xref: /illumos-gate/usr/src/uts/common/fs/zfs/dbuf.c (revision 0f6d88ad)
1fa9e4066Sahrens /*
2fa9e4066Sahrens  * CDDL HEADER START
3fa9e4066Sahrens  *
4fa9e4066Sahrens  * The contents of this file are subject to the terms of the
5f65e61c0Sahrens  * Common Development and Distribution License (the "License").
6f65e61c0Sahrens  * You may not use this file except in compliance with the License.
7fa9e4066Sahrens  *
8fa9e4066Sahrens  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9fa9e4066Sahrens  * or http://www.opensolaris.org/os/licensing.
10fa9e4066Sahrens  * See the License for the specific language governing permissions
11fa9e4066Sahrens  * and limitations under the License.
12fa9e4066Sahrens  *
13fa9e4066Sahrens  * When distributing Covered Code, include this CDDL HEADER in each
14fa9e4066Sahrens  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15fa9e4066Sahrens  * If applicable, add the following below this CDDL HEADER, with the
16fa9e4066Sahrens  * fields enclosed by brackets "[]" replaced with your own identifying
17fa9e4066Sahrens  * information: Portions Copyright [yyyy] [name of copyright owner]
18fa9e4066Sahrens  *
19fa9e4066Sahrens  * CDDL HEADER END
20fa9e4066Sahrens  */
21fa9e4066Sahrens /*
2206e0070dSMark Shellenbaum  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
233f2366c2SGordon Ross  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
24bf16b11eSMatthew Ahrens  * Copyright (c) 2012, 2014 by Delphix. All rights reserved.
25aad02571SSaso Kiselkov  * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
26810e43b2SBill Pijewski  * Copyright (c) 2013, Joyent, Inc. All rights reserved.
27fa9e4066Sahrens  */
28fa9e4066Sahrens 
29fa9e4066Sahrens #include <sys/zfs_context.h>
30fa9e4066Sahrens #include <sys/dmu.h>
312f3d8780SMatthew Ahrens #include <sys/dmu_send.h>
32fa9e4066Sahrens #include <sys/dmu_impl.h>
33fa9e4066Sahrens #include <sys/dbuf.h>
34fa9e4066Sahrens #include <sys/dmu_objset.h>
35fa9e4066Sahrens #include <sys/dsl_dataset.h>
36fa9e4066Sahrens #include <sys/dsl_dir.h>
37fa9e4066Sahrens #include <sys/dmu_tx.h>
38fa9e4066Sahrens #include <sys/spa.h>
39fa9e4066Sahrens #include <sys/zio.h>
40fa9e4066Sahrens #include <sys/dmu_zfetch.h>
410a586ceaSMark Shellenbaum #include <sys/sa.h>
420a586ceaSMark Shellenbaum #include <sys/sa_impl.h>
435d7b4d43SMatthew Ahrens #include <sys/zfeature.h>
445d7b4d43SMatthew Ahrens #include <sys/blkptr.h>
45bf16b11eSMatthew Ahrens #include <sys/range_tree.h>
46fa9e4066Sahrens 
47713d6c20SMatthew Ahrens /*
48713d6c20SMatthew Ahrens  * Number of times that zfs_free_range() took the slow path while doing
49713d6c20SMatthew Ahrens  * a zfs receive.  A nonzero value indicates a potential performance problem.
50713d6c20SMatthew Ahrens  */
51713d6c20SMatthew Ahrens uint64_t zfs_free_range_recv_miss;
52713d6c20SMatthew Ahrens 
53fa9e4066Sahrens static void dbuf_destroy(dmu_buf_impl_t *db);
543b2aab18SMatthew Ahrens static boolean_t dbuf_undirty(dmu_buf_impl_t *db, dmu_tx_t *tx);
55088f3894Sahrens static void dbuf_write(dbuf_dirty_record_t *dr, arc_buf_t *data, dmu_tx_t *tx);
56fa9e4066Sahrens 
57fa9e4066Sahrens /*
58fa9e4066Sahrens  * Global data structures and functions for the dbuf cache.
