db)
1559 dmu_buf_impl_t *parent = db->db_parent;
1560 dmu_buf_impl_t *dndb;
1561 boolean_t dbuf_gone = B_FALSE;
1563 ASSERT(MUTEX_HELD(&db->db_mtx));
1564 ASSERT(refcount_is_zero(&db->db_holds));
1566 dbuf_evict_user(db);
1568 if (db->db_state == DB_CACHED) {
1569 ASSERT(db->db.db_data != NULL);
1570 if (db->db_blkid == DMU_BONUS_BLKID) {
1571 zio_buf_free(db->db.db_data, DN_MAX_BONUSLEN);
1572 arc_space_return(DN_MAX_BONUSLEN, ARC_SPACE_OTHER);
1574 db->db.db_data = NULL;
1575 db->db_state = DB_UNCACHED;
1578 ASSERT(db->db_state == DB_UNCACHED || db->db_state == DB_NOFILL);
1579 ASSERT(db->db_data_pending == NULL);
1581 db->db_state = DB_EVICTING;
1582 db->db_blkptr = NULL;
1587 if (db->db_blkid != DMU_BONUS_BLKID && MUTEX_HELD(&dn->dn_dbufs_mtx)) {
1588 list_remove(&dn->dn_dbufs, db);
1589 (void) atomic_dec_32_nv(&dn->dn_dbufs_count);
1593 * Decrementing the dbuf count means that the hold corresponding
1594 * to the removed dbuf is no longer discounted in dnode_move(),
1595 * so the dnode cannot be moved until after we release the hold.
1596 * The membar_producer() ensures visibility of the decremented
1597 * value in dnode_move(), since DB_DNODE_EXIT doesn't actually
1601 db->db_dnode_handle = NULL;
1607 dbuf_gone = arc_clear_callback(db->db_buf);
1610 mutex_exit(&db->db_mtx);
1613 * If this dbuf is referenced from an indirect dbuf,
1614 * decrement the ref count on the indirect dbuf.
1616 if (parent && parent != dndb)
1617 dbuf_rele(parent, db);
1621 dbuf_findbp(dnode_t *dn, int level, uint64_t blkid, int fail_sparse,
1622 dmu_buf_impl_t **parentp, blkptr_t **bpp)
1629 ASSERT(blkid != DMU_BONUS_BLKID);
1631 if (blkid == DMU_SPILL_BLKID) {
1632 mutex_enter(&dn->dn_mtx);
1633 if (dn->dn_have_spill &&
1634 (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR))
1635 *bpp = &dn->dn_phys->dn_spill;
1638 dbuf_add_ref(dn->dn_dbuf, NULL);
1639 *parentp = dn->dn_dbuf;
1640 mutex_exit(&dn->dn_mtx);
1644 if (dn->dn_phys->dn_nlevels == 0)
1647 nlevels = dn->dn_phys->dn_nlevels;
1649 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
1651 ASSERT3U(level * epbs, <, 64);
1652 ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock));
1653 if (level >= nlevels ||
1654 (blkid > (dn->dn_phys->dn_maxblkid >> (level * epbs)))) {
1655 /* the buffer has no parent yet */
1656 return (SET_ERROR(ENOENT));
1657 } else if (level < nlevels-1) {
1658 /* this block is referenced from an indirect block */
1659 int err = dbuf_hold_impl(dn, level+1,
1660 blkid >> epbs, fail_sparse, NULL, parentp);
1663 err = dbuf_read(*parentp, NULL,
1664 (DB_RF_HAVESTRUCT | DB_RF_NOPREFETCH | DB_RF_CANFAIL));
1666 dbuf_rele(*parentp, NULL);
1670 *bpp = ((blkptr_t *)(*parentp)->db.db_data) +
1671 (blkid & ((1ULL << epbs) - 1));
1674 /* the block is referenced from the dnode */
1675 ASSERT3U(level, ==, nlevels-1);
1676 ASSERT(dn->dn_phys->dn_nblkptr == 0 ||
1677 blkid < dn->dn_phys->dn_nblkptr);
1679 dbuf_add_ref(dn->dn_dbuf, NULL);
1680 *parentp = dn->dn_dbuf;
1682 *bpp = &dn->dn_phys->dn_blkptr[blkid];
1687 static dmu_buf_impl_t *
1688 dbuf_create(dnode_t *dn, uint8_t level, uint64_t blkid,
1689 dmu_buf_impl_t *parent, blkptr_t *blkptr)
1691 objset_t *os = dn->dn_objset;
1692 dmu_buf_impl_t *db, *odb;
1694 ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock));
1695 ASSERT(dn->dn_type != DMU_OT_NONE);
1697 db = kmem_cache_alloc(dbuf_cache, KM_SLEEP);
1700 db->db.db_object = dn->dn_object;
1701 db->db_level = level;
1702 db->db_blkid = blkid;
1703 db->db_last_dirty = NULL;
1704 db->db_dirtycnt = 0;
1705 db->db_dnode_handle = dn->dn_handle;
1706 db->db_parent = parent;
1707 db->db_blkptr = blkptr;
1709 db->db_user_ptr = NULL;
1710 db->db_user_data_ptr_ptr = NULL;
1711 db->db_evict_func = NULL;
1712 db->db_immediate_evict = 0;
1713 db->db_freed_in_flight = 0;
1715 if (blkid == DMU_BONUS_BLKID) {
1716 ASSERT3P(parent, ==, dn->dn_dbuf);
1717 db->db.db_size = DN_MAX_BONUSLEN -
1718 (dn->dn_nblkptr-1) * sizeof (blkptr_t);
1719 ASSERT3U(db->db.db_size, >=, dn->dn_bonuslen);
1720 db->db.db_offset = DMU_BONUS_BLKID;
1721 db->db_state = DB_UNCACHED;
1722 /* the bonus dbuf is not placed in the hash table */
1723 arc_space_consume(sizeof (dmu_buf_impl_t), ARC_SPACE_OTHER);
1725 } else if (blkid == DMU_SPILL_BLKID) {
1726 db->db.db_size = (blkptr != NULL) ?
