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/dmu_impl.h>
29 #include <sys/dmu_objset.h>
30 #include <sys/dsl_dataset.h>
31 #include <sys/dsl_dir.h>
32 #include <sys/dmu_tx.h>
35 #include <sys/dmu_zfetch.h>
37 #include <sys/sa_impl.h>
39 static void dbuf_destroy(dmu_buf_impl_t *db);
40 static int dbuf_undirty(dmu_buf_impl_t *db, dmu_tx_t *tx);
41 static void dbuf_write(dbuf_dirty_record_t *dr, arc_buf_t *data, dmu_tx_t *tx);
44 * Global data structures and functions for the dbuf cache.
46 static kmem_cache_t *dbuf_cache;
50 dbuf_cons(void *vdb, void *unused, int kmflag)
52 dmu_buf_impl_t *db = vdb;
53 bzero(db, sizeof (dmu_buf_impl_t));
55 mutex_init(&db->db_mtx, NULL, MUTEX_DEFAULT, NULL);
56 cv_init(&db->db_changed, NULL, CV_DEFAULT, NULL);
57 refcount_create(&db->db_holds);
63 dbuf_dest(void *vdb, void *unused)
65 dmu_buf_impl_t *db = vdb;
66 mutex_destroy(&db->db_mtx);
67 cv_destroy(&db->db_changed);
68 refcount_destroy(&db->db_holds);
72 * dbuf hash table routines
74 static dbuf_hash_table_t dbuf_hash_table;
76 static uint64_t dbuf_hash_count;
79 dbuf_hash(void *os, uint64_t obj, uint8_t lvl, uint64_t blkid)
81 uintptr_t osv = (uintptr_t)os;
84 ASSERT(zfs_crc64_table[128] == ZFS_CRC64_POLY);
85 crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (lvl)) & 0xFF];
86 crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (osv >> 6)) & 0xFF];
87 crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (obj >> 0)) & 0xFF];
88 crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (obj >> 8)) & 0xFF];
89 crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (blkid >> 0)) & 0xFF];
90 crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (blkid >> 8)) & 0xFF];
92 crc ^= (osv>>14) ^ (obj>>16) ^ (blkid>>16);
97 #define DBUF_HASH(os, obj, level, blkid) dbuf_hash(os, obj, level, blkid);
99 #define DBUF_EQUAL(dbuf, os, obj, level, blkid) \
100 ((dbuf)->db.db_object == (obj) && \
101 (dbuf)->db_objset == (os) && \
102 (dbuf)->db_level == (level) && \
103 (dbuf)->db_blkid == (blkid))
106 dbuf_find(dnode_t *dn, uint8_t level, uint64_t blkid)
108 dbuf_hash_table_t *h = &dbuf_hash_table;
109 objset_t *os = dn->dn_objset;
110 uint64_t obj = dn->dn_object;
111 uint64_t hv = DBUF_HASH(os, obj, level, blkid);
112 uint64_t idx = hv & h->hash_table_mask;
115 mutex_enter(DBUF_HASH_MUTEX(h, idx));
116 for (db = h->hash_table[idx]; db != NULL; db = db->db_hash_next) {
117 if (DBUF_EQUAL(db, os, obj, level, blkid)) {
118 mutex_enter(&db->db_mtx);
119 if (db->db_state != DB_EVICTING) {
120 mutex_exit(DBUF_HASH_MUTEX(h, idx));
123 mutex_exit(&db->db_mtx);
126 mutex_exit(DBUF_HASH_MUTEX(h, idx));
131 * Insert an entry into the hash table. If there is already an element
132 * equal to elem in the hash table, then the already existing element
133 * will be returned and the new element will not be inserted.
134 * Otherwise returns NULL.
136 static dmu_buf_impl_t *
137 dbuf_hash_insert(dmu_buf_impl_t *db)
139 dbuf_hash_table_t *h = &dbuf_hash_table;
140 objset_t *os = db->db_objset;
141 uint64_t obj = db->db.db_object;
142 int level = db->db_level;
143 uint64_t blkid = db->db_blkid;
144 uint64_t hv = DBUF_HASH(os, obj, level, blkid);
145 uint64_t idx = hv & h->hash_table_mask;
148 mutex_enter(DBUF_HASH_MUTEX(h, idx));
149 for (dbf = h->hash_table[idx]; dbf != NULL; dbf = dbf->db_hash_next) {
150 if (DBUF_EQUAL(dbf, os, obj, level, blkid)) {
151 mutex_enter(&dbf->db_mtx);
152 if (dbf->db_state != DB_EVICTING) {
153 mutex_exit(DBUF_HASH_MUTEX(h, idx));
156 mutex_exit(&dbf->db_mtx);
160 mutex_enter(&db->db_mtx);
161 db->db_hash_next = h->hash_table[idx];
162 h->hash_table[idx] = db;
163 mutex_exit(DBUF_HASH_MUTEX(h, idx));
164 atomic_add_64(&dbuf_hash_count, 1);
170 * Remove an entry from the hash table. This operation will
171 * fail if there are any existing holds on the db.
174 dbuf_hash_remove(dmu_buf_impl_t *db)
176 dbuf_hash_table_t *h = &dbuf_hash_table;
177 uint64_t hv = DBUF_HASH(db->db_objset, db->db.db_object,
178 db->db_level, db->db_blkid);
179 uint64_t idx = hv & h->hash_table_mask;
180 dmu_buf_impl_t *dbf, **dbp;
183 * We musn't hold db_mtx to maintin lock ordering:
184 * DBUF_HASH_MUTEX > db_mtx.
186 ASSERT(refcount_is_zero(&db->db_holds));
187 ASSERT(db->db_state == DB_EVICTING);
188 ASSERT(!MUTEX_HELD(&db->db_mtx));
190 mutex_enter(DBUF_HASH_MUTEX(h, idx));
191 dbp = &h->hash_table[idx];
192 while ((dbf = *dbp) != db) {
193 dbp = &dbf->db_hash_next;
196 *dbp = db->db_hash_next;
197 db->db_hash_next = NULL;
198 mutex_exit(DBUF_HASH_MUTEX(h, idx));
199 atomic_add_64(&dbuf_hash_count, -1);
202 static arc_evict_func_t dbuf_do_evict;
205 dbuf_evict_user(dmu_buf_impl_t *db)
207 ASSERT(MUTEX_HELD(&db->db_mtx));
209 if (db->db_level != 0 || db->db_evict_func == NULL)
212 if (db->db_user_data_ptr_ptr)
213 *db->db_user_data_ptr_ptr = db->db.db_data;
214 db->db_evict_func(&db->db, db->db_user_ptr);
215 db->db_user_ptr = NULL;
216 db->db_user_data_ptr_ptr = NULL;
217 db->db_evict_func = NULL;
221 dbuf_evict(dmu_buf_impl_t *db)
223 ASSERT(MUTEX_HELD(&db->db_mtx));
224 ASSERT(db->db_buf == NULL);
225 ASSERT(db->db_data_pending == NULL);
234 uint64_t hsize = 1ULL << 16;
235 dbuf_hash_table_t *h = &dbuf_hash_table;
239 * The hash table is big enough to fill all of physical memory
240 * with an average 4K block size. The table will take up
241 * totalmem*sizeof(void*)/4K (i.e. 2MB/GB with 8-byte pointers).
243 while (hsize * 4096 < physmem * PAGESIZE)
247 h->hash_table_mask = hsize - 1;
248 h->hash_table = kmem_zalloc(hsize * sizeof (void *), KM_NOSLEEP);
249 if (h->hash_table == NULL) {
250 /* XXX - we should really return an error instead of assert */
251 ASSERT(hsize > (1ULL << 10));
256 dbuf_cache = kmem_cache_create("dmu_buf_impl_t",
257 sizeof (dmu_buf_impl_t),
258 0, dbuf_cons, dbuf_dest, NULL, NULL, NULL, 0);
260 for (i = 0; i < DBUF_MUTEXES; i++)
261 mutex_init(&h->hash_mutexes[i], NULL, MUTEX_DEFAULT, NULL);
267 dbuf_hash_table_t *h = &dbuf_hash_table;
270 for (i = 0; i < DBUF_MUTEXES; i++)
271 mutex_destroy(&h->hash_mutexes[i]);
272 kmem_free(h->hash_table, (h->hash_table_mask + 1) * sizeof (void *));
273 kmem_cache_destroy(dbuf_cache);
282 dbuf_verify(dmu_buf_impl_t *db)
284 dnode_t *dn = db->db_dnode;
285 dbuf_dirty_record_t *dr;
287 ASSERT(MUTEX_HELD(&db->db_mtx));
289 if (!(zfs_flags & ZFS_DEBUG_DBUF_VERIFY))
292 ASSERT(db->db_objset != NULL);
294 ASSERT(db->db_parent == NULL);
295 ASSERT(db->db_blkptr == NULL);
297 ASSERT3U(db->db.db_object, ==, dn->dn_object);
298 ASSERT3P(db->db_objset, ==, dn->dn_objset);
299 ASSERT3U(db->db_level, <, dn->dn_nlevels);
300 ASSERT(db->db_blkid == DMU_BONUS_BLKID || db->db_blkid ==
301 DMU_SPILL_BLKID || list_head(&dn->dn_dbufs));
303 if (db->db_blkid == DMU_BONUS_BLKID) {
305 ASSERT3U(db->db.db_size, >=, dn->dn_bonuslen);
306 ASSERT3U(db->db.db_offset, ==, DMU_BONUS_BLKID);
307 } else if (db->db_blkid == DMU_SPILL_BLKID) {
309 ASSERT3U(db->db.db_size, >=, dn->dn_bonuslen);
310 ASSERT3U(db->db.db_offset, ==, 0);
312 ASSERT3U(db->db.db_offset, ==, db->db_blkid * db->db.db_size);
315 for (dr = db->db_data_pending; dr != NULL; dr = dr->dr_next)
316 ASSERT(dr->dr_dbuf == db);
318 for (dr = db->db_last_dirty; dr != NULL; dr = dr->dr_next)
319 ASSERT(dr->dr_dbuf == db);
322 * We can't assert that db_size matches dn_datablksz because it
323 * can be momentarily different when another thread is doing
326 if (db->db_level == 0 && db->db.db_object == DMU_META_DNODE_OBJECT) {
327 dr = db->db_data_pending;
329 * It should only be modified in syncing context, so
330 * make sure we only have one copy of the data.
332 ASSERT(dr == NULL || dr->dt.dl.dr_data == db->db_buf);
335 /* verify db->db_blkptr */
337 if (db->db_parent == dn->dn_dbuf) {
338 /* db is pointed to by the dnode */
339 /* ASSERT3U(db->db_blkid, <, dn->dn_nblkptr); */
340 if (DMU_OBJECT_IS_SPECIAL(db->db.db_object))
341 ASSERT(db->db_parent == NULL);
343 ASSERT(db->db_parent != NULL);
344 if (db->db_blkid != DMU_SPILL_BLKID)
345 ASSERT3P(db->db_blkptr, ==,
346 &dn->dn_phys->dn_blkptr[db->db_blkid]);
348 /* db is pointed to by an indirect block */
349 int epb = db->db_parent->db.db_size >> SPA_BLKPTRSHIFT;
350 ASSERT3U(db->db_parent->db_level, ==, db->db_level+1);
351 ASSERT3U(db->db_parent->db.db_object, ==,
354 * dnode_grow_indblksz() can make this fail if we don't
355 * have the struct_rwlock. XXX indblksz no longer
356 * grows. safe to do this now?