59fa9e4066Sahrens  */
60fa9e4066Sahrens static kmem_cache_t *dbuf_cache;
61fa9e4066Sahrens 
62fa9e4066Sahrens /* ARGSUSED */
63fa9e4066Sahrens static int
64fa9e4066Sahrens dbuf_cons(void *vdb, void *unused, int kmflag)
65fa9e4066Sahrens {
66fa9e4066Sahrens 	dmu_buf_impl_t *db = vdb;
67fa9e4066Sahrens 	bzero(db, sizeof (dmu_buf_impl_t));
68fa9e4066Sahrens 
69fa9e4066Sahrens 	mutex_init(&db->db_mtx, NULL, MUTEX_DEFAULT, NULL);
70fa9e4066Sahrens 	cv_init(&db->db_changed, NULL, CV_DEFAULT, NULL);
71fa9e4066Sahrens 	refcount_create(&db->db_holds);
72*0f6d88adSAlex Reece 
73*0f6d88adSAlex Reece 	db->db_creation = gethrtime();
74*0f6d88adSAlex Reece 
75fa9e4066Sahrens 	return (0);
76fa9e4066Sahrens }
77fa9e4066Sahrens 
78fa9e4066Sahrens /* ARGSUSED */
79fa9e4066Sahrens static void
80fa9e4066Sahrens dbuf_dest(void *vdb, void *unused)
81fa9e4066Sahrens {
82fa9e4066Sahrens 	dmu_buf_impl_t *db = vdb;
83fa9e4066Sahrens 	mutex_destroy(&db->db_mtx);
84fa9e4066Sahrens 	cv_destroy(&db->db_changed);
85fa9e4066Sahrens 	refcount_destroy(&db->db_holds);
86fa9e4066Sahrens }
87fa9e4066Sahrens 
88fa9e4066Sahrens /*
89fa9e4066Sahrens  * dbuf hash table routines
90fa9e4066Sahrens  */
91fa9e4066Sahrens static dbuf_hash_table_t dbuf_hash_table;
92fa9e4066Sahrens 
93fa9e4066Sahrens static uint64_t dbuf_hash_count;
94fa9e4066Sahrens 
95fa9e4066Sahrens static uint64_t
96fa9e4066Sahrens dbuf_hash(void *os, uint64_t obj, uint8_t lvl, uint64_t blkid)
97fa9e4066Sahrens {
98fa9e4066Sahrens 	uintptr_t osv = (uintptr_t)os;
99fa9e4066Sahrens 	uint64_t crc = -1ULL;
100fa9e4066Sahrens 
101fa9e4066Sahrens 	ASSERT(zfs_crc64_table[128] == ZFS_CRC64_POLY);
102fa9e4066Sahrens 	crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (lvl)) & 0xFF];
103fa9e4066Sahrens 	crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (osv >> 6)) & 0xFF];
104fa9e4066Sahrens 	crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (obj >> 0)) & 0xFF];
105fa9e4066Sahrens 	crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (obj >> 8)) & 0xFF];
106fa9e4066Sahrens 	crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (blkid >> 0)) & 0xFF];
107fa9e4066Sahrens 	crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (blkid >> 8)) & 0xFF];
108fa9e4066Sahrens 
109fa9e4066Sahrens 	crc ^= (osv>>14) ^ (obj>>16) ^ (blkid>>16);
110fa9e4066Sahrens 
111fa9e4066Sahrens 	return (crc);
112fa9e4066Sahrens }
113fa9e4066Sahrens 
114fa9e4066Sahrens #define	DBUF_HASH(os, obj, level, blkid) dbuf_hash(os, obj, level, blkid);
115fa9e4066Sahrens 
116fa9e4066Sahrens #define	DBUF_EQUAL(dbuf, os, obj, level, blkid)		\
117fa9e4066Sahrens 	((dbuf)->db.db_object == (obj) &&		\
118fa9e4066Sahrens 	(dbuf)->db_objset == (os) &&			\
119fa9e4066Sahrens 	(dbuf)->db_level == (level) &&			\
120fa9e4066Sahrens 	(dbuf)->db_blkid == (blkid))
121fa9e4066Sahrens 
122fa9e4066Sahrens dmu_buf_impl_t *
123fa9e4066Sahrens dbuf_find(dnode_t *dn, uint8_t level, uint64_t blkid)
124fa9e4066Sahrens {