1727 BP_GET_LSIZE(blkptr) : SPA_MINBLOCKSIZE;
1728 db->db.db_offset = 0;
1731 db->db_level ? 1 << dn->dn_indblkshift : dn->dn_datablksz;
1732 db->db.db_size = blocksize;
1733 db->db.db_offset = db->db_blkid * blocksize;
1737 * Hold the dn_dbufs_mtx while we get the new dbuf
1738 * in the hash table *and* added to the dbufs list.
1739 * This prevents a possible deadlock with someone
1740 * trying to look up this dbuf before its added to the
1743 mutex_enter(&dn->dn_dbufs_mtx);
1744 db->db_state = DB_EVICTING;
1745 if ((odb = dbuf_hash_insert(db)) != NULL) {
1746 /* someone else inserted it first */
1747 kmem_cache_free(dbuf_cache, db);
1748 mutex_exit(&dn->dn_dbufs_mtx);
1751 list_insert_head(&dn->dn_dbufs, db);
1752 if (db->db_level == 0 && db->db_blkid >=
1753 dn->dn_unlisted_l0_blkid)
1754 dn->dn_unlisted_l0_blkid = db->db_blkid + 1;
1755 db->db_state = DB_UNCACHED;
1756 mutex_exit(&dn->dn_dbufs_mtx);
1757 arc_space_consume(sizeof (dmu_buf_impl_t), ARC_SPACE_OTHER);
1759 if (parent && parent != dn->dn_dbuf)
1760 dbuf_add_ref(parent, db);
1762 ASSERT(dn->dn_object == DMU_META_DNODE_OBJECT ||
1763 refcount_count(&dn->dn_holds) > 0);
1764 (void) refcount_add(&dn->dn_holds, db);
1765 (void) atomic_inc_32_nv(&dn->dn_dbufs_count);
1767 dprintf_dbuf(db, "db=%p\n", db);
1773 dbuf_do_evict(void *private)
1775 dmu_buf_impl_t *db = private;
1777 if (!MUTEX_HELD(&db->db_mtx))
1778 mutex_enter(&db->db_mtx);
1780 ASSERT(refcount_is_zero(&db->db_holds));
1782 if (db->db_state != DB_EVICTING) {
1783 ASSERT(db->db_state == DB_CACHED);
1788 mutex_exit(&db->db_mtx);
1795 dbuf_destroy(dmu_buf_impl_t *db)
1797 ASSERT(refcount_is_zero(&db->db_holds));
1799 if (db->db_blkid != DMU_BONUS_BLKID) {
1801 * If this dbuf is still on the dn_dbufs list,
1802 * remove it from that list.
1804 if (db->db_dnode_handle != NULL) {
1809 mutex_enter(&dn->dn_dbufs_mtx);
1810 list_remove(&dn->dn_dbufs, db);
1811 (void) atomic_dec_32_nv(&dn->dn_dbufs_count);
1812 mutex_exit(&dn->dn_dbufs_mtx);
1815 * Decrementing the dbuf count means that the hold
1816 * corresponding to the removed dbuf is no longer
1817 * discounted in dnode_move(), so the dnode cannot be
1818 * moved until after we release the hold.
1821 db->db_dnode_handle = NULL;
1823 dbuf_hash_remove(db);
1825 db->db_parent = NULL;
1828 ASSERT(!list_link_active(&db->db_link));
1829 ASSERT(db->db.db_data == NULL);
1830 ASSERT(db->db_hash_next == NULL);
1831 ASSERT(db->db_blkptr == NULL);
1832 ASSERT(db->db_data_pending == NULL);
1834 kmem_cache_free(dbuf_cache, db);
1835 arc_space_return(sizeof (dmu_buf_impl_t), ARC_SPACE_OTHER);
1839 dbuf_prefetch(dnode_t *dn, uint64_t blkid, zio_priority_t prio)
1841 dmu_buf_impl_t *db = NULL;
1842 blkptr_t *bp = NULL;
1844 ASSERT(blkid != DMU_BONUS_BLKID);
1845 ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock));
1847 if (dnode_block_freed(dn, blkid))
1850 /* dbuf_find() returns with db_mtx held */
1851 if (db = dbuf_find(dn, 0, blkid)) {
1853 * This dbuf is already in the cache. We assume that
1854 * it is already CACHED, or else about to be either
1857 mutex_exit(&db->db_mtx);
1861 if (dbuf_findbp(dn, 0, blkid, TRUE, &db, &bp) == 0) {
1862 if (bp && !BP_IS_HOLE(bp) && !BP_IS_EMBEDDED(bp)) {
1863 dsl_dataset_t *ds = dn->dn_objset->os_dsl_dataset;
1864 uint32_t aflags = ARC_NOWAIT | ARC_PREFETCH;
1865 zbookmark_phys_t zb;
1867 SET_BOOKMARK(&zb, ds ? ds->ds_object : DMU_META_OBJSET,
1868 dn->dn_object, 0, blkid);
1870 (void) arc_read(NULL, dn->dn_objset->os_spa,
1871 bp, NULL, NULL, prio,
1872 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE,
1876 dbuf_rele(db, NULL);
1881 * Returns with db_holds incremented, and db_mtx not held.