358 if (RW_WRITE_HELD(&db->db_dnode->dn_struct_rwlock)) {
359 ASSERT3P(db->db_blkptr, ==,
360 ((blkptr_t *)db->db_parent->db.db_data +
361 db->db_blkid % epb));
365 if ((db->db_blkptr == NULL || BP_IS_HOLE(db->db_blkptr)) &&
366 (db->db_buf == NULL || db->db_buf->b_data) &&
367 db->db.db_data && db->db_blkid != DMU_BONUS_BLKID &&
368 db->db_state != DB_FILL && !dn->dn_free_txg) {
370 * If the blkptr isn't set but they have nonzero data,
371 * it had better be dirty, otherwise we'll lose that
372 * data when we evict this buffer.
374 if (db->db_dirtycnt == 0) {
375 uint64_t *buf = db->db.db_data;
378 for (i = 0; i < db->db.db_size >> 3; i++) {
387 dbuf_update_data(dmu_buf_impl_t *db)
389 ASSERT(MUTEX_HELD(&db->db_mtx));
390 if (db->db_level == 0 && db->db_user_data_ptr_ptr) {
391 ASSERT(!refcount_is_zero(&db->db_holds));
392 *db->db_user_data_ptr_ptr = db->db.db_data;
397 dbuf_set_data(dmu_buf_impl_t *db, arc_buf_t *buf)
399 ASSERT(MUTEX_HELD(&db->db_mtx));
400 ASSERT(db->db_buf == NULL || !arc_has_callback(db->db_buf));
403 ASSERT(buf->b_data != NULL);
404 db->db.db_data = buf->b_data;
405 if (!arc_released(buf))
406 arc_set_callback(buf, dbuf_do_evict, db);
407 dbuf_update_data(db);
410 db->db.db_data = NULL;
411 if (db->db_state != DB_NOFILL)
412 db->db_state = DB_UNCACHED;
417 * Loan out an arc_buf for read. Return the loaned arc_buf.
420 dbuf_loan_arcbuf(dmu_buf_impl_t *db)
424 mutex_enter(&db->db_mtx);
425 if (arc_released(db->db_buf) || refcount_count(&db->db_holds) > 1) {
426 int blksz = db->db.db_size;
427 mutex_exit(&db->db_mtx);
428 abuf = arc_loan_buf(db->db_dnode->dn_objset->os_spa, blksz);
429 bcopy(db->db.db_data, abuf->b_data, blksz);
432 arc_loan_inuse_buf(abuf, db);
433 dbuf_set_data(db, NULL);
434 mutex_exit(&db->db_mtx);
440 dbuf_whichblock(dnode_t *dn, uint64_t offset)
442 if (dn->dn_datablkshift) {
443 return (offset >> dn->dn_datablkshift);
445 ASSERT3U(offset, <, dn->dn_datablksz);
451 dbuf_read_done(zio_t *zio, arc_buf_t *buf, void *vdb)
453 dmu_buf_impl_t *db = vdb;
455 mutex_enter(&db->db_mtx);
456 ASSERT3U(db->db_state, ==, DB_READ);
458 * All reads are synchronous, so we must have a hold on the dbuf
460 ASSERT(refcount_count(&db->db_holds) > 0);
461 ASSERT(db->db_buf == NULL);
462 ASSERT(db->db.db_data == NULL);
463 if (db->db_level == 0 && db->db_freed_in_flight) {
464 /* we were freed in flight; disregard any error */
465 arc_release(buf, db);
466 bzero(buf->b_data, db->db.db_size);
468 db->db_freed_in_flight = FALSE;
469 dbuf_set_data(db, buf);
470 db->db_state = DB_CACHED;
471 } else if (zio == NULL || zio->io_error == 0) {
472 dbuf_set_data(db, buf);
473 db->db_state = DB_CACHED;
475 ASSERT(db->db_blkid != DMU_BONUS_BLKID);
476 ASSERT3P(db->db_buf, ==, NULL);
477 VERIFY(arc_buf_remove_ref(buf, db) == 1);
478 db->db_state = DB_UNCACHED;
480 cv_broadcast(&db->db_changed);
481 dbuf_rele_and_unlock(db, NULL);
485 dbuf_read_impl(dmu_buf_impl_t *db, zio_t *zio, uint32_t *flags)
487 dnode_t *dn = db->db_dnode;
489 uint32_t aflags = ARC_NOWAIT;
492 ASSERT(!refcount_is_zero(&db->db_holds));
493 /* We need the struct_rwlock to prevent db_blkptr from changing. */
494 ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock));
495 ASSERT(MUTEX_HELD(&db->db_mtx));
496 ASSERT(db->db_state == DB_UNCACHED);
497 ASSERT(db->db_buf == NULL);
499 if (db->db_blkid == DMU_BONUS_BLKID) {
500 int bonuslen = MIN(dn->dn_bonuslen, dn->dn_phys->dn_bonuslen);
502 ASSERT3U(bonuslen, <=, db->db.db_size);
503 db->db.db_data = zio_buf_alloc(DN_MAX_BONUSLEN);
504 arc_space_consume(DN_MAX_BONUSLEN, ARC_SPACE_OTHER);
505 if (bonuslen < DN_MAX_BONUSLEN)
506 bzero(db->db.db_data, DN_MAX_BONUSLEN);
508 bcopy(DN_BONUS(dn->dn_phys), db->db.db_data, bonuslen);
509 dbuf_update_data(db);
510 db->db_state = DB_CACHED;
511 mutex_exit(&db->db_mtx);
516 * Recheck BP_IS_HOLE() after dnode_block_freed() in case dnode_sync()
517 * processes the delete record and clears the bp while we are waiting
518 * for the dn_mtx (resulting in a "no" from block_freed).
520 if (db->db_blkptr == NULL || BP_IS_HOLE(db->db_blkptr) ||
521 (db->db_level == 0 && (dnode_block_freed(dn, db->db_blkid) ||
522 BP_IS_HOLE(db->db_blkptr)))) {
523 arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db);
525 dbuf_set_data(db, arc_buf_alloc(dn->dn_objset->os_spa,
526 db->db.db_size, db, type));
527 bzero(db->db.db_data, db->db.db_size);
528 db->db_state = DB_CACHED;
529 *flags |= DB_RF_CACHED;
530 mutex_exit(&db->db_mtx);
534 db->db_state = DB_READ;
535 mutex_exit(&db->db_mtx);
537 if (DBUF_IS_L2CACHEABLE(db))
538 aflags |= ARC_L2CACHE;
540 SET_BOOKMARK(&zb, db->db_objset->os_dsl_dataset ?
541 db->db_objset->os_dsl_dataset->ds_object : DMU_META_OBJSET,
542 db->db.db_object, db->db_level, db->db_blkid);
544 dbuf_add_ref(db, NULL);
545 /* ZIO_FLAG_CANFAIL callers have to check the parent zio's error */
548 pbuf = db->db_parent->db_buf;
550 pbuf = db->db_objset->os_phys_buf;
552 (void) dsl_read(zio, dn->dn_objset->os_spa, db->db_blkptr, pbuf,
553 dbuf_read_done, db, ZIO_PRIORITY_SYNC_READ,
554 (*flags & DB_RF_CANFAIL) ? ZIO_FLAG_CANFAIL : ZIO_FLAG_MUSTSUCCEED,
556 if (aflags & ARC_CACHED)
557 *flags |= DB_RF_CACHED;
561 dbuf_read(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags)
564 int havepzio = (zio != NULL);
568 * We don't have to hold the mutex to check db_state because it
569 * can't be freed while we have a hold on the buffer.
571 ASSERT(!refcount_is_zero(&db->db_holds));
573 if (db->db_state == DB_NOFILL)
576 if ((flags & DB_RF_HAVESTRUCT) == 0)
577 rw_enter(&db->db_dnode->dn_struct_rwlock, RW_READER);
579 prefetch = db->db_level == 0 && db->db_blkid != DMU_BONUS_BLKID &&
580 (flags & DB_RF_NOPREFETCH) == 0 && db->db_dnode != NULL &&
581 DBUF_IS_CACHEABLE(db);
583 mutex_enter(&db->db_mtx);
584 if (db->db_state == DB_CACHED) {
585 mutex_exit(&db->db_mtx);
587 dmu_zfetch(&db->db_dnode->dn_zfetch, db->db.db_offset,
588 db->db.db_size, TRUE);
589 if ((flags & DB_RF_HAVESTRUCT) == 0)
590 rw_exit(&db->db_dnode->dn_struct_rwlock);
591 } else if (db->db_state == DB_UNCACHED) {
593 zio = zio_root(db->db_dnode->dn_objset->os_spa,
594 NULL, NULL, ZIO_FLAG_CANFAIL);
596 dbuf_read_impl(db, zio, &flags);
598 /* dbuf_read_impl has dropped db_mtx for us */
601 dmu_zfetch(&db->db_dnode->dn_zfetch, db->db.db_offset,
602 db->db.db_size, flags & DB_RF_CACHED);
604 if ((flags & DB_RF_HAVESTRUCT) == 0)
605 rw_exit(&db->db_dnode->dn_struct_rwlock);
610 mutex_exit(&db->db_mtx);
612 dmu_zfetch(&db->db_dnode->dn_zfetch, db->db.db_offset,
613 db->db.db_size, TRUE);
614 if ((flags & DB_RF_HAVESTRUCT) == 0)
615 rw_exit(&db->db_dnode->dn_struct_rwlock);
617 mutex_enter(&db->db_mtx);
618 if ((flags & DB_RF_NEVERWAIT) == 0) {
619 while (db->db_state == DB_READ ||
620 db->db_state == DB_FILL) {
621 ASSERT(db->db_state == DB_READ ||
622 (flags & DB_RF_HAVESTRUCT) == 0);
623 cv_wait(&db->db_changed, &db->db_mtx);
625 if (db->db_state == DB_UNCACHED)
628 mutex_exit(&db->db_mtx);
631 ASSERT(err || havepzio || db->db_state == DB_CACHED);
636 dbuf_noread(dmu_buf_impl_t *db)
638 ASSERT(!refcount_is_zero(&db->db_holds));
639 ASSERT(db->db_blkid != DMU_BONUS_BLKID);
640 mutex_enter(&db->db_mtx);
641 while (db->db_state == DB_READ || db->db_state == DB_FILL)
642 cv_wait(&db->db_changed, &db->db_mtx);
643 if (db->db_state == DB_UNCACHED) {
644 arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db);
646 ASSERT(db->db_buf == NULL);
647 ASSERT(db->db.db_data == NULL);
648 dbuf_set_data(db, arc_buf_alloc(db->db_dnode->dn_objset->os_spa,
649 db->db.db_size, db, type));
650 db->db_state = DB_FILL;
651 } else if (db->db_state == DB_NOFILL) {
652 dbuf_set_data(db, NULL);
654 ASSERT3U(db->db_state, ==, DB_CACHED);
656 mutex_exit(&db->db_mtx);
660 * This is our just-in-time copy function. It makes a copy of
661 * buffers, that have been modified in a previous transaction
662 * group, before we modify them in the current active group.
664 * This function is used in two places: when we are dirtying a
665 * buffer for the first time in a txg, and when we are freeing
666 * a range in a dnode that includes this buffer.
668 * Note that when we are called from dbuf_free_range() we do
669 * not put a hold on the buffer, we just traverse the active
670 * dbuf list for the dnode.