125fa9e4066Sahrens 	dbuf_hash_table_t *h = &dbuf_hash_table;
126503ad85cSMatthew Ahrens 	objset_t *os = dn->dn_objset;
127fa9e4066Sahrens 	uint64_t obj = dn->dn_object;
128fa9e4066Sahrens 	uint64_t hv = DBUF_HASH(os, obj, level, blkid);
129fa9e4066Sahrens 	uint64_t idx = hv & h->hash_table_mask;
130fa9e4066Sahrens 	dmu_buf_impl_t *db;
131fa9e4066Sahrens 
132fa9e4066Sahrens 	mutex_enter(DBUF_HASH_MUTEX(h, idx));
133fa9e4066Sahrens 	for (db = h->hash_table[idx]; db != NULL; db = db->db_hash_next) {
134fa9e4066Sahrens 		if (DBUF_EQUAL(db, os, obj, level, blkid)) {
135fa9e4066Sahrens 			mutex_enter(&db->db_mtx);
136ea8dc4b6Seschrock 			if (db->db_state != DB_EVICTING) {
137fa9e4066Sahrens 				mutex_exit(DBUF_HASH_MUTEX(h, idx));
138fa9e4066Sahrens 				return (db);
139fa9e4066Sahrens 			}
140fa9e4066Sahrens 			mutex_exit(&db->db_mtx);
141fa9e4066Sahrens 		}
142fa9e4066Sahrens 	}
143fa9e4066Sahrens 	mutex_exit(DBUF_HASH_MUTEX(h, idx));
144fa9e4066Sahrens 	return (NULL);
145fa9e4066Sahrens }
146fa9e4066Sahrens 
147fa9e4066Sahrens /*
148fa9e4066Sahrens  * Insert an entry into the hash table.  If there is already an element
149fa9e4066Sahrens  * equal to elem in the hash table, then the already existing element
150fa9e4066Sahrens  * will be returned and the new element will not be inserted.
151fa9e4066Sahrens  * Otherwise returns NULL.
152fa9e4066Sahrens  */
153fa9e4066Sahrens static dmu_buf_impl_t *
154fa9e4066Sahrens dbuf_hash_insert(dmu_buf_impl_t *db)
155fa9e4066Sahrens {
156fa9e4066Sahrens 	dbuf_hash_table_t *h = &dbuf_hash_table;
157503ad85cSMatthew Ahrens 	objset_t *os = db->db_objset;
158fa9e4066Sahrens 	uint64_t obj = db->db.db_object;
159fa9e4066Sahrens 	int level = db->db_level;
160fa9e4066Sahrens 	uint64_t blkid = db->db_blkid;
161fa9e4066Sahrens 	uint64_t hv = DBUF_HASH(os, obj, level, blkid);
162fa9e4066Sahrens 	uint64_t idx = hv & h->hash_table_mask;
163fa9e4066Sahrens 	dmu_buf_impl_t *dbf;
164fa9e4066Sahrens 
165fa9e4066Sahrens 	mutex_enter(DBUF_HASH_MUTEX(h, idx));
166fa9e4066Sahrens 	for (dbf = h->hash_table[idx]; dbf != NULL; dbf = dbf->db_hash_next) {
167fa9e4066Sahrens 		if (DBUF_EQUAL(dbf, os, obj, level, blkid)) {
168fa9e4066Sahrens 			mutex_enter(&dbf->db_mtx);
169ea8dc4b6Seschrock 			if (dbf->db_state != DB_EVICTING) {
170fa9e4066Sahrens 				mutex_exit(DBUF_HASH_MUTEX(h, idx));
171fa9e4066Sahrens 				return (dbf);
172fa9e4066Sahrens 			}
173fa9e4066Sahrens 			mutex_exit(&dbf->db_mtx);
174fa9e4066Sahrens 		}
175fa9e4066Sahrens 	}
176fa9e4066Sahrens 
177fa9e4066Sahrens 	mutex_enter(&db->db_mtx);
178fa9e4066Sahrens 	db->db_hash_next = h->hash_table[idx];
179fa9e4066Sahrens 	h->hash_table[idx] = db;
180fa9e4066Sahrens 	mutex_exit(DBUF_HASH_MUTEX(h, idx));
181fa9e4066Sahrens 	atomic_add_64(&dbuf_hash_count, 1);
182fa9e4066Sahrens 
183fa9e4066Sahrens 	return (NULL);
184fa9e4066Sahrens }
185fa9e4066Sahrens 
186fa9e4066Sahrens /*
187bbfa8ea8SMatthew Ahrens  * Remove an entry from the hash table.  It must be in the EVICTING state.