1882 * Note: dn_struct_rwlock must be held.
1885 dbuf_hold_impl(dnode_t *dn, uint8_t level, uint64_t blkid, int fail_sparse,
1886 void *tag, dmu_buf_impl_t **dbp)
1888 dmu_buf_impl_t *db, *parent = NULL;
1890 ASSERT(blkid != DMU_BONUS_BLKID);
1891 ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock));
1892 ASSERT3U(dn->dn_nlevels, >, level);
1896 /* dbuf_find() returns with db_mtx held */
1897 db = dbuf_find(dn, level, blkid);
1900 blkptr_t *bp = NULL;
1903 ASSERT3P(parent, ==, NULL);
1904 err = dbuf_findbp(dn, level, blkid, fail_sparse, &parent, &bp);
1906 if (err == 0 && bp && BP_IS_HOLE(bp))
1907 err = SET_ERROR(ENOENT);
1910 dbuf_rele(parent, NULL);
1914 if (err && err != ENOENT)
1916 db = dbuf_create(dn, level, blkid, parent, bp);
1919 if (db->db_buf && refcount_is_zero(&db->db_holds)) {
1920 arc_buf_add_ref(db->db_buf, db);
1921 if (db->db_buf->b_data == NULL) {
1924 dbuf_rele(parent, NULL);
1929 ASSERT3P(db->db.db_data, ==, db->db_buf->b_data);
1932 ASSERT(db->db_buf == NULL || arc_referenced(db->db_buf));
1935 * If this buffer is currently syncing out, and we are are
1936 * still referencing it from db_data, we need to make a copy
1937 * of it in case we decide we want to dirty it again in this txg.
1939 if (db->db_level == 0 && db->db_blkid != DMU_BONUS_BLKID &&
1940 dn->dn_object != DMU_META_DNODE_OBJECT &&
1941 db->db_state == DB_CACHED && db->db_data_pending) {
1942 dbuf_dirty_record_t *dr = db->db_data_pending;
1944 if (dr->dt.dl.dr_data == db->db_buf) {
1945 arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db);
1948 arc_buf_alloc(dn->dn_objset->os_spa,
1949 db->db.db_size, db, type));
1950 bcopy(dr->dt.dl.dr_data->b_data, db->db.db_data,
1955 (void) refcount_add(&db->db_holds, tag);
1956 dbuf_update_data(db);
1958 mutex_exit(&db->db_mtx);
1960 /* NOTE: we can't rele the parent until after we drop the db_mtx */
1962 dbuf_rele(parent, NULL);
1964 ASSERT3P(DB_DNODE(db), ==, dn);
1965 ASSERT3U(db->db_blkid, ==, blkid);
1966 ASSERT3U(db->db_level, ==, level);
1973 dbuf_hold(dnode_t *dn, uint64_t blkid, void *tag)
1976 int err = dbuf_hold_impl(dn, 0, blkid, FALSE, tag, &db);
1977 return (err ? NULL : db);
1981 dbuf_hold_level(dnode_t *dn, int level, uint64_t blkid, void *tag)
1984 int err = dbuf_hold_impl(dn, level, blkid, FALSE, tag, &db);
1985 return (err ? NULL : db);
1989 dbuf_create_bonus(dnode_t *dn)
1991 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
1993 ASSERT(dn->dn_bonus == NULL);
1994 dn->dn_bonus = dbuf_create(dn, 0, DMU_BONUS_BLKID, dn->dn_dbuf, NULL);
1998 dbuf_spill_set_blksz(dmu_buf_t *db_fake, uint64_t blksz, dmu_tx_t *tx)
2000 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
2003 if (db->db_blkid != DMU_SPILL_BLKID)
2004 return (SET_ERROR(ENOTSUP));
2006 blksz = SPA_MINBLOCKSIZE;
2007 if (blksz > SPA_MAXBLOCKSIZE)
2008 blksz = SPA_MAXBLOCKSIZE;
2010 blksz = P2ROUNDUP(blksz, SPA_MINBLOCKSIZE);
2014 rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
2015 dbuf_new_size(db, blksz, tx);
2016 rw_exit(&dn->dn_struct_rwlock);
2023 dbuf_rm_spill(dnode_t *dn, dmu_tx_t *tx)
2025 dbuf_free_range(dn, DMU_SPILL_BLKID, DMU_SPILL_BLKID, tx);
2028 #pragma weak dmu_buf_add_ref = dbuf_add_ref
2030 dbuf_add_ref(dmu_buf_impl_t *db, void *tag)
2032 int64_t holds = refcount_add(&db->db_holds, tag);
2037 * If you call dbuf_rele() you had better not be referencing the dnode handle
2038 * unless you have some other direct or indirect hold on the dnode. (An indirect
2039 * hold is a hold on one of the dnode's dbufs, including the bonus buffer.)
2040 * Without that, the dbuf_rele() could lead to a dnode_rele() followed by the
2041 * dnode's parent dbuf evicting its dnode handles.
2044 dbuf_rele(dmu_buf_impl_t *db, void *tag)
2046 mutex_enter(&db->db_mtx);
2047 dbuf_rele_and_unlock(db, tag);
2051 dmu_buf_rele(dmu_buf_t *db, void *tag)
2053 dbuf_rele((dmu_buf_impl_t *)db, tag);
2057 * dbuf_rele() for an already-locked dbuf. This is necessary to allow
2058 * db_dirtycnt and db_holds to be updated atomically.