673 dbuf_fix_old_data(dmu_buf_impl_t *db, uint64_t txg)
675 dbuf_dirty_record_t *dr = db->db_last_dirty;
677 ASSERT(MUTEX_HELD(&db->db_mtx));
678 ASSERT(db->db.db_data != NULL);
679 ASSERT(db->db_level == 0);
680 ASSERT(db->db.db_object != DMU_META_DNODE_OBJECT);
683 (dr->dt.dl.dr_data !=
684 ((db->db_blkid == DMU_BONUS_BLKID) ? db->db.db_data : db->db_buf)))
688 * If the last dirty record for this dbuf has not yet synced
689 * and its referencing the dbuf data, either:
690 * reset the reference to point to a new copy,
691 * or (if there a no active holders)
692 * just null out the current db_data pointer.
694 ASSERT(dr->dr_txg >= txg - 2);
695 if (db->db_blkid == DMU_BONUS_BLKID) {
696 /* Note that the data bufs here are zio_bufs */
697 dr->dt.dl.dr_data = zio_buf_alloc(DN_MAX_BONUSLEN);
698 arc_space_consume(DN_MAX_BONUSLEN, ARC_SPACE_OTHER);
699 bcopy(db->db.db_data, dr->dt.dl.dr_data, DN_MAX_BONUSLEN);
700 } else if (refcount_count(&db->db_holds) > db->db_dirtycnt) {
701 int size = db->db.db_size;
702 arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db);
703 dr->dt.dl.dr_data = arc_buf_alloc(
704 db->db_dnode->dn_objset->os_spa, size, db, type);
705 bcopy(db->db.db_data, dr->dt.dl.dr_data->b_data, size);
707 dbuf_set_data(db, NULL);
712 dbuf_unoverride(dbuf_dirty_record_t *dr)
714 dmu_buf_impl_t *db = dr->dr_dbuf;
715 blkptr_t *bp = &dr->dt.dl.dr_overridden_by;
716 uint64_t txg = dr->dr_txg;
718 ASSERT(MUTEX_HELD(&db->db_mtx));
719 ASSERT(dr->dt.dl.dr_override_state != DR_IN_DMU_SYNC);
720 ASSERT(db->db_level == 0);
722 if (db->db_blkid == DMU_BONUS_BLKID ||
723 dr->dt.dl.dr_override_state == DR_NOT_OVERRIDDEN)
726 ASSERT(db->db_data_pending != dr);
728 /* free this block */
730 zio_free(db->db_dnode->dn_objset->os_spa, txg, bp);
732 dr->dt.dl.dr_override_state = DR_NOT_OVERRIDDEN;
734 * Release the already-written buffer, so we leave it in
735 * a consistent dirty state. Note that all callers are
736 * modifying the buffer, so they will immediately do
737 * another (redundant) arc_release(). Therefore, leave
738 * the buf thawed to save the effort of freezing &
739 * immediately re-thawing it.
741 arc_release(dr->dt.dl.dr_data, db);
745 * Evict (if its unreferenced) or clear (if its referenced) any level-0
746 * data blocks in the free range, so that any future readers will find
747 * empty blocks. Also, if we happen accross any level-1 dbufs in the
748 * range that have not already been marked dirty, mark them dirty so
749 * they stay in memory.
752 dbuf_free_range(dnode_t *dn, uint64_t start, uint64_t end, dmu_tx_t *tx)
754 dmu_buf_impl_t *db, *db_next;
755 uint64_t txg = tx->tx_txg;
756 int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
757 uint64_t first_l1 = start >> epbs;
758 uint64_t last_l1 = end >> epbs;
760 if (end > dn->dn_maxblkid && (end != DMU_SPILL_BLKID)) {
761 end = dn->dn_maxblkid;
762 last_l1 = end >> epbs;
764 dprintf_dnode(dn, "start=%llu end=%llu\n", start, end);
765 mutex_enter(&dn->dn_dbufs_mtx);
766 for (db = list_head(&dn->dn_dbufs); db; db = db_next) {
767 db_next = list_next(&dn->dn_dbufs, db);
768 ASSERT(db->db_blkid != DMU_BONUS_BLKID);
770 if (db->db_level == 1 &&
771 db->db_blkid >= first_l1 && db->db_blkid <= last_l1) {
772 mutex_enter(&db->db_mtx);
773 if (db->db_last_dirty &&
774 db->db_last_dirty->dr_txg < txg) {
775 dbuf_add_ref(db, FTAG);
776 mutex_exit(&db->db_mtx);
777 dbuf_will_dirty(db, tx);
780 mutex_exit(&db->db_mtx);
784 if (db->db_level != 0)
786 dprintf_dbuf(db, "found buf %s\n", "");
787 if (db->db_blkid < start || db->db_blkid > end)
790 /* found a level 0 buffer in the range */
791 if (dbuf_undirty(db, tx))
794 mutex_enter(&db->db_mtx);
795 if (db->db_state == DB_UNCACHED ||
796 db->db_state == DB_NOFILL ||
797 db->db_state == DB_EVICTING) {
798 ASSERT(db->db.db_data == NULL);
799 mutex_exit(&db->db_mtx);
802 if (db->db_state == DB_READ || db->db_state == DB_FILL) {
803 /* will be handled in dbuf_read_done or dbuf_rele */
804 db->db_freed_in_flight = TRUE;
805 mutex_exit(&db->db_mtx);
808 if (refcount_count(&db->db_holds) == 0) {
813 /* The dbuf is referenced */
815 if (db->db_last_dirty != NULL) {
816 dbuf_dirty_record_t *dr = db->db_last_dirty;
818 if (dr->dr_txg == txg) {
820 * This buffer is "in-use", re-adjust the file
821 * size to reflect that this buffer may
822 * contain new data when we sync.
824 if (db->db_blkid != DMU_SPILL_BLKID &&
825 db->db_blkid > dn->dn_maxblkid)
826 dn->dn_maxblkid = db->db_blkid;
830 * This dbuf is not dirty in the open context.
831 * Either uncache it (if its not referenced in
832 * the open context) or reset its contents to
835 dbuf_fix_old_data(db, txg);
838 /* clear the contents if its cached */
839 if (db->db_state == DB_CACHED) {
840 ASSERT(db->db.db_data != NULL);
841 arc_release(db->db_buf, db);
842 bzero(db->db.db_data, db->db.db_size);
843 arc_buf_freeze(db->db_buf);
846 mutex_exit(&db->db_mtx);
848 mutex_exit(&dn->dn_dbufs_mtx);
852 dbuf_block_freeable(dmu_buf_impl_t *db)
854 dsl_dataset_t *ds = db->db_objset->os_dsl_dataset;
855 uint64_t birth_txg = 0;
858 * We don't need any locking to protect db_blkptr:
859 * If it's syncing, then db_last_dirty will be set
860 * so we'll ignore db_blkptr.
862 ASSERT(MUTEX_HELD(&db->db_mtx));
863 if (db->db_last_dirty)
864 birth_txg = db->db_last_dirty->dr_txg;
865 else if (db->db_blkptr)
866 birth_txg = db->db_blkptr->blk_birth;
868 /* If we don't exist or are in a snapshot, we can't be freed */
870 return (ds == NULL ||
871 dsl_dataset_block_freeable(ds, db->db_blkptr, birth_txg));
877 dbuf_new_size(dmu_buf_impl_t *db, int size, dmu_tx_t *tx)
879 arc_buf_t *buf, *obuf;
880 int osize = db->db.db_size;
881 arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db);
883 ASSERT(db->db_blkid != DMU_BONUS_BLKID);
885 /* XXX does *this* func really need the lock? */
886 ASSERT(RW_WRITE_HELD(&db->db_dnode->dn_struct_rwlock));
889 * This call to dbuf_will_dirty() with the dn_struct_rwlock held
890 * is OK, because there can be no other references to the db
891 * when we are changing its size, so no concurrent DB_FILL can
895 * XXX we should be doing a dbuf_read, checking the return
896 * value and returning that up to our callers
898 dbuf_will_dirty(db, tx);
900 /* create the data buffer for the new block */
901 buf = arc_buf_alloc(db->db_dnode->dn_objset->os_spa, size, db, type);
903 /* copy old block data to the new block */
905 bcopy(obuf->b_data, buf->b_data, MIN(osize, size));
906 /* zero the remainder */
908 bzero((uint8_t *)buf->b_data + osize, size - osize);
910 mutex_enter(&db->db_mtx);
911 dbuf_set_data(db, buf);
912 VERIFY(arc_buf_remove_ref(obuf, db) == 1);
913 db->db.db_size = size;
915 if (db->db_level == 0) {
916 ASSERT3U(db->db_last_dirty->dr_txg, ==, tx->tx_txg);
917 db->db_last_dirty->dt.dl.dr_data = buf;
919 mutex_exit(&db->db_mtx);
921 dnode_willuse_space(db->db_dnode, size-osize, tx);
925 dbuf_release_bp(dmu_buf_impl_t *db)
927 objset_t *os = db->db_dnode->dn_objset;
930 ASSERT(dsl_pool_sync_context(dmu_objset_pool(os)));
931 ASSERT(arc_released(os->os_phys_buf) ||
932 list_link_active(&os->os_dsl_dataset->ds_synced_link));
933 ASSERT(db->db_parent == NULL || arc_released(db->db_parent->db_buf));
935 zb.zb_objset = os->os_dsl_dataset ?
936 os->os_dsl_dataset->ds_object : 0;
937 zb.zb_object = db->db.db_object;
938 zb.zb_level = db->db_level;
939 zb.zb_blkid = db->db_blkid;
940 (void) arc_release_bp(db->db_buf, db,
941 db->db_blkptr, os->os_spa, &zb);
944 dbuf_dirty_record_t *
945 dbuf_dirty(dmu_buf_impl_t *db, dmu_tx_t *tx)
947 dnode_t *dn = db->db_dnode;
948 objset_t *os = dn->dn_objset;
949 dbuf_dirty_record_t **drp, *dr;
950 int drop_struct_lock = FALSE;
951 boolean_t do_free_accounting = B_FALSE;
952 int txgoff = tx->tx_txg & TXG_MASK;
954 ASSERT(tx->tx_txg != 0);
955 ASSERT(!refcount_is_zero(&db->db_holds));
956 DMU_TX_DIRTY_BUF(tx, db);
959 * Shouldn't dirty a regular buffer in syncing context. Private
960 * objects may be dirtied in syncing context, but only if they
961 * were already pre-dirtied in open context.
963 ASSERT(!dmu_tx_is_syncing(tx) ||
964 BP_IS_HOLE(dn->dn_objset->os_rootbp) ||
965 DMU_OBJECT_IS_SPECIAL(dn->dn_object) ||
966 dn->dn_objset->os_dsl_dataset == NULL);
968 * We make this assert for private objects as well, but after we
969 * check if we're already dirty. They are allowed to re-dirty
970 * in syncing context.
972 ASSERT(dn->dn_object == DMU_META_DNODE_OBJECT ||
973 dn->dn_dirtyctx == DN_UNDIRTIED || dn->dn_dirtyctx ==
974 (dmu_tx_is_syncing(tx) ? DN_DIRTY_SYNC : DN_DIRTY_OPEN));
976 mutex_enter(&db->db_mtx);
978 * XXX make this true for indirects too? The problem is that
979 * transactions created with dmu_tx_create_assigned() from
980 * syncing context don't bother holding ahead.
982 ASSERT(db->db_level != 0 ||
983 db->db_state == DB_CACHED || db->db_state == DB_FILL ||
984 db->db_state == DB_NOFILL);
986 mutex_enter(&dn->dn_mtx);
988 * Don't set dirtyctx to SYNC if we're just modifying this as we
989 * initialize the objset.