188fa9e4066Sahrens  */
189fa9e4066Sahrens static void
190fa9e4066Sahrens dbuf_hash_remove(dmu_buf_impl_t *db)
191fa9e4066Sahrens {
192fa9e4066Sahrens 	dbuf_hash_table_t *h = &dbuf_hash_table;
193fa9e4066Sahrens 	uint64_t hv = DBUF_HASH(db->db_objset, db->db.db_object,
194fa9e4066Sahrens 	    db->db_level, db->db_blkid);
195fa9e4066Sahrens 	uint64_t idx = hv & h->hash_table_mask;
196fa9e4066Sahrens 	dmu_buf_impl_t *dbf, **dbp;
197fa9e4066Sahrens 
198fa9e4066Sahrens 	/*
199bbfa8ea8SMatthew Ahrens 	 * We musn't hold db_mtx to maintain lock ordering:
200fa9e4066Sahrens 	 * DBUF_HASH_MUTEX > db_mtx.
201fa9e4066Sahrens 	 */
202fa9e4066Sahrens 	ASSERT(refcount_is_zero(&db->db_holds));
203ea8dc4b6Seschrock 	ASSERT(db->db_state == DB_EVICTING);
204fa9e4066Sahrens 	ASSERT(!MUTEX_HELD(&db->db_mtx));
205fa9e4066Sahrens 
206fa9e4066Sahrens 	mutex_enter(DBUF_HASH_MUTEX(h, idx));
207fa9e4066Sahrens 	dbp = &h->hash_table[idx];
208fa9e4066Sahrens 	while ((dbf = *dbp) != db) {
209fa9e4066Sahrens 		dbp = &dbf->db_hash_next;
210fa9e4066Sahrens 		ASSERT(dbf != NULL);
211fa9e4066Sahrens 	}
212fa9e4066Sahrens 	*dbp = db->db_hash_next;
213fa9e4066Sahrens 	db->db_hash_next = NULL;
214fa9e4066Sahrens 	mutex_exit(DBUF_HASH_MUTEX(h, idx));
215fa9e4066Sahrens 	atomic_add_64(&dbuf_hash_count, -1);
216fa9e4066Sahrens }
217fa9e4066Sahrens 
218ea8dc4b6Seschrock static arc_evict_func_t dbuf_do_evict;
219fa9e4066Sahrens 
220fa9e4066Sahrens static void
221fa9e4066Sahrens dbuf_evict_user(dmu_buf_impl_t *db)
222fa9e4066Sahrens {
223fa9e4066Sahrens 	ASSERT(MUTEX_HELD(&db->db_mtx));
224fa9e4066Sahrens 
225c717a561Smaybee 	if (db->db_level != 0 || db->db_evict_func == NULL)
226fa9e4066Sahrens 		return;
227fa9e4066Sahrens 
228c717a561Smaybee 	if (db->db_user_data_ptr_ptr)
229c717a561Smaybee 		*db->db_user_data_ptr_ptr = db->db.db_data;
230c717a561Smaybee 	db->db_evict_func(&db->db, db->db_user_ptr);
231c717a561Smaybee 	db->db_user_ptr = NULL;
232c717a561Smaybee 	db->db_user_data_ptr_ptr = NULL;
233c717a561Smaybee 	db->db_evict_func = NULL;
234fa9e4066Sahrens }
235fa9e4066Sahrens 
236744947dcSTom Erickson boolean_t
237744947dcSTom Erickson dbuf_is_metadata(dmu_buf_impl_t *db)
238744947dcSTom Erickson {
239744947dcSTom Erickson 	if (db->db_level > 0) {
240744947dcSTom Erickson 		return (B_TRUE);
241744947dcSTom Erickson 	} else {
242744947dcSTom Erickson 		boolean_t is_metadata;
243744947dcSTom Erickson 
244744947dcSTom Erickson 		DB_DNODE_ENTER(db);
245ad135b5dSChristopher Siden 		is_metadata = DMU_OT_IS_METADATA(DB_DNODE(db)->dn_type);
246744947dcSTom Erickson 		DB_DNODE_EXIT(db);
247744947dcSTom Erickson 