2061 dbuf_rele_and_unlock(dmu_buf_impl_t *db, void *tag)
2065 ASSERT(MUTEX_HELD(&db->db_mtx));
2069 * Remove the reference to the dbuf before removing its hold on the
2070 * dnode so we can guarantee in dnode_move() that a referenced bonus
2071 * buffer has a corresponding dnode hold.
2073 holds = refcount_remove(&db->db_holds, tag);
2077 * We can't freeze indirects if there is a possibility that they
2078 * may be modified in the current syncing context.
2080 if (db->db_buf && holds == (db->db_level == 0 ? db->db_dirtycnt : 0))
2081 arc_buf_freeze(db->db_buf);
2083 if (holds == db->db_dirtycnt &&
2084 db->db_level == 0 && db->db_immediate_evict)
2085 dbuf_evict_user(db);
2088 if (db->db_blkid == DMU_BONUS_BLKID) {
2089 mutex_exit(&db->db_mtx);
2092 * If the dnode moves here, we cannot cross this barrier
2093 * until the move completes.
2096 (void) atomic_dec_32_nv(&DB_DNODE(db)->dn_dbufs_count);
2099 * The bonus buffer's dnode hold is no longer discounted
2100 * in dnode_move(). The dnode cannot move until after
2103 dnode_rele(DB_DNODE(db), db);
2104 } else if (db->db_buf == NULL) {
2106 * This is a special case: we never associated this
2107 * dbuf with any data allocated from the ARC.
2109 ASSERT(db->db_state == DB_UNCACHED ||
2110 db->db_state == DB_NOFILL);
2112 } else if (arc_released(db->db_buf)) {
2113 arc_buf_t *buf = db->db_buf;
2115 * This dbuf has anonymous data associated with it.
2117 dbuf_set_data(db, NULL);
2118 VERIFY(arc_buf_remove_ref(buf, db));
2121 VERIFY(!arc_buf_remove_ref(db->db_buf, db));
2124 * A dbuf will be eligible for eviction if either the
2125 * 'primarycache' property is set or a duplicate
2126 * copy of this buffer is already cached in the arc.
2128 * In the case of the 'primarycache' a buffer
2129 * is considered for eviction if it matches the
2130 * criteria set in the property.
2132 * To decide if our buffer is considered a
2133 * duplicate, we must call into the arc to determine
2134 * if multiple buffers are referencing the same
2135 * block on-disk. If so, then we simply evict
2138 if (!DBUF_IS_CACHEABLE(db)) {
2139 if (db->db_blkptr != NULL &&
2140 !BP_IS_HOLE(db->db_blkptr) &&
2141 !BP_IS_EMBEDDED(db->db_blkptr)) {
2143 dmu_objset_spa(db->db_objset);
2144 blkptr_t bp = *db->db_blkptr;
2146 arc_freed(spa, &bp);
2150 } else if (arc_buf_eviction_needed(db->db_buf)) {
2153 mutex_exit(&db->db_mtx);
2157 mutex_exit(&db->db_mtx);
2161 #pragma weak dmu_buf_refcount = dbuf_refcount
2163 dbuf_refcount(dmu_buf_impl_t *db)
2165 return (refcount_count(&db->db_holds));
2169 dmu_buf_set_user(dmu_buf_t *db_fake, void *user_ptr, void *user_data_ptr_ptr,
2170 dmu_buf_evict_func_t *evict_func)
2172 return (dmu_buf_update_user(db_fake, NULL, user_ptr,
2173 user_data_ptr_ptr, evict_func));
2177 dmu_buf_set_user_ie(dmu_buf_t *db_fake, void *user_ptr, void *user_data_ptr_ptr,
2178 dmu_buf_evict_func_t *evict_func)
2180 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
2182 db->db_immediate_evict = TRUE;
2183 return (dmu_buf_update_user(db_fake, NULL, user_ptr,
2184 user_data_ptr_ptr, evict_func));
2188 dmu_buf_update_user(dmu_buf_t *db_fake, void *old_user_ptr, void *user_ptr,
2189 void *user_data_ptr_ptr, dmu_buf_evict_func_t *evict_func)
2191 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
2192 ASSERT(db->db_level == 0);
2194 ASSERT((user_ptr == NULL) == (evict_func == NULL));
2196 mutex_enter(&db->db_mtx);
2198 if (db->db_user_ptr == old_user_ptr) {
2199 db->db_user_ptr = user_ptr;
2200 db->db_user_data_ptr_ptr = user_data_ptr_ptr;
2201 db->db_evict_func = evict_func;
2203 dbuf_update_data(db);
2205 old_user_ptr = db->db_user_ptr;
2208 mutex_exit(&db->db_mtx);
2209 return (old_user_ptr);
2213 dmu_buf_get_user(dmu_buf_t *db_fake)
2215 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
2216 ASSERT(!refcount_is_zero(&db->db_holds));
2218 return (db->db_user_ptr);
2222 dmu_buf_freeable(dmu_buf_t *dbuf)
2224 boolean_t res = B_FALSE;
2225 dmu_buf_impl_t *db = (dmu_buf_impl_t *)dbuf;
2228 res = dsl_dataset_block_freeable(db->db_objset->os_dsl_dataset,
2229 db->db_blkptr, db->db_blkptr->blk_birth);
2235 dmu_buf_get_blkptr(dmu_buf_t *db)
2237 dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db;
2238 return (dbi->db_blkptr);
2242 dbuf_check_blkptr(dnode_t *dn, dmu_buf_impl_t *db)
2244 /* ASSERT(dmu_tx_is_syncing(tx) */
2245 ASSERT(MUTEX_HELD(&db->db_mtx));
2247 if (db->db_blkptr != NULL)
2250 if (db->db_blkid == DMU_SPILL_BLKID) {
2251 db->db_blkptr = &dn->dn_phys->dn_spill;
2252 BP_ZERO(db->db_blkptr);
2255 if (db->db_level == dn->dn_phys->dn_nlevels-1) {
2257 * This buffer was allocated at a time when there was
2258 * no available blkptrs from the dnode, or it was
2259 * inappropriate to hook it in (i.e., nlevels mis-match).