991 if (dn->dn_dirtyctx == DN_UNDIRTIED &&
992 !BP_IS_HOLE(dn->dn_objset->os_rootbp)) {
994 (dmu_tx_is_syncing(tx) ? DN_DIRTY_SYNC : DN_DIRTY_OPEN);
995 ASSERT(dn->dn_dirtyctx_firstset == NULL);
996 dn->dn_dirtyctx_firstset = kmem_alloc(1, KM_SLEEP);
998 mutex_exit(&dn->dn_mtx);
1000 if (db->db_blkid == DMU_SPILL_BLKID)
1001 dn->dn_have_spill = B_TRUE;
1004 * If this buffer is already dirty, we're done.
1006 drp = &db->db_last_dirty;
1007 ASSERT(*drp == NULL || (*drp)->dr_txg <= tx->tx_txg ||
1008 db->db.db_object == DMU_META_DNODE_OBJECT);
1009 while ((dr = *drp) != NULL && dr->dr_txg > tx->tx_txg)
1011 if (dr && dr->dr_txg == tx->tx_txg) {
1012 if (db->db_level == 0 && db->db_blkid != DMU_BONUS_BLKID) {
1014 * If this buffer has already been written out,
1015 * we now need to reset its state.
1017 dbuf_unoverride(dr);
1018 if (db->db.db_object != DMU_META_DNODE_OBJECT &&
1019 db->db_state != DB_NOFILL)
1020 arc_buf_thaw(db->db_buf);
1022 mutex_exit(&db->db_mtx);
1027 * Only valid if not already dirty.
1029 ASSERT(dn->dn_object == 0 ||
1030 dn->dn_dirtyctx == DN_UNDIRTIED || dn->dn_dirtyctx ==
1031 (dmu_tx_is_syncing(tx) ? DN_DIRTY_SYNC : DN_DIRTY_OPEN));
1033 ASSERT3U(dn->dn_nlevels, >, db->db_level);
1034 ASSERT((dn->dn_phys->dn_nlevels == 0 && db->db_level == 0) ||
1035 dn->dn_phys->dn_nlevels > db->db_level ||
1036 dn->dn_next_nlevels[txgoff] > db->db_level ||
1037 dn->dn_next_nlevels[(tx->tx_txg-1) & TXG_MASK] > db->db_level ||
1038 dn->dn_next_nlevels[(tx->tx_txg-2) & TXG_MASK] > db->db_level);
1041 * We should only be dirtying in syncing context if it's the
1042 * mos or we're initializing the os or it's a special object.
1043 * However, we are allowed to dirty in syncing context provided
1044 * we already dirtied it in open context. Hence we must make
1045 * this assertion only if we're not already dirty.
1047 ASSERT(!dmu_tx_is_syncing(tx) || DMU_OBJECT_IS_SPECIAL(dn->dn_object) ||
1048 os->os_dsl_dataset == NULL || BP_IS_HOLE(os->os_rootbp));
1049 ASSERT(db->db.db_size != 0);
1051 dprintf_dbuf(db, "size=%llx\n", (u_longlong_t)db->db.db_size);
1053 if (db->db_blkid != DMU_BONUS_BLKID) {
1055 * Update the accounting.
1056 * Note: we delay "free accounting" until after we drop
1057 * the db_mtx. This keeps us from grabbing other locks
1058 * (and possibly deadlocking) in bp_get_dsize() while
1059 * also holding the db_mtx.
1061 dnode_willuse_space(dn, db->db.db_size, tx);
1062 do_free_accounting = dbuf_block_freeable(db);
1066 * If this buffer is dirty in an old transaction group we need
1067 * to make a copy of it so that the changes we make in this
1068 * transaction group won't leak out when we sync the older txg.
1070 dr = kmem_zalloc(sizeof (dbuf_dirty_record_t), KM_SLEEP);
1071 if (db->db_level == 0) {
1072 void *data_old = db->db_buf;
1074 if (db->db_state != DB_NOFILL) {
1075 if (db->db_blkid == DMU_BONUS_BLKID) {
1076 dbuf_fix_old_data(db, tx->tx_txg);
1077 data_old = db->db.db_data;
1078 } else if (db->db.db_object != DMU_META_DNODE_OBJECT) {
1080 * Release the data buffer from the cache so
1081 * that we can modify it without impacting
1082 * possible other users of this cached data
1083 * block. Note that indirect blocks and
1084 * private objects are not released until the
1085 * syncing state (since they are only modified
1088 arc_release(db->db_buf, db);
1089 dbuf_fix_old_data(db, tx->tx_txg);
1090 data_old = db->db_buf;
1092 ASSERT(data_old != NULL);
1094 dr->dt.dl.dr_data = data_old;
1096 mutex_init(&dr->dt.di.dr_mtx, NULL, MUTEX_DEFAULT, NULL);
1097 list_create(&dr->dt.di.dr_children,
1098 sizeof (dbuf_dirty_record_t),
1099 offsetof(dbuf_dirty_record_t, dr_dirty_node));
1102 dr->dr_txg = tx->tx_txg;
1107 * We could have been freed_in_flight between the dbuf_noread
1108 * and dbuf_dirty. We win, as though the dbuf_noread() had
1109 * happened after the free.
1111 if (db->db_level == 0 && db->db_blkid != DMU_BONUS_BLKID &&
1112 db->db_blkid != DMU_SPILL_BLKID) {
1113 mutex_enter(&dn->dn_mtx);
1114 dnode_clear_range(dn, db->db_blkid, 1, tx);
1115 mutex_exit(&dn->dn_mtx);
1116 db->db_freed_in_flight = FALSE;
1120 * This buffer is now part of this txg
1122 dbuf_add_ref(db, (void *)(uintptr_t)tx->tx_txg);
1123 db->db_dirtycnt += 1;
1124 ASSERT3U(db->db_dirtycnt, <=, 3);
1126 mutex_exit(&db->db_mtx);
1128 if (db->db_blkid == DMU_BONUS_BLKID ||
1129 db->db_blkid == DMU_SPILL_BLKID) {
1130 mutex_enter(&dn->dn_mtx);
1131 ASSERT(!list_link_active(&dr->dr_dirty_node));
1132 list_insert_tail(&dn->dn_dirty_records[txgoff], dr);
1133 mutex_exit(&dn->dn_mtx);
1134 dnode_setdirty(dn, tx);
1136 } else if (do_free_accounting) {
1137 blkptr_t *bp = db->db_blkptr;
1138 int64_t willfree = (bp && !BP_IS_HOLE(bp)) ?
1139 bp_get_dsize(os->os_spa, bp) : db->db.db_size;
1141 * This is only a guess -- if the dbuf is dirty
1142 * in a previous txg, we don't know how much
1143 * space it will use on disk yet. We should
1144 * really have the struct_rwlock to access
1145 * db_blkptr, but since this is just a guess,
1146 * it's OK if we get an odd answer.
1148 dnode_willuse_space(dn, -willfree, tx);
1151 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) {
1152 rw_enter(&dn->dn_struct_rwlock, RW_READER);
1153 drop_struct_lock = TRUE;
1156 if (db->db_level == 0) {
1157 dnode_new_blkid(dn, db->db_blkid, tx, drop_struct_lock);
1158 ASSERT(dn->dn_maxblkid >= db->db_blkid);
1161 if (db->db_level+1 < dn->dn_nlevels) {
1162 dmu_buf_impl_t *parent = db->db_parent;
1163 dbuf_dirty_record_t *di;
1164 int parent_held = FALSE;
1166 if (db->db_parent == NULL || db->db_parent == dn->dn_dbuf) {
1167 int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
1169 parent = dbuf_hold_level(dn, db->db_level+1,
1170 db->db_blkid >> epbs, FTAG);
1171 ASSERT(parent != NULL);
1174 if (drop_struct_lock)
1175 rw_exit(&dn->dn_struct_rwlock);
1176 ASSERT3U(db->db_level+1, ==, parent->db_level);
1177 di = dbuf_dirty(parent, tx);
1179 dbuf_rele(parent, FTAG);
1181 mutex_enter(&db->db_mtx);
1182 /* possible race with dbuf_undirty() */
1183 if (db->db_last_dirty == dr ||
1184 dn->dn_object == DMU_META_DNODE_OBJECT) {
1185 mutex_enter(&di->dt.di.dr_mtx);
1186 ASSERT3U(di->dr_txg, ==, tx->tx_txg);
1187 ASSERT(!list_link_active(&dr->dr_dirty_node));
1188 list_insert_tail(&di->dt.di.dr_children, dr);
1189 mutex_exit(&di->dt.di.dr_mtx);
1192 mutex_exit(&db->db_mtx);
1194 ASSERT(db->db_level+1 == dn->dn_nlevels);
1195 ASSERT(db->db_blkid < dn->dn_nblkptr);
1196 ASSERT(db->db_parent == NULL ||
1197 db->db_parent == db->db_dnode->dn_dbuf);
1198 mutex_enter(&dn->dn_mtx);
1199 ASSERT(!list_link_active(&dr->dr_dirty_node));
1200 list_insert_tail(&dn->dn_dirty_records[txgoff], dr);
1201 mutex_exit(&dn->dn_mtx);
1202 if (drop_struct_lock)
1203 rw_exit(&dn->dn_struct_rwlock);
1206 dnode_setdirty(dn, tx);
1211 dbuf_undirty(dmu_buf_impl_t *db, dmu_tx_t *tx)
1213 dnode_t *dn = db->db_dnode;
1214 uint64_t txg = tx->tx_txg;
1215 dbuf_dirty_record_t *dr, **drp;
1218 ASSERT(db->db_blkid != DMU_BONUS_BLKID);
1220 mutex_enter(&db->db_mtx);
1222 * If this buffer is not dirty, we're done.
1224 for (drp = &db->db_last_dirty; (dr = *drp) != NULL; drp = &dr->dr_next)
1225 if (dr->dr_txg <= txg)
1227 if (dr == NULL || dr->dr_txg < txg) {
1228 mutex_exit(&db->db_mtx);
1231 ASSERT(dr->dr_txg == txg);
1232 ASSERT(dr->dr_dbuf == db);
1235 * If this buffer is currently held, we cannot undirty
1236 * it, since one of the current holders may be in the
1237 * middle of an update. Note that users of dbuf_undirty()
1238 * should not place a hold on the dbuf before the call.