248744947dcSTom Erickson 		return (is_metadata);
249744947dcSTom Erickson 	}
250744947dcSTom Erickson }
251744947dcSTom Erickson 
252ea8dc4b6Seschrock void
253ea8dc4b6Seschrock dbuf_evict(dmu_buf_impl_t *db)
254ea8dc4b6Seschrock {
255ea8dc4b6Seschrock 	ASSERT(MUTEX_HELD(&db->db_mtx));
256ea8dc4b6Seschrock 	ASSERT(db->db_buf == NULL);
257c717a561Smaybee 	ASSERT(db->db_data_pending == NULL);
258ea8dc4b6Seschrock 
259ea8dc4b6Seschrock 	dbuf_clear(db);
260ea8dc4b6Seschrock 	dbuf_destroy(db);
261ea8dc4b6Seschrock }
262ea8dc4b6Seschrock 
263fa9e4066Sahrens void
264fa9e4066Sahrens dbuf_init(void)
265fa9e4066Sahrens {
266ea8dc4b6Seschrock 	uint64_t hsize = 1ULL << 16;
267fa9e4066Sahrens 	dbuf_hash_table_t *h = &dbuf_hash_table;
268fa9e4066Sahrens 	int i;
269fa9e4066Sahrens 
270fa9e4066Sahrens 	/*
271fa9e4066Sahrens 	 * The hash table is big enough to fill all of physical memory
272ea8dc4b6Seschrock 	 * with an average 4K block size.  The table will take up
273ea8dc4b6Seschrock 	 * totalmem*sizeof(void*)/4K (i.e. 2MB/GB with 8-byte pointers).
274fa9e4066Sahrens 	 */
275ea8dc4b6Seschrock 	while (hsize * 4096 < physmem * PAGESIZE)
276fa9e4066Sahrens 		hsize <<= 1;
277fa9e4066Sahrens 
278ea8dc4b6Seschrock retry:
279fa9e4066Sahrens 	h->hash_table_mask = hsize - 1;
280ea8dc4b6Seschrock 	h->hash_table = kmem_zalloc(hsize * sizeof (void *), KM_NOSLEEP);
281ea8dc4b6Seschrock 	if (h->hash_table == NULL) {
282ea8dc4b6Seschrock 		/* XXX - we should really return an error instead of assert */
283ea8dc4b6Seschrock 		ASSERT(hsize > (1ULL << 10));
284ea8dc4b6Seschrock 		hsize >>= 1;
285ea8dc4b6Seschrock 		goto retry;
286ea8dc4b6Seschrock 	}
287fa9e4066Sahrens 
288fa9e4066Sahrens 	dbuf_cache = kmem_cache_create("dmu_buf_impl_t",
289fa9e4066Sahrens 	    sizeof (dmu_buf_impl_t),
290fa9e4066Sahrens 	    0, dbuf_cons, dbuf_dest, NULL, NULL, NULL, 0);
291fa9e4066Sahrens 
292fa9e4066Sahrens 	for (i = 0; i < DBUF_MUTEXES; i++)
293fa9e4066Sahrens 		mutex_init(&h->hash_mutexes[i], NULL, MUTEX_DEFAULT, NULL);
294fa9e4066Sahrens }
295fa9e4066Sahrens 
296fa9e4066Sahrens void
297fa9e4066Sahrens dbuf_fini(void)
298fa9e4066Sahrens {
299fa9e4066Sahrens 	dbuf_hash_table_t *h = &dbuf_hash_table;
300fa9e4066Sahrens 	int i;
301fa9e4066Sahrens 
302fa9e4066Sahrens 	for (i = 0; i < DBUF_MUTEXES; i++)
303fa9e4066Sahrens 		mutex_destroy(&h->hash_mutexes[i]);
304fa9e4066Sahrens 	kmem_free(h->hash_table, (h->hash_table_mask + 1) * sizeof (void *));
305fa9e4066Sahrens 	kmem_cache_destroy(dbuf_cache);
306fa9e4066Sahrens }
307fa9e4066Sahrens 
308fa9e4066Sahrens /*
309fa9e4066Sahrens  * Other stuff.