2261 ASSERT(db->db_blkid < dn->dn_phys->dn_nblkptr);
2262 ASSERT(db->db_parent == NULL);
2263 db->db_parent = dn->dn_dbuf;
2264 db->db_blkptr = &dn->dn_phys->dn_blkptr[db->db_blkid];
2267 dmu_buf_impl_t *parent = db->db_parent;
2268 int epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
2270 ASSERT(dn->dn_phys->dn_nlevels > 1);
2271 if (parent == NULL) {
2272 mutex_exit(&db->db_mtx);
2273 rw_enter(&dn->dn_struct_rwlock, RW_READER);
2274 (void) dbuf_hold_impl(dn, db->db_level+1,
2275 db->db_blkid >> epbs, FALSE, db, &parent);
2276 rw_exit(&dn->dn_struct_rwlock);
2277 mutex_enter(&db->db_mtx);
2278 db->db_parent = parent;
2280 db->db_blkptr = (blkptr_t *)parent->db.db_data +
2281 (db->db_blkid & ((1ULL << epbs) - 1));
2287 dbuf_sync_indirect(dbuf_dirty_record_t *dr, dmu_tx_t *tx)
2289 dmu_buf_impl_t *db = dr->dr_dbuf;
2293 ASSERT(dmu_tx_is_syncing(tx));
2295 dprintf_dbuf_bp(db, db->db_blkptr, "blkptr=%p", db->db_blkptr);
2297 mutex_enter(&db->db_mtx);
2299 ASSERT(db->db_level > 0);
2302 /* Read the block if it hasn't been read yet. */
2303 if (db->db_buf == NULL) {
2304 mutex_exit(&db->db_mtx);
2305 (void) dbuf_read(db, NULL, DB_RF_MUST_SUCCEED);
2306 mutex_enter(&db->db_mtx);
2308 ASSERT3U(db->db_state, ==, DB_CACHED);
2309 ASSERT(db->db_buf != NULL);
2313 /* Indirect block size must match what the dnode thinks it is. */
2314 ASSERT3U(db->db.db_size, ==, 1<<dn->dn_phys->dn_indblkshift);
2315 dbuf_check_blkptr(dn, db);
2318 /* Provide the pending dirty record to child dbufs */
2319 db->db_data_pending = dr;
2321 mutex_exit(&db->db_mtx);
2322 dbuf_write(dr, db->db_buf, tx);
2325 mutex_enter(&dr->dt.di.dr_mtx);
2326 dbuf_sync_list(&dr->dt.di.dr_children, tx);
2327 ASSERT(list_head(&dr->dt.di.dr_children) == NULL);
2328 mutex_exit(&dr->dt.di.dr_mtx);
2333 dbuf_sync_leaf(dbuf_dirty_record_t *dr, dmu_tx_t *tx)
2335 arc_buf_t **datap = &dr->dt.dl.dr_data;
2336 dmu_buf_impl_t *db = dr->dr_dbuf;
2339 uint64_t txg = tx->tx_txg;
2341 ASSERT(dmu_tx_is_syncing(tx));
2343 dprintf_dbuf_bp(db, db->db_blkptr, "blkptr=%p", db->db_blkptr);
2345 mutex_enter(&db->db_mtx);
2347 * To be synced, we must be dirtied. But we
2348 * might have been freed after the dirty.
2350 if (db->db_state == DB_UNCACHED) {
2351 /* This buffer has been freed since it was dirtied */
2352 ASSERT(db->db.db_data == NULL);
2353 } else if (db->db_state == DB_FILL) {
2354 /* This buffer was freed and is now being re-filled */
2355 ASSERT(db->db.db_data != dr->dt.dl.dr_data);
2357 ASSERT(db->db_state == DB_CACHED || db->db_state == DB_NOFILL);
2364 if (db->db_blkid == DMU_SPILL_BLKID) {
2365 mutex_enter(&dn->dn_mtx);
2366 dn->dn_phys->dn_flags |= DNODE_FLAG_SPILL_BLKPTR;
2367 mutex_exit(&dn->dn_mtx);
2371 * If this is a bonus buffer, simply copy the bonus data into the
2372 * dnode. It will be written out when the dnode is synced (and it
2373 * will be synced, since it must have been dirty for dbuf_sync to
2376 if (db->db_blkid == DMU_BONUS_BLKID) {
2377 dbuf_dirty_record_t **drp;
2379 ASSERT(*datap != NULL);
2380 ASSERT0(db->db_level);
2381 ASSERT3U(dn->dn_phys->dn_bonuslen, <=, DN_MAX_BONUSLEN);
2382 bcopy(*datap, DN_BONUS(dn->dn_phys), dn->dn_phys->dn_bonuslen);
2385 if (*datap != db->db.db_data) {
2386 zio_buf_free(*datap, DN_MAX_BONUSLEN);
2387 arc_space_return(DN_MAX_BONUSLEN, ARC_SPACE_OTHER);
2389 db->db_data_pending = NULL;
2390 drp = &db->db_last_dirty;
2392 drp = &(*drp)->dr_next;
2393 ASSERT(dr->dr_next == NULL);
2394 ASSERT(dr->dr_dbuf == db);
2396 if (dr->dr_dbuf->db_level != 0) {
2397 list_destroy(&dr->dt.di.dr_children);
2398 mutex_destroy(&dr->dt.di.dr_mtx);
2400 kmem_free(dr, sizeof (dbuf_dirty_record_t));
2401 ASSERT(db->db_dirtycnt > 0);
2402 db->db_dirtycnt -= 1;
2403 dbuf_rele_and_unlock(db, (void *)(uintptr_t)txg);
2410 * This function may have dropped the db_mtx lock allowing a dmu_sync
2411 * operation to sneak in. As a result, we need to ensure that we
2412 * don't check the dr_override_state until we have returned from
2413 * dbuf_check_blkptr.