1240 if (refcount_count(&db->db_holds) > db->db_dirtycnt) {
1241 mutex_exit(&db->db_mtx);
1242 /* Make sure we don't toss this buffer at sync phase */
1243 mutex_enter(&dn->dn_mtx);
1244 dnode_clear_range(dn, db->db_blkid, 1, tx);
1245 mutex_exit(&dn->dn_mtx);
1249 dprintf_dbuf(db, "size=%llx\n", (u_longlong_t)db->db.db_size);
1251 ASSERT(db->db.db_size != 0);
1253 /* XXX would be nice to fix up dn_towrite_space[] */
1257 if (dr->dr_parent) {
1258 mutex_enter(&dr->dr_parent->dt.di.dr_mtx);
1259 list_remove(&dr->dr_parent->dt.di.dr_children, dr);
1260 mutex_exit(&dr->dr_parent->dt.di.dr_mtx);
1261 } else if (db->db_level+1 == dn->dn_nlevels) {
1262 ASSERT(db->db_blkptr == NULL || db->db_parent == dn->dn_dbuf);
1263 mutex_enter(&dn->dn_mtx);
1264 list_remove(&dn->dn_dirty_records[txg & TXG_MASK], dr);
1265 mutex_exit(&dn->dn_mtx);
1268 if (db->db_level == 0) {
1269 if (db->db_state != DB_NOFILL) {
1270 dbuf_unoverride(dr);
1272 ASSERT(db->db_buf != NULL);
1273 ASSERT(dr->dt.dl.dr_data != NULL);
1274 if (dr->dt.dl.dr_data != db->db_buf)
1275 VERIFY(arc_buf_remove_ref(dr->dt.dl.dr_data,
1279 ASSERT(db->db_buf != NULL);
1280 ASSERT(list_head(&dr->dt.di.dr_children) == NULL);
1281 mutex_destroy(&dr->dt.di.dr_mtx);
1282 list_destroy(&dr->dt.di.dr_children);
1284 kmem_free(dr, sizeof (dbuf_dirty_record_t));
1286 ASSERT(db->db_dirtycnt > 0);
1287 db->db_dirtycnt -= 1;
1289 if (refcount_remove(&db->db_holds, (void *)(uintptr_t)txg) == 0) {
1290 arc_buf_t *buf = db->db_buf;
1292 ASSERT(db->db_state == DB_NOFILL || arc_released(buf));
1293 dbuf_set_data(db, NULL);
1294 VERIFY(arc_buf_remove_ref(buf, db) == 1);
1299 mutex_exit(&db->db_mtx);
1303 #pragma weak dmu_buf_will_dirty = dbuf_will_dirty
1305 dbuf_will_dirty(dmu_buf_impl_t *db, dmu_tx_t *tx)
1307 int rf = DB_RF_MUST_SUCCEED | DB_RF_NOPREFETCH;
1309 ASSERT(tx->tx_txg != 0);
1310 ASSERT(!refcount_is_zero(&db->db_holds));
1312 if (RW_WRITE_HELD(&db->db_dnode->dn_struct_rwlock))
1313 rf |= DB_RF_HAVESTRUCT;
1314 (void) dbuf_read(db, NULL, rf);
1315 (void) dbuf_dirty(db, tx);
1319 dmu_buf_will_not_fill(dmu_buf_t *db_fake, dmu_tx_t *tx)
1321 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
1323 db->db_state = DB_NOFILL;
1325 dmu_buf_will_fill(db_fake, tx);
1329 dmu_buf_will_fill(dmu_buf_t *db_fake, dmu_tx_t *tx)
1331 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
1333 ASSERT(db->db_blkid != DMU_BONUS_BLKID);
1334 ASSERT(tx->tx_txg != 0);
1335 ASSERT(db->db_level == 0);
1336 ASSERT(!refcount_is_zero(&db->db_holds));
1338 ASSERT(db->db.db_object != DMU_META_DNODE_OBJECT ||
1339 dmu_tx_private_ok(tx));
1342 (void) dbuf_dirty(db, tx);
1345 #pragma weak dmu_buf_fill_done = dbuf_fill_done
1348 dbuf_fill_done(dmu_buf_impl_t *db, dmu_tx_t *tx)
1350 mutex_enter(&db->db_mtx);
1353 if (db->db_state == DB_FILL) {
1354 if (db->db_level == 0 && db->db_freed_in_flight) {
1355 ASSERT(db->db_blkid != DMU_BONUS_BLKID);
1356 /* we were freed while filling */
1357 /* XXX dbuf_undirty? */
1358 bzero(db->db.db_data, db->db.db_size);
1359 db->db_freed_in_flight = FALSE;
1361 db->db_state = DB_CACHED;
1362 cv_broadcast(&db->db_changed);
1364 mutex_exit(&db->db_mtx);
1368 * Directly assign a provided arc buf to a given dbuf if it's not referenced
1369 * by anybody except our caller. Otherwise copy arcbuf's contents to dbuf.
1372 dbuf_assign_arcbuf(dmu_buf_impl_t *db, arc_buf_t *buf, dmu_tx_t *tx)
1374 ASSERT(!refcount_is_zero(&db->db_holds));
1375 ASSERT(db->db_dnode->dn_object != DMU_META_DNODE_OBJECT);
1376 ASSERT(db->db_blkid != DMU_BONUS_BLKID);
1377 ASSERT(db->db_level == 0);
1378 ASSERT(DBUF_GET_BUFC_TYPE(db) == ARC_BUFC_DATA);
1379 ASSERT(buf != NULL);
1380 ASSERT(arc_buf_size(buf) == db->db.db_size);
1381 ASSERT(tx->tx_txg != 0);
1383 arc_return_buf(buf, db);
1384 ASSERT(arc_released(buf));
1386 mutex_enter(&db->db_mtx);
1388 while (db->db_state == DB_READ || db->db_state == DB_FILL)
1389 cv_wait(&db->db_changed, &db->db_mtx);
1391 ASSERT(db->db_state == DB_CACHED || db->db_state == DB_UNCACHED);
1393 if (db->db_state == DB_CACHED &&
1394 refcount_count(&db->db_holds) - 1 > db->db_dirtycnt) {
1395 mutex_exit(&db->db_mtx);
1396 (void) dbuf_dirty(db, tx);
1397 bcopy(buf->b_data, db->db.db_data, db->db.db_size);
1398 VERIFY(arc_buf_remove_ref(buf, db) == 1);
1399 xuio_stat_wbuf_copied();
1403 xuio_stat_wbuf_nocopy();
1404 if (db->db_state == DB_CACHED) {
1405 dbuf_dirty_record_t *dr = db->db_last_dirty;
1407 ASSERT(db->db_buf != NULL);
1408 if (dr != NULL && dr->dr_txg == tx->tx_txg) {
1409 ASSERT(dr->dt.dl.dr_data == db->db_buf);
1410 if (!arc_released(db->db_buf)) {
1411 ASSERT(dr->dt.dl.dr_override_state ==
1413 arc_release(db->db_buf, db);
1415 dr->dt.dl.dr_data = buf;
1416 VERIFY(arc_buf_remove_ref(db->db_buf, db) == 1);
1417 } else if (dr == NULL || dr->dt.dl.dr_data != db->db_buf) {
1418 arc_release(db->db_buf, db);
1419 VERIFY(arc_buf_remove_ref(db->db_buf, db) == 1);
1423 ASSERT(db->db_buf == NULL);
1424 dbuf_set_data(db, buf);
1425 db->db_state = DB_FILL;
1426 mutex_exit(&db->db_mtx);
1427 (void) dbuf_dirty(db, tx);
1428 dbuf_fill_done(db, tx);
1432 * "Clear" the contents of this dbuf. This will mark the dbuf
1433 * EVICTING and clear *most* of its references. Unfortunetely,
1434 * when we are not holding the dn_dbufs_mtx, we can't clear the
1435 * entry in the dn_dbufs list. We have to wait until dbuf_destroy()
1436 * in this case. For callers from the DMU we will usually see:
1437 * dbuf_clear()->arc_buf_evict()->dbuf_do_evict()->dbuf_destroy()
1438 * For the arc callback, we will usually see:
1439 * dbuf_do_evict()->dbuf_clear();dbuf_destroy()
1440 * Sometimes, though, we will get a mix of these two:
1441 * DMU: dbuf_clear()->arc_buf_evict()
1442 * ARC: dbuf_do_evict()->dbuf_destroy()
1445 dbuf_clear(dmu_buf_impl_t *db)
1447 dnode_t *dn = db->db_dnode;
1448 dmu_buf_impl_t *parent = db->db_parent;
1449 dmu_buf_impl_t *dndb = dn->dn_dbuf;
1450 int dbuf_gone = FALSE;
1452 ASSERT(MUTEX_HELD(&db->db_mtx));
1453 ASSERT(refcount_is_zero(&db->db_holds));
1455 dbuf_evict_user(db);
1457 if (db->db_state == DB_CACHED) {
1458 ASSERT(db->db.db_data != NULL);
1459 if (db->db_blkid == DMU_BONUS_BLKID) {
1460 zio_buf_free(db->db.db_data, DN_MAX_BONUSLEN);
1461 arc_space_return(DN_MAX_BONUSLEN, ARC_SPACE_OTHER);
1463 db->db.db_data = NULL;
1464 db->db_state = DB_UNCACHED;
1467 ASSERT(db->db_state == DB_UNCACHED || db->db_state == DB_NOFILL);
1468 ASSERT(db->db_data_pending == NULL);
1470 db->db_state = DB_EVICTING;
1471 db->db_blkptr = NULL;
1473 if (db->db_blkid != DMU_BONUS_BLKID && MUTEX_HELD(&dn->dn_dbufs_mtx)) {
1474 list_remove(&dn->dn_dbufs, db);
1476 db->db_dnode = NULL;
1480 dbuf_gone = arc_buf_evict(db->db_buf);
1483 mutex_exit(&db->db_mtx);
1486 * If this dbuf is referened from an indirect dbuf,
1487 * decrement the ref count on the indirect dbuf.
1489 if (parent && parent != dndb)
1490 dbuf_rele(parent, db);
1494 dbuf_findbp(dnode_t *dn, int level, uint64_t blkid, int fail_sparse,
1495 dmu_buf_impl_t **parentp, blkptr_t **bpp)
1502 ASSERT(blkid != DMU_BONUS_BLKID);
1504 if (blkid == DMU_SPILL_BLKID) {
1505 mutex_enter(&dn->dn_mtx);
1506 if (dn->dn_have_spill &&
1507 (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR))
1508 *bpp = &dn->dn_phys->dn_spill;
1511 dbuf_add_ref(dn->dn_dbuf, NULL);
1512 *parentp = dn->dn_dbuf;
1513 mutex_exit(&dn->dn_mtx);
1517 if (dn->dn_phys->dn_nlevels == 0)
1520 nlevels = dn->dn_phys->dn_nlevels;
1522 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
1524 ASSERT3U(level * epbs, <, 64);
1525 ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock));
1526 if (level >= nlevels ||
1527 (blkid > (dn->dn_phys->dn_maxblkid >> (level * epbs)))) {
1528 /* the buffer has no parent yet */
1530 } else if (level < nlevels-1) {
1531 /* this block is referenced from an indirect block */
1532 int err = dbuf_hold_impl(dn, level+1,
1533 blkid >> epbs, fail_sparse, NULL, parentp);
1536 err = dbuf_read(*parentp, NULL,
1537 (DB_RF_HAVESTRUCT | DB_RF_NOPREFETCH | DB_RF_CANFAIL));
1539 dbuf_rele(*parentp, NULL);
1543 *bpp = ((blkptr_t *)(*parentp)->db.db_data) +
1544 (blkid & ((1ULL << epbs) - 1));
1547 /* the block is referenced from the dnode */
1548 ASSERT3U(level, ==, nlevels-1);
1549 ASSERT(dn->dn_phys->dn_nblkptr == 0 ||
1550 blkid < dn->dn_phys->dn_nblkptr);
1552 dbuf_add_ref(dn->dn_dbuf, NULL);
1553 *parentp = dn->dn_dbuf;
1555 *bpp = &dn->dn_phys->dn_blkptr[blkid];
1560 static dmu_buf_impl_t *
1561 dbuf_create(dnode_t *dn, uint8_t level, uint64_t blkid,
1562 dmu_buf_impl_t *parent, blkptr_t *blkptr)
1564 objset_t *os = dn->dn_objset;
1565 dmu_buf_impl_t *db, *odb;
1567 ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock));
1568 ASSERT(dn->dn_type != DMU_OT_NONE);
1570 db = kmem_cache_alloc(dbuf_cache, KM_SLEEP);
1573 db->db.db_object = dn->dn_object;
1574 db->db_level = level;
1575 db->db_blkid = blkid;
1576 db->db_last_dirty = NULL;
1577 db->db_dirtycnt = 0;
1579 db->db_parent = parent;
1580 db->db_blkptr = blkptr;
1582 db->db_user_ptr = NULL;
1583 db->db_user_data_ptr_ptr = NULL;
1584 db->db_evict_func = NULL;
1585 db->db_immediate_evict = 0;
1586 db->db_freed_in_flight = 0;
1588 if (blkid == DMU_BONUS_BLKID) {
1589 ASSERT3P(parent, ==, dn->dn_dbuf);
1590 db->db.db_size = DN_MAX_BONUSLEN -
1591 (dn->dn_nblkptr-1) * sizeof (blkptr_t);
1592 ASSERT3U(db->db.db_size, >=, dn->dn_bonuslen);
1593 db->db.db_offset = DMU_BONUS_BLKID;
1594 db->db_state = DB_UNCACHED;
1595 /* the bonus dbuf is not placed in the hash table */
1596 arc_space_consume(sizeof (dmu_buf_impl_t), ARC_SPACE_OTHER);
1598 } else if (blkid == DMU_SPILL_BLKID) {
1599 db->db.db_size = (blkptr != NULL) ?
1600 BP_GET_LSIZE(blkptr) : SPA_MINBLOCKSIZE;
1601 db->db.db_offset = 0;
1604 db->db_level ? 1<<dn->dn_indblkshift : dn->dn_datablksz;
1605 db->db.db_size = blocksize;
1606 db->db.db_offset = db->db_blkid * blocksize;
1610 * Hold the dn_dbufs_mtx while we get the new dbuf
1611 * in the hash table *and* added to the dbufs list.
1612 * This prevents a possible deadlock with someone
1613 * trying to look up this dbuf before its added to the
1616 mutex_enter(&dn->dn_dbufs_mtx);
1617 db->db_state = DB_EVICTING;
1618 if ((odb = dbuf_hash_insert(db)) != NULL) {
1619 /* someone else inserted it first */
1620 kmem_cache_free(dbuf_cache, db);
1621 mutex_exit(&dn->dn_dbufs_mtx);
1624 list_insert_head(&dn->dn_dbufs, db);
1625 db->db_state = DB_UNCACHED;
1626 mutex_exit(&dn->dn_dbufs_mtx);
1627 arc_space_consume(sizeof (dmu_buf_impl_t), ARC_SPACE_OTHER);
1629 if (parent && parent != dn->dn_dbuf)
1630 dbuf_add_ref(parent, db);
1632 ASSERT(dn->dn_object == DMU_META_DNODE_OBJECT ||
1633 refcount_count(&dn->dn_holds) > 0);
1634 (void) refcount_add(&dn->dn_holds, db);
1636 dprintf_dbuf(db, "db=%p\n", db);
1642 dbuf_do_evict(void *private)
1644 arc_buf_t *buf = private;
1645 dmu_buf_impl_t *db = buf->b_private;
1647 if (!MUTEX_HELD(&db->db_mtx))
1648 mutex_enter(&db->db_mtx);
1650 ASSERT(refcount_is_zero(&db->db_holds));
1652 if (db->db_state != DB_EVICTING) {
1653 ASSERT(db->db_state == DB_CACHED);
1658 mutex_exit(&db->db_mtx);
1665 dbuf_destroy(dmu_buf_impl_t *db)
1667 ASSERT(refcount_is_zero(&db->db_holds));
1669 if (db->db_blkid != DMU_BONUS_BLKID) {
1671 * If this dbuf is still on the dn_dbufs list,
1672 * remove it from that list.
1675 dnode_t *dn = db->db_dnode;
1677 mutex_enter(&dn->dn_dbufs_mtx);
1678 list_remove(&dn->dn_dbufs, db);
1679 mutex_exit(&dn->dn_dbufs_mtx);
1682 db->db_dnode = NULL;
1684 dbuf_hash_remove(db);
1686 db->db_parent = NULL;
1689 ASSERT(!list_link_active(&db->db_link));
1690 ASSERT(db->db.db_data == NULL);
1691 ASSERT(db->db_hash_next == NULL);
1692 ASSERT(db->db_blkptr == NULL);
1693 ASSERT(db->db_data_pending == NULL);
1695 kmem_cache_free(dbuf_cache, db);
1696 arc_space_return(sizeof (dmu_buf_impl_t), ARC_SPACE_OTHER);
1700 dbuf_prefetch(dnode_t *dn, uint64_t blkid)
1702 dmu_buf_impl_t *db = NULL;
1703 blkptr_t *bp = NULL;
1705 ASSERT(blkid != DMU_BONUS_BLKID);
1706 ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock));
1708 if (dnode_block_freed(dn, blkid))
1711 /* dbuf_find() returns with db_mtx held */
1712 if (db = dbuf_find(dn, 0, blkid)) {
1713 if (refcount_count(&db->db_holds) > 0) {
1715 * This dbuf is active. We assume that it is
1716 * already CACHED, or else about to be either
1719 mutex_exit(&db->db_mtx);
1722 mutex_exit(&db->db_mtx);
1726 if (dbuf_findbp(dn, 0, blkid, TRUE, &db, &bp) == 0) {
1727 if (bp && !BP_IS_HOLE(bp)) {
1728 int priority = dn->dn_type == DMU_OT_DDT_ZAP ?
1729 ZIO_PRIORITY_DDT_PREFETCH : ZIO_PRIORITY_ASYNC_READ;
1731 dsl_dataset_t *ds = dn->dn_objset->os_dsl_dataset;
1732 uint32_t aflags = ARC_NOWAIT | ARC_PREFETCH;
1735 SET_BOOKMARK(&zb, ds ? ds->ds_object : DMU_META_OBJSET,
1736 dn->dn_object, 0, blkid);
1741 pbuf = dn->dn_objset->os_phys_buf;
1743 (void) dsl_read(NULL, dn->dn_objset->os_spa,
1744 bp, pbuf, NULL, NULL, priority,
1745 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE,
1749 dbuf_rele(db, NULL);
1754 * Returns with db_holds incremented, and db_mtx not held.
1755 * Note: dn_struct_rwlock must be held.
1758 dbuf_hold_impl(dnode_t *dn, uint8_t level, uint64_t blkid, int fail_sparse,
1759 void *tag, dmu_buf_impl_t **dbp)
1761 dmu_buf_impl_t *db, *parent = NULL;
1763 ASSERT(blkid != DMU_BONUS_BLKID);
1764 ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock));
1765 ASSERT3U(dn->dn_nlevels, >, level);
1769 /* dbuf_find() returns with db_mtx held */
1770 db = dbuf_find(dn, level, blkid);
1773 blkptr_t *bp = NULL;
1776 ASSERT3P(parent, ==, NULL);
1777 err = dbuf_findbp(dn, level, blkid, fail_sparse, &parent, &bp);
1779 if (err == 0 && bp && BP_IS_HOLE(bp))
1783 dbuf_rele(parent, NULL);
1787 if (err && err != ENOENT)
1789 db = dbuf_create(dn, level, blkid, parent, bp);
1792 if (db->db_buf && refcount_is_zero(&db->db_holds)) {
1793 arc_buf_add_ref(db->db_buf, db);
1794 if (db->db_buf->b_data == NULL) {
1797 dbuf_rele(parent, NULL);
1802 ASSERT3P(db->db.db_data, ==, db->db_buf->b_data);
1805 ASSERT(db->db_buf == NULL || arc_referenced(db->db_buf));
1808 * If this buffer is currently syncing out, and we are are
1809 * still referencing it from db_data, we need to make a copy
1810 * of it in case we decide we want to dirty it again in this txg.
1812 if (db->db_level == 0 && db->db_blkid != DMU_BONUS_BLKID &&
1813 dn->dn_object != DMU_META_DNODE_OBJECT &&
1814 db->db_state == DB_CACHED && db->db_data_pending) {
1815 dbuf_dirty_record_t *dr = db->db_data_pending;
1817 if (dr->dt.dl.dr_data == db->db_buf) {
1818 arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db);
1821 arc_buf_alloc(db->db_dnode->dn_objset->os_spa,
1822 db->db.db_size, db, type));
1823 bcopy(dr->dt.dl.dr_data->b_data, db->db.db_data,
1828 (void) refcount_add(&db->db_holds, tag);
1829 dbuf_update_data(db);
1831 mutex_exit(&db->db_mtx);
1833 /* NOTE: we can't rele the parent until after we drop the db_mtx */
1835 dbuf_rele(parent, NULL);
1837 ASSERT3P(db->db_dnode, ==, dn);
1838 ASSERT3U(db->db_blkid, ==, blkid);
1839 ASSERT3U(db->db_level, ==, level);
1846 dbuf_hold(dnode_t *dn, uint64_t blkid, void *tag)
1849 int err = dbuf_hold_impl(dn, 0, blkid, FALSE, tag, &db);
1850 return (err ? NULL : db);
1854 dbuf_hold_level(dnode_t *dn, int level, uint64_t blkid, void *tag)
1857 int err = dbuf_hold_impl(dn, level, blkid, FALSE, tag, &db);
1858 return (err ? NULL : db);
1862 dbuf_create_bonus(dnode_t *dn)
1864 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
1866 ASSERT(dn->dn_bonus == NULL);
1867 dn->dn_bonus = dbuf_create(dn, 0, DMU_BONUS_BLKID, dn->dn_dbuf, NULL);
1871 dbuf_spill_set_blksz(dmu_buf_t *db_fake, uint64_t blksz, dmu_tx_t *tx)
1873 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
1874 if (db->db_blkid != DMU_SPILL_BLKID)
1877 blksz = SPA_MINBLOCKSIZE;
1878 if (blksz > SPA_MAXBLOCKSIZE)
1879 blksz = SPA_MAXBLOCKSIZE;
1881 blksz = P2ROUNDUP(blksz, SPA_MINBLOCKSIZE);
1883 rw_enter(&db->db_dnode->dn_struct_rwlock, RW_WRITER);
1884 dbuf_new_size(db, blksz, tx);
1885 rw_exit(&db->db_dnode->dn_struct_rwlock);
1891 dbuf_rm_spill(dnode_t *dn, dmu_tx_t *tx)
1893 dbuf_free_range(dn, DMU_SPILL_BLKID, DMU_SPILL_BLKID, tx);
1896 #pragma weak dmu_buf_add_ref = dbuf_add_ref
1898 dbuf_add_ref(dmu_buf_impl_t *db, void *tag)
1900 int64_t holds = refcount_add(&db->db_holds, tag);
1904 #pragma weak dmu_buf_rele = dbuf_rele
1906 dbuf_rele(dmu_buf_impl_t *db, void *tag)
1908 mutex_enter(&db->db_mtx);
1909 dbuf_rele_and_unlock(db, tag);
1913 * dbuf_rele() for an already-locked dbuf. This is necessary to allow
1914 * db_dirtycnt and db_holds to be updated atomically.
1917 dbuf_rele_and_unlock(dmu_buf_impl_t *db, void *tag)
1921 ASSERT(MUTEX_HELD(&db->db_mtx));
1924 holds = refcount_remove(&db->db_holds, tag);
1928 * We can't freeze indirects if there is a possibility that they
1929 * may be modified in the current syncing context.
1931 if (db->db_buf && holds == (db->db_level == 0 ? db->db_dirtycnt : 0))
1932 arc_buf_freeze(db->db_buf);
1934 if (holds == db->db_dirtycnt &&
1935 db->db_level == 0 && db->db_immediate_evict)
1936 dbuf_evict_user(db);
1939 if (db->db_blkid == DMU_BONUS_BLKID) {
1940 mutex_exit(&db->db_mtx);
1941 dnode_rele(db->db_dnode, db);
1942 } else if (db->db_buf == NULL) {
1944 * This is a special case: we never associated this
1945 * dbuf with any data allocated from the ARC.