2415 dbuf_check_blkptr(dn, db);
2418 * If this buffer is in the middle of an immediate write,
2419 * wait for the synchronous IO to complete.
2421 while (dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC) {
2422 ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT);
2423 cv_wait(&db->db_changed, &db->db_mtx);
2424 ASSERT(dr->dt.dl.dr_override_state != DR_NOT_OVERRIDDEN);
2427 if (db->db_state != DB_NOFILL &&
2428 dn->dn_object != DMU_META_DNODE_OBJECT &&
2429 refcount_count(&db->db_holds) > 1 &&
2430 dr->dt.dl.dr_override_state != DR_OVERRIDDEN &&
2431 *datap == db->db_buf) {
2433 * If this buffer is currently "in use" (i.e., there
2434 * are active holds and db_data still references it),
2435 * then make a copy before we start the write so that
2436 * any modifications from the open txg will not leak
2439 * NOTE: this copy does not need to be made for
2440 * objects only modified in the syncing context (e.g.
2441 * DNONE_DNODE blocks).
2443 int blksz = arc_buf_size(*datap);
2444 arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db);
2445 *datap = arc_buf_alloc(os->os_spa, blksz, db, type);
2446 bcopy(db->db.db_data, (*datap)->b_data, blksz);
2448 db->db_data_pending = dr;
2450 mutex_exit(&db->db_mtx);
2452 dbuf_write(dr, *datap, tx);
2454 ASSERT(!list_link_active(&dr->dr_dirty_node));
2455 if (dn->dn_object == DMU_META_DNODE_OBJECT) {
2456 list_insert_tail(&dn->dn_dirty_records[txg&TXG_MASK], dr);
2460 * Although zio_nowait() does not "wait for an IO", it does
2461 * initiate the IO. If this is an empty write it seems plausible
2462 * that the IO could actually be completed before the nowait
2463 * returns. We need to DB_DNODE_EXIT() first in case
2464 * zio_nowait() invalidates the dbuf.
2467 zio_nowait(dr->dr_zio);
2472 dbuf_sync_list(list_t *list, dmu_tx_t *tx)
2474 dbuf_dirty_record_t *dr;
2476 while (dr = list_head(list)) {
2477 if (dr->dr_zio != NULL) {
2479 * If we find an already initialized zio then we
2480 * are processing the meta-dnode, and we have finished.
2481 * The dbufs for all dnodes are put back on the list
2482 * during processing, so that we can zio_wait()
2483 * these IOs after initiating all child IOs.
2485 ASSERT3U(dr->dr_dbuf->db.db_object, ==,
2486 DMU_META_DNODE_OBJECT);
2489 list_remove(list, dr);
2490 if (dr->dr_dbuf->db_level > 0)
2491 dbuf_sync_indirect(dr, tx);
2493 dbuf_sync_leaf(dr, tx);
2499 dbuf_write_ready(zio_t *zio, arc_buf_t *buf, void *vdb)
2501 dmu_buf_impl_t *db = vdb;
2503 blkptr_t *bp = zio->io_bp;
2504 blkptr_t *bp_orig = &zio->io_bp_orig;
2505 spa_t *spa = zio->io_spa;
2510 ASSERT3P(db->db_blkptr, ==, bp);
2514 delta = bp_get_dsize_sync(spa, bp) - bp_get_dsize_sync(spa, bp_orig);
2515 dnode_diduse_space(dn, delta - zio->io_prev_space_delta);
2516 zio->io_prev_space_delta = delta;
2518 if (bp->blk_birth != 0) {
2519 ASSERT((db->db_blkid != DMU_SPILL_BLKID &&
2520 BP_GET_TYPE(bp) == dn->dn_type) ||
2521 (db->db_blkid == DMU_SPILL_BLKID &&
2522 BP_GET_TYPE(bp) == dn->dn_bonustype) ||
2523 BP_IS_EMBEDDED(bp));
2524 ASSERT(BP_GET_LEVEL(bp) == db->db_level);
2527 mutex_enter(&db->db_mtx);
2530 if (db->db_blkid == DMU_SPILL_BLKID) {
2531 ASSERT(dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR);
2532 ASSERT(!(BP_IS_HOLE(db->db_blkptr)) &&
2533 db->db_blkptr == &dn->dn_phys->dn_spill);
2537 if (db->db_level == 0) {
2538 mutex_enter(&dn->dn_mtx);
2539 if (db->db_blkid > dn->dn_phys->dn_maxblkid &&
2540 db->db_blkid != DMU_SPILL_BLKID)
2541 dn->dn_phys->dn_maxblkid = db->db_blkid;
2542 mutex_exit(&dn->dn_mtx);
2544 if (dn->dn_type == DMU_OT_DNODE) {
2545 dnode_phys_t *dnp = db->db.db_data;
2546 for (i = db->db.db_size >> DNODE_SHIFT; i > 0;
2548 if (dnp->dn_type != DMU_OT_NONE)
2552 if (BP_IS_HOLE(bp)) {
2559 blkptr_t *ibp = db->db.db_data;
2560 ASSERT3U(db->db.db_size, ==, 1<<dn->dn_phys->dn_indblkshift);
2561 for (i = db->db.db_size >> SPA_BLKPTRSHIFT; i > 0; i--, ibp++) {
2562 if (BP_IS_HOLE(ibp))
2564 fill += BP_GET_FILL(ibp);
2569 if (!BP_IS_EMBEDDED(bp))
2570 bp->blk_fill = fill;
2572 mutex_exit(&db->db_mtx);
2576 * The SPA will call this callback several times for each zio - once
2577 * for every physical child i/o (zio->io_phys_children times). This
2578 * allows the DMU to monitor the progress of each logical i/o. For example,
2579 * there may be 2 copies of an indirect block, or many fragments of a RAID-Z
2580 * block. There may be a long delay before all copies/fragments are completed,
2581 * so this callback allows us to retire dirty space gradually, as the physical
2586 dbuf_write_physdone(zio_t *zio, arc_buf_t *buf, void *arg)
2588 dmu_buf_impl_t *db = arg;
2589 objset_t *os = db->db_objset;
2590 dsl_pool_t *dp = dmu_objset_pool(os);
2591 dbuf_dirty_record_t *dr;
2594 dr = db->db_data_pending;
2595 ASSERT3U(dr->dr_txg, ==, zio->io_txg);
2598 * The callback will be called io_phys_children times. Retire one
2599 * portion of our dirty space each time we are called. Any rounding
2600 * error will be cleaned up by dsl_pool_sync()'s call to
2601 * dsl_pool_undirty_space().