1947 ASSERT(db->db_state == DB_UNCACHED ||
1948 db->db_state == DB_NOFILL);
1950 } else if (arc_released(db->db_buf)) {
1951 arc_buf_t *buf = db->db_buf;
1953 * This dbuf has anonymous data associated with it.
1955 dbuf_set_data(db, NULL);
1956 VERIFY(arc_buf_remove_ref(buf, db) == 1);
1959 VERIFY(arc_buf_remove_ref(db->db_buf, db) == 0);
1960 if (!DBUF_IS_CACHEABLE(db))
1963 mutex_exit(&db->db_mtx);
1966 mutex_exit(&db->db_mtx);
1970 #pragma weak dmu_buf_refcount = dbuf_refcount
1972 dbuf_refcount(dmu_buf_impl_t *db)
1974 return (refcount_count(&db->db_holds));
1978 dmu_buf_set_user(dmu_buf_t *db_fake, void *user_ptr, void *user_data_ptr_ptr,
1979 dmu_buf_evict_func_t *evict_func)
1981 return (dmu_buf_update_user(db_fake, NULL, user_ptr,
1982 user_data_ptr_ptr, evict_func));
1986 dmu_buf_set_user_ie(dmu_buf_t *db_fake, void *user_ptr, void *user_data_ptr_ptr,
1987 dmu_buf_evict_func_t *evict_func)
1989 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
1991 db->db_immediate_evict = TRUE;
1992 return (dmu_buf_update_user(db_fake, NULL, user_ptr,
1993 user_data_ptr_ptr, evict_func));
1997 dmu_buf_update_user(dmu_buf_t *db_fake, void *old_user_ptr, void *user_ptr,
1998 void *user_data_ptr_ptr, dmu_buf_evict_func_t *evict_func)
2000 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
2001 ASSERT(db->db_level == 0);
2003 ASSERT((user_ptr == NULL) == (evict_func == NULL));
2005 mutex_enter(&db->db_mtx);
2007 if (db->db_user_ptr == old_user_ptr) {
2008 db->db_user_ptr = user_ptr;
2009 db->db_user_data_ptr_ptr = user_data_ptr_ptr;
2010 db->db_evict_func = evict_func;
2012 dbuf_update_data(db);
2014 old_user_ptr = db->db_user_ptr;
2017 mutex_exit(&db->db_mtx);
2018 return (old_user_ptr);
2022 dmu_buf_get_user(dmu_buf_t *db_fake)
2024 dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
2025 ASSERT(!refcount_is_zero(&db->db_holds));
2027 return (db->db_user_ptr);
2031 dmu_buf_freeable(dmu_buf_t *dbuf)
2033 boolean_t res = B_FALSE;
2034 dmu_buf_impl_t *db = (dmu_buf_impl_t *)dbuf;
2037 res = dsl_dataset_block_freeable(db->db_objset->os_dsl_dataset,
2038 db->db_blkptr, db->db_blkptr->blk_birth);
2044 dbuf_check_blkptr(dnode_t *dn, dmu_buf_impl_t *db)
2046 /* ASSERT(dmu_tx_is_syncing(tx) */
2047 ASSERT(MUTEX_HELD(&db->db_mtx));
2049 if (db->db_blkptr != NULL)
2052 if (db->db_blkid == DMU_SPILL_BLKID) {
2053 db->db_blkptr = &dn->dn_phys->dn_spill;
2054 BP_ZERO(db->db_blkptr);
2057 if (db->db_level == dn->dn_phys->dn_nlevels-1) {
2059 * This buffer was allocated at a time when there was
2060 * no available blkptrs from the dnode, or it was
2061 * inappropriate to hook it in (i.e., nlevels mis-match).
2063 ASSERT(db->db_blkid < dn->dn_phys->dn_nblkptr);
2064 ASSERT(db->db_parent == NULL);
2065 db->db_parent = dn->dn_dbuf;
2066 db->db_blkptr = &dn->dn_phys->dn_blkptr[db->db_blkid];
2069 dmu_buf_impl_t *parent = db->db_parent;
2070 int epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
2072 ASSERT(dn->dn_phys->dn_nlevels > 1);
2073 if (parent == NULL) {
2074 mutex_exit(&db->db_mtx);
2075 rw_enter(&dn->dn_struct_rwlock, RW_READER);
2076 (void) dbuf_hold_impl(dn, db->db_level+1,
2077 db->db_blkid >> epbs, FALSE, db, &parent);
2078 rw_exit(&dn->dn_struct_rwlock);
2079 mutex_enter(&db->db_mtx);
2080 db->db_parent = parent;
2082 db->db_blkptr = (blkptr_t *)parent->db.db_data +
2083 (db->db_blkid & ((1ULL << epbs) - 1));
2089 dbuf_sync_indirect(dbuf_dirty_record_t *dr, dmu_tx_t *tx)
2091 dmu_buf_impl_t *db = dr->dr_dbuf;
2092 dnode_t *dn = db->db_dnode;
2095 ASSERT(dmu_tx_is_syncing(tx));
2097 dprintf_dbuf_bp(db, db->db_blkptr, "blkptr=%p", db->db_blkptr);
2099 mutex_enter(&db->db_mtx);
2101 ASSERT(db->db_level > 0);
2104 if (db->db_buf == NULL) {
2105 mutex_exit(&db->db_mtx);
2106 (void) dbuf_read(db, NULL, DB_RF_MUST_SUCCEED);
2107 mutex_enter(&db->db_mtx);
2109 ASSERT3U(db->db_state, ==, DB_CACHED);
2110 ASSERT3U(db->db.db_size, ==, 1<<dn->dn_phys->dn_indblkshift);
2111 ASSERT(db->db_buf != NULL);
2113 dbuf_check_blkptr(dn, db);
2115 db->db_data_pending = dr;
2117 mutex_exit(&db->db_mtx);
2118 dbuf_write(dr, db->db_buf, tx);
2121 mutex_enter(&dr->dt.di.dr_mtx);
2122 dbuf_sync_list(&dr->dt.di.dr_children, tx);
2123 ASSERT(list_head(&dr->dt.di.dr_children) == NULL);
2124 mutex_exit(&dr->dt.di.dr_mtx);
2129 dbuf_sync_leaf(dbuf_dirty_record_t *dr, dmu_tx_t *tx)
2131 arc_buf_t **datap = &dr->dt.dl.dr_data;
2132 dmu_buf_impl_t *db = dr->dr_dbuf;
2133 dnode_t *dn = db->db_dnode;
2134 objset_t *os = dn->dn_objset;
2135 uint64_t txg = tx->tx_txg;
2137 ASSERT(dmu_tx_is_syncing(tx));
2139 dprintf_dbuf_bp(db, db->db_blkptr, "blkptr=%p", db->db_blkptr);
2141 mutex_enter(&db->db_mtx);
2143 * To be synced, we must be dirtied. But we
2144 * might have been freed after the dirty.
2146 if (db->db_state == DB_UNCACHED) {
2147 /* This buffer has been freed since it was dirtied */
2148 ASSERT(db->db.db_data == NULL);
2149 } else if (db->db_state == DB_FILL) {
2150 /* This buffer was freed and is now being re-filled */
2151 ASSERT(db->db.db_data != dr->dt.dl.dr_data);
2153 ASSERT(db->db_state == DB_CACHED || db->db_state == DB_NOFILL);
2157 if (db->db_blkid == DMU_SPILL_BLKID) {
2158 mutex_enter(&dn->dn_mtx);
2159 dn->dn_phys->dn_flags |= DNODE_FLAG_SPILL_BLKPTR;
2160 mutex_exit(&dn->dn_mtx);
2164 * If this is a bonus buffer, simply copy the bonus data into the
2165 * dnode. It will be written out when the dnode is synced (and it
2166 * will be synced, since it must have been dirty for dbuf_sync to
2169 if (db->db_blkid == DMU_BONUS_BLKID) {
2170 dbuf_dirty_record_t **drp;
2172 ASSERT(*datap != NULL);
2173 ASSERT3U(db->db_level, ==, 0);
2174 ASSERT3U(dn->dn_phys->dn_bonuslen, <=, DN_MAX_BONUSLEN);
2175 bcopy(*datap, DN_BONUS(dn->dn_phys), dn->dn_phys->dn_bonuslen);
2176 if (*datap != db->db.db_data) {
2177 zio_buf_free(*datap, DN_MAX_BONUSLEN);
2178 arc_space_return(DN_MAX_BONUSLEN, ARC_SPACE_OTHER);
2180 db->db_data_pending = NULL;
2181 drp = &db->db_last_dirty;
2183 drp = &(*drp)->dr_next;
2184 ASSERT(dr->dr_next == NULL);
2185 ASSERT(dr->dr_dbuf == db);
2187 kmem_free(dr, sizeof (dbuf_dirty_record_t));
2188 ASSERT(db->db_dirtycnt > 0);
2189 db->db_dirtycnt -= 1;
2190 dbuf_rele_and_unlock(db, (void *)(uintptr_t)txg);
2195 * This function may have dropped the db_mtx lock allowing a dmu_sync
2196 * operation to sneak in. As a result, we need to ensure that we
2197 * don't check the dr_override_state until we have returned from
2198 * dbuf_check_blkptr.
2200 dbuf_check_blkptr(dn, db);
2203 * If this buffer is in the middle of an immdiate write,
2204 * wait for the synchronous IO to complete.
2206 while (dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC) {
2207 ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT);
2208 cv_wait(&db->db_changed, &db->db_mtx);
2209 ASSERT(dr->dt.dl.dr_override_state != DR_NOT_OVERRIDDEN);
2212 if (db->db_state != DB_NOFILL &&
2213 dn->dn_object != DMU_META_DNODE_OBJECT &&
2214 refcount_count(&db->db_holds) > 1 &&
2215 dr->dt.dl.dr_override_state != DR_OVERRIDDEN &&
2216 *datap == db->db_buf) {
2218 * If this buffer is currently "in use" (i.e., there
2219 * are active holds and db_data still references it),
2220 * then make a copy before we start the write so that
2221 * any modifications from the open txg will not leak
2224 * NOTE: this copy does not need to be made for
2225 * objects only modified in the syncing context (e.g.
2226 * DNONE_DNODE blocks).
2228 int blksz = arc_buf_size(*datap);
2229 arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db);
2230 *datap = arc_buf_alloc(os->os_spa, blksz, db, type);
2231 bcopy(db->db.db_data, (*datap)->b_data, blksz);
2233 db->db_data_pending = dr;
2235 mutex_exit(&db->db_mtx);
2237 dbuf_write(dr, *datap, tx);
2239 ASSERT(!list_link_active(&dr->dr_dirty_node));
2240 if (dn->dn_object == DMU_META_DNODE_OBJECT)
2241 list_insert_tail(&dn->dn_dirty_records[txg&TXG_MASK], dr);
2243 zio_nowait(dr->dr_zio);
2247 dbuf_sync_list(list_t *list, dmu_tx_t *tx)
2249 dbuf_dirty_record_t *dr;
2251 while (dr = list_head(list)) {
2252 if (dr->dr_zio != NULL) {
2254 * If we find an already initialized zio then we
2255 * are processing the meta-dnode, and we have finished.
2256 * The dbufs for all dnodes are put back on the list
2257 * during processing, so that we can zio_wait()
2258 * these IOs after initiating all child IOs.