2603 delta = dr->dr_accounted / zio->io_phys_children;
2604 dsl_pool_undirty_space(dp, delta, zio->io_txg);
2609 dbuf_write_done(zio_t *zio, arc_buf_t *buf, void *vdb)
2611 dmu_buf_impl_t *db = vdb;
2612 blkptr_t *bp_orig = &zio->io_bp_orig;
2613 blkptr_t *bp = db->db_blkptr;
2614 objset_t *os = db->db_objset;
2615 dmu_tx_t *tx = os->os_synctx;
2616 dbuf_dirty_record_t **drp, *dr;
2618 ASSERT0(zio->io_error);
2619 ASSERT(db->db_blkptr == bp);
2622 * For nopwrites and rewrites we ensure that the bp matches our
2623 * original and bypass all the accounting.
2625 if (zio->io_flags & (ZIO_FLAG_IO_REWRITE | ZIO_FLAG_NOPWRITE)) {
2626 ASSERT(BP_EQUAL(bp, bp_orig));
2628 dsl_dataset_t *ds = os->os_dsl_dataset;
2629 (void) dsl_dataset_block_kill(ds, bp_orig, tx, B_TRUE);
2630 dsl_dataset_block_born(ds, bp, tx);
2633 mutex_enter(&db->db_mtx);
2637 drp = &db->db_last_dirty;
2638 while ((dr = *drp) != db->db_data_pending)
2640 ASSERT(!list_link_active(&dr->dr_dirty_node));
2641 ASSERT(dr->dr_dbuf == db);
2642 ASSERT(dr->dr_next == NULL);
2646 if (db->db_blkid == DMU_SPILL_BLKID) {
2651 ASSERT(dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR);
2652 ASSERT(!(BP_IS_HOLE(db->db_blkptr)) &&
2653 db->db_blkptr == &dn->dn_phys->dn_spill);
2658 if (db->db_level == 0) {
2659 ASSERT(db->db_blkid != DMU_BONUS_BLKID);
2660 ASSERT(dr->dt.dl.dr_override_state == DR_NOT_OVERRIDDEN);
2661 if (db->db_state != DB_NOFILL) {
2662 if (dr->dt.dl.dr_data != db->db_buf)
2663 VERIFY(arc_buf_remove_ref(dr->dt.dl.dr_data,
2665 else if (!arc_released(db->db_buf))
2666 arc_set_callback(db->db_buf, dbuf_do_evict, db);
2673 ASSERT(list_head(&dr->dt.di.dr_children) == NULL);
2674 ASSERT3U(db->db.db_size, ==, 1 << dn->dn_phys->dn_indblkshift);
2675 if (!BP_IS_HOLE(db->db_blkptr)) {
2677 dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
2678 ASSERT3U(db->db_blkid, <=,
2679 dn->dn_phys->dn_maxblkid >> (db->db_level * epbs));
2680 ASSERT3U(BP_GET_LSIZE(db->db_blkptr), ==,
2682 if (!arc_released(db->db_buf))
2683 arc_set_callback(db->db_buf, dbuf_do_evict, db);
2686 mutex_destroy(&dr->dt.di.dr_mtx);
2687 list_destroy(&dr->dt.di.dr_children);
2689 kmem_free(dr, sizeof (dbuf_dirty_record_t));
2691 cv_broadcast(&db->db_changed);
2692 ASSERT(db->db_dirtycnt > 0);
2693 db->db_dirtycnt -= 1;
2694 db->db_data_pending = NULL;
2695 dbuf_rele_and_unlock(db, (void *)(uintptr_t)tx->tx_txg);
2699 dbuf_write_nofill_ready(zio_t *zio)
2701 dbuf_write_ready(zio, NULL, zio->io_private);
2705 dbuf_write_nofill_done(zio_t *zio)
2707 dbuf_write_done(zio, NULL, zio->io_private);
2711 dbuf_write_override_ready(zio_t *zio)
2713 dbuf_dirty_record_t *dr = zio->io_private;
2714 dmu_buf_impl_t *db = dr->dr_dbuf;
2716 dbuf_write_ready(zio, NULL, db);
2720 dbuf_write_override_done(zio_t *zio)
2722 dbuf_dirty_record_t *dr = zio->io_private;
2723 dmu_buf_impl_t *db = dr->dr_dbuf;
2724 blkptr_t *obp = &dr->dt.dl.dr_overridden_by;
2726 mutex_enter(&db->db_mtx);
2727 if (!BP_EQUAL(zio->io_bp, obp)) {
2728 if (!BP_IS_HOLE(obp))
2729 dsl_free(spa_get_dsl(zio->io_spa), zio->io_txg, obp);
2730 arc_release(dr->dt.dl.dr_data, db);
2732 mutex_exit(&db->db_mtx);
2734 dbuf_write_done(zio, NULL, db);
2737 /* Issue I/O to commit a dirty buffer to disk. */
2739 dbuf_write(dbuf_dirty_record_t *dr, arc_buf_t *data, dmu_tx_t *tx)
2741 dmu_buf_impl_t *db = dr->dr_dbuf;
2744 dmu_buf_impl_t *parent = db->db_parent;
2745 uint64_t txg = tx->tx_txg;
2746 zbookmark_phys_t zb;
2755 if (db->db_state != DB_NOFILL) {
2756 if (db->db_level > 0 || dn->dn_type == DMU_OT_DNODE) {
2758 * Private object buffers are released here rather
2759 * than in dbuf_dirty() since they are only modified
2760 * in the syncing context and we don't want the
2761 * overhead of making multiple copies of the data.
2763 if (BP_IS_HOLE(db->db_blkptr)) {
2766 dbuf_release_bp(db);
2771 if (parent != dn->dn_dbuf) {
2772 /* Our parent is an indirect block. */
2773 /* We have a dirty parent that has been scheduled for write. */
2774 ASSERT(parent && parent->db_data_pending);
2775 /* Our parent's buffer is one level closer to the dnode. */
2776 ASSERT(db->db_level == parent->db_level-1);
2778 * We're about to modify our parent's db_data by modifying
2779 * our block pointer, so the parent must be released.
2781 ASSERT(arc_released(parent->db_buf));
2782 zio = parent->db_data_pending->dr_zio;
2784 /* Our parent is the dnode itself. */
2785 ASSERT((db->db_level == dn->dn_phys->dn_nlevels-1 &&
2786 db->db_blkid != DMU_SPILL_BLKID) ||
2787 (db->db_blkid == DMU_SPILL_BLKID && db->db_level == 0));
2788 if (db->db_blkid != DMU_SPILL_BLKID)
2789 ASSERT3P(db->db_blkptr, ==,
2790 &dn->dn_phys->dn_blkptr[db->db_blkid]);
2794 ASSERT(db->db_level == 0 || data == db->db_buf);
2795 ASSERT3U(db->db_blkptr->blk_birth, <=, txg);
2798 SET_BOOKMARK(&zb, os->os_dsl_dataset ?
2799 os->os_dsl_dataset->ds_object : DMU_META_OBJSET,
2800 db->db.db_object, db->db_level, db->db_blkid);
2802 if (db->db_blkid == DMU_SPILL_BLKID)
2804 wp_flag |= (db->db_state == DB_NOFILL) ? WP_NOFILL : 0;
2806 dmu_write_policy(os, dn, db->db_level, wp_flag, &zp);
2809 if (db->db_level == 0 &&
2810 dr->dt.dl.dr_override_state == DR_OVERRIDDEN) {
2812 * The BP for this block has been provided by open context
2813 * (by dmu_sync() or dmu_buf_write_embedded()).
2815 void *contents = (data != NULL) ? data->b_data : NULL;
2817 dr->dr_zio = zio_write(zio, os->os_spa, txg,
2818 db->db_blkptr, contents, db->db.db_size, &zp,
2819 dbuf_write_override_ready, NULL, dbuf_write_override_done,
2820 dr, ZIO_PRIORITY_ASYNC_WRITE, ZIO_FLAG_MUSTSUCCEED, &zb);
2821 mutex_enter(&db->db_mtx);
2822 dr->dt.dl.dr_override_state = DR_NOT_OVERRIDDEN;
2823 zio_write_override(dr->dr_zio, &dr->dt.dl.dr_overridden_by,
2824 dr->dt.dl.dr_copies, dr->dt.dl.dr_nopwrite);
2825 mutex_exit(&db->db_mtx);
2826 } else if (db->db_state == DB_NOFILL) {
2827 ASSERT(zp.zp_checksum == ZIO_CHECKSUM_OFF ||
2828 zp.zp_checksum == ZIO_CHECKSUM_NOPARITY);
2829 dr->dr_zio = zio_write(zio, os->os_spa, txg,
2830 db->db_blkptr, NULL, db->db.db_size, &zp,
2831 dbuf_write_nofill_ready, NULL, dbuf_write_nofill_done, db,
2832 ZIO_PRIORITY_ASYNC_WRITE,
2833 ZIO_FLAG_MUSTSUCCEED | ZIO_FLAG_NODATA, &zb);
2835 ASSERT(arc_released(data));
2836 dr->dr_zio = arc_write(zio, os->os_spa, txg,
2837 db->db_blkptr, data, DBUF_IS_L2CACHEABLE(db),
2838 DBUF_IS_L2COMPRESSIBLE(db), &zp, dbuf_write_ready,
2839 dbuf_write_physdone, dbuf_write_done, db,
2840 ZIO_PRIORITY_ASYNC_WRITE, ZIO_FLAG_MUSTSUCCEED, &zb);