2260 ASSERT3U(dr->dr_dbuf->db.db_object, ==,
2261 DMU_META_DNODE_OBJECT);
2264 list_remove(list, dr);
2265 if (dr->dr_dbuf->db_level > 0)
2266 dbuf_sync_indirect(dr, tx);
2268 dbuf_sync_leaf(dr, tx);
2274 dbuf_write_ready(zio_t *zio, arc_buf_t *buf, void *vdb)
2276 dmu_buf_impl_t *db = vdb;
2277 blkptr_t *bp = zio->io_bp;
2278 blkptr_t *bp_orig = &zio->io_bp_orig;
2279 dnode_t *dn = db->db_dnode;
2280 spa_t *spa = zio->io_spa;
2285 ASSERT(db->db_blkptr == bp);
2287 delta = bp_get_dsize_sync(spa, bp) - bp_get_dsize_sync(spa, bp_orig);
2288 dnode_diduse_space(dn, delta - zio->io_prev_space_delta);
2289 zio->io_prev_space_delta = delta;
2291 if (BP_IS_HOLE(bp)) {
2292 ASSERT(bp->blk_fill == 0);
2296 ASSERT((db->db_blkid != DMU_SPILL_BLKID &&
2297 BP_GET_TYPE(bp) == dn->dn_type) ||
2298 (db->db_blkid == DMU_SPILL_BLKID &&
2299 BP_GET_TYPE(bp) == dn->dn_bonustype));
2300 ASSERT(BP_GET_LEVEL(bp) == db->db_level);
2302 mutex_enter(&db->db_mtx);
2305 if (db->db_blkid == DMU_SPILL_BLKID) {
2306 dnode_t *dn = db->db_dnode;
2307 ASSERT(dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR);
2308 ASSERT(!(BP_IS_HOLE(db->db_blkptr)) &&
2309 db->db_blkptr == &dn->dn_phys->dn_spill);
2313 if (db->db_level == 0) {
2314 mutex_enter(&dn->dn_mtx);
2315 if (db->db_blkid > dn->dn_phys->dn_maxblkid &&
2316 db->db_blkid != DMU_SPILL_BLKID)
2317 dn->dn_phys->dn_maxblkid = db->db_blkid;
2318 mutex_exit(&dn->dn_mtx);
2320 if (dn->dn_type == DMU_OT_DNODE) {
2321 dnode_phys_t *dnp = db->db.db_data;
2322 for (i = db->db.db_size >> DNODE_SHIFT; i > 0;
2324 if (dnp->dn_type != DMU_OT_NONE)
2331 blkptr_t *ibp = db->db.db_data;
2332 ASSERT3U(db->db.db_size, ==, 1<<dn->dn_phys->dn_indblkshift);
2333 for (i = db->db.db_size >> SPA_BLKPTRSHIFT; i > 0; i--, ibp++) {
2334 if (BP_IS_HOLE(ibp))
2336 fill += ibp->blk_fill;
2340 bp->blk_fill = fill;
2342 mutex_exit(&db->db_mtx);
2347 dbuf_write_done(zio_t *zio, arc_buf_t *buf, void *vdb)
2349 dmu_buf_impl_t *db = vdb;
2350 blkptr_t *bp = zio->io_bp;
2351 blkptr_t *bp_orig = &zio->io_bp_orig;
2352 dnode_t *dn = db->db_dnode;
2353 objset_t *os = dn->dn_objset;
2354 uint64_t txg = zio->io_txg;
2355 dbuf_dirty_record_t **drp, *dr;
2357 ASSERT3U(zio->io_error, ==, 0);
2358 ASSERT(db->db_blkptr == bp);
2360 if (zio->io_flags & ZIO_FLAG_IO_REWRITE) {
2361 ASSERT(BP_EQUAL(bp, bp_orig));
2363 dsl_dataset_t *ds = os->os_dsl_dataset;
2364 dmu_tx_t *tx = os->os_synctx;
2366 (void) dsl_dataset_block_kill(ds, bp_orig, tx, B_TRUE);
2367 dsl_dataset_block_born(ds, bp, tx);
2370 mutex_enter(&db->db_mtx);
2374 drp = &db->db_last_dirty;
2375 while ((dr = *drp) != db->db_data_pending)
2377 ASSERT(!list_link_active(&dr->dr_dirty_node));
2378 ASSERT(dr->dr_txg == txg);
2379 ASSERT(dr->dr_dbuf == db);
2380 ASSERT(dr->dr_next == NULL);
2384 if (db->db_blkid == DMU_SPILL_BLKID) {
2385 dnode_t *dn = db->db_dnode;
2386 ASSERT(dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR);
2387 ASSERT(!(BP_IS_HOLE(db->db_blkptr)) &&
2388 db->db_blkptr == &dn->dn_phys->dn_spill);
2392 if (db->db_level == 0) {
2393 ASSERT(db->db_blkid != DMU_BONUS_BLKID);
2394 ASSERT(dr->dt.dl.dr_override_state == DR_NOT_OVERRIDDEN);
2395 if (db->db_state != DB_NOFILL) {
2396 if (dr->dt.dl.dr_data != db->db_buf)
2397 VERIFY(arc_buf_remove_ref(dr->dt.dl.dr_data,
2399 else if (!arc_released(db->db_buf))
2400 arc_set_callback(db->db_buf, dbuf_do_evict, db);
2403 ASSERT(list_head(&dr->dt.di.dr_children) == NULL);
2404 ASSERT3U(db->db.db_size, ==, 1<<dn->dn_phys->dn_indblkshift);
2405 if (!BP_IS_HOLE(db->db_blkptr)) {
2407 dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
2408 ASSERT3U(BP_GET_LSIZE(db->db_blkptr), ==,
2410 ASSERT3U(dn->dn_phys->dn_maxblkid
2411 >> (db->db_level * epbs), >=, db->db_blkid);
2412 arc_set_callback(db->db_buf, dbuf_do_evict, db);
2414 mutex_destroy(&dr->dt.di.dr_mtx);
2415 list_destroy(&dr->dt.di.dr_children);
2417 kmem_free(dr, sizeof (dbuf_dirty_record_t));
2419 cv_broadcast(&db->db_changed);
2420 ASSERT(db->db_dirtycnt > 0);
2421 db->db_dirtycnt -= 1;
2422 db->db_data_pending = NULL;
2423 dbuf_rele_and_unlock(db, (void *)(uintptr_t)txg);
2427 dbuf_write_nofill_ready(zio_t *zio)
2429 dbuf_write_ready(zio, NULL, zio->io_private);
2433 dbuf_write_nofill_done(zio_t *zio)
2435 dbuf_write_done(zio, NULL, zio->io_private);
2439 dbuf_write_override_ready(zio_t *zio)
2441 dbuf_dirty_record_t *dr = zio->io_private;
2442 dmu_buf_impl_t *db = dr->dr_dbuf;
2444 dbuf_write_ready(zio, NULL, db);
2448 dbuf_write_override_done(zio_t *zio)
2450 dbuf_dirty_record_t *dr = zio->io_private;
2451 dmu_buf_impl_t *db = dr->dr_dbuf;
2452 blkptr_t *obp = &dr->dt.dl.dr_overridden_by;
2454 mutex_enter(&db->db_mtx);
2455 if (!BP_EQUAL(zio->io_bp, obp)) {
2456 if (!BP_IS_HOLE(obp))
2457 dsl_free(spa_get_dsl(zio->io_spa), zio->io_txg, obp);
2458 arc_release(dr->dt.dl.dr_data, db);
2460 mutex_exit(&db->db_mtx);
2462 dbuf_write_done(zio, NULL, db);
2466 dbuf_write(dbuf_dirty_record_t *dr, arc_buf_t *data, dmu_tx_t *tx)
2468 dmu_buf_impl_t *db = dr->dr_dbuf;
2469 dnode_t *dn = db->db_dnode;
2470 objset_t *os = dn->dn_objset;
2471 dmu_buf_impl_t *parent = db->db_parent;
2472 uint64_t txg = tx->tx_txg;
2478 if (db->db_state != DB_NOFILL) {
2479 if (db->db_level > 0 || dn->dn_type == DMU_OT_DNODE) {
2481 * Private object buffers are released here rather
2482 * than in dbuf_dirty() since they are only modified
2483 * in the syncing context and we don't want the
2484 * overhead of making multiple copies of the data.
2486 if (BP_IS_HOLE(db->db_blkptr)) {
2489 dbuf_release_bp(db);
2494 if (parent != dn->dn_dbuf) {
2495 ASSERT(parent && parent->db_data_pending);
2496 ASSERT(db->db_level == parent->db_level-1);
2497 ASSERT(arc_released(parent->db_buf));
2498 zio = parent->db_data_pending->dr_zio;
2500 ASSERT((db->db_level == dn->dn_phys->dn_nlevels-1 &&
2501 db->db_blkid != DMU_SPILL_BLKID) ||
2502 (db->db_blkid == DMU_SPILL_BLKID && db->db_level == 0));
2503 if (db->db_blkid != DMU_SPILL_BLKID)
2504 ASSERT3P(db->db_blkptr, ==,
2505 &dn->dn_phys->dn_blkptr[db->db_blkid]);
2509 ASSERT(db->db_level == 0 || data == db->db_buf);
2510 ASSERT3U(db->db_blkptr->blk_birth, <=, txg);
2513 SET_BOOKMARK(&zb, os->os_dsl_dataset ?
2514 os->os_dsl_dataset->ds_object : DMU_META_OBJSET,
2515 db->db.db_object, db->db_level, db->db_blkid);
2517 if (db->db_blkid == DMU_SPILL_BLKID)
2519 wp_flag |= (db->db_state == DB_NOFILL) ? WP_NOFILL : 0;
2521 dmu_write_policy(os, dn, db->db_level, wp_flag, &zp);
2523 if (db->db_level == 0 && dr->dt.dl.dr_override_state == DR_OVERRIDDEN) {
2524 ASSERT(db->db_state != DB_NOFILL);
2525 dr->dr_zio = zio_write(zio, os->os_spa, txg,
2526 db->db_blkptr, data->b_data, arc_buf_size(data), &zp,
2527 dbuf_write_override_ready, dbuf_write_override_done, dr,
2528 ZIO_PRIORITY_ASYNC_WRITE, ZIO_FLAG_MUSTSUCCEED, &zb);
2529 mutex_enter(&db->db_mtx);
2530 dr->dt.dl.dr_override_state = DR_NOT_OVERRIDDEN;
2531 zio_write_override(dr->dr_zio, &dr->dt.dl.dr_overridden_by,
2532 dr->dt.dl.dr_copies);
2533 mutex_exit(&db->db_mtx);
2534 } else if (db->db_state == DB_NOFILL) {
2535 ASSERT(zp.zp_checksum == ZIO_CHECKSUM_OFF);
2536 dr->dr_zio = zio_write(zio, os->os_spa, txg,
2537 db->db_blkptr, NULL, db->db.db_size, &zp,
2538 dbuf_write_nofill_ready, dbuf_write_nofill_done, db,
2539 ZIO_PRIORITY_ASYNC_WRITE,
2540 ZIO_FLAG_MUSTSUCCEED | ZIO_FLAG_NODATA, &zb);
2542 ASSERT(arc_released(data));
2543 dr->dr_zio = arc_write(zio, os->os_spa, txg,
2544 db->db_blkptr, data, DBUF_IS_L2CACHEABLE(db), &zp,
2545 dbuf_write_ready, dbuf_write_done, db,
2546 ZIO_PRIORITY_ASYNC_WRITE, ZIO_FLAG_MUSTSUCCEED, &zb);