310fa9e4066Sahrens  */
311fa9e4066Sahrens 
3129c9dc39aSek #ifdef ZFS_DEBUG
313fa9e4066Sahrens static void
314fa9e4066Sahrens dbuf_verify(dmu_buf_impl_t *db)
315fa9e4066Sahrens {
316744947dcSTom Erickson 	dnode_t *dn;
317b24ab676SJeff Bonwick 	dbuf_dirty_record_t *dr;
318fa9e4066Sahrens 
319fa9e4066Sahrens 	ASSERT(MUTEX_HELD(&db->db_mtx));
320fa9e4066Sahrens 
321fa9e4066Sahrens 	if (!(zfs_flags & ZFS_DEBUG_DBUF_VERIFY))
322fa9e4066Sahrens 		return;
323fa9e4066Sahrens 
324fa9e4066Sahrens 	ASSERT(db->db_objset != NULL);
325744947dcSTom Erickson 	DB_DNODE_ENTER(db);
326744947dcSTom Erickson 	dn = DB_DNODE(db);
327fa9e4066Sahrens 	if (dn == NULL) {
328fa9e4066Sahrens 		ASSERT(db->db_parent == NULL);
329fa9e4066Sahrens 		ASSERT(db->db_blkptr == NULL);
330fa9e4066Sahrens 	} else {
331fa9e4066Sahrens 		ASSERT3U(db->db.db_object, ==, dn->dn_object);
332fa9e4066Sahrens 		ASSERT3P(db->db_objset, ==, dn->dn_objset);
333fa9e4066Sahrens 		ASSERT3U(db->db_level, <, dn->dn_nlevels);
334744947dcSTom Erickson 		ASSERT(db->db_blkid == DMU_BONUS_BLKID ||
335744947dcSTom Erickson 		    db->db_blkid == DMU_SPILL_BLKID ||
336*0f6d88adSAlex Reece 		    !avl_is_empty(&dn->dn_dbufs));
337fa9e4066Sahrens 	}
3380a586ceaSMark Shellenbaum 	if (db->db_blkid == DMU_BONUS_BLKID) {
339fa9e4066Sahrens 		ASSERT(dn != NULL);
3401934e92fSmaybee 		ASSERT3U(db->db.db_size, >=, dn->dn_bonuslen);
3410a586ceaSMark Shellenbaum 		ASSERT3U(db->db.db_offset, ==, DMU_BONUS_BLKID);
3420a586ceaSMark Shellenbaum 	} else if (db->db_blkid == DMU_SPILL_BLKID) {
3430a586ceaSMark Shellenbaum 		ASSERT(dn != NULL);
3440a586ceaSMark Shellenbaum 		ASSERT3U(db->db.db_size, >=, dn->dn_bonuslen);
345fb09f5aaSMadhav Suresh 		ASSERT0(db->db.db_offset);
346fa9e4066Sahrens 	} else {
347fa9e4066Sahrens 		ASSERT3U(db->db.db_offset, ==, db->db_blkid * db->db.db_size);
348fa9e4066Sahrens 	}
349fa9e4066Sahrens 
350b24ab676SJeff Bonwick 	for (dr = db->db_data_pending; dr != NULL; dr = dr->dr_next)
351b24ab676SJeff Bonwick 		ASSERT(dr->dr_dbuf == db);
352b24ab676SJeff Bonwick 
353b24ab676SJeff Bonwick 	for (dr = db->db_last_dirty; dr != NULL; dr = dr->dr_next)
354b24ab676SJeff Bonwick 		ASSERT(dr->dr_dbuf == db);
355b24ab676SJeff Bonwick 
35688b7b0f2SMatthew Ahrens 	/*
35788b7b0f2SMatthew Ahrens 	 * We can't assert that db_size matches dn_datablksz because it
35888b7b0f2SMatthew Ahrens 	 * can be momentarily different when another thread is doing
35988b7b0f2SMatthew Ahrens 	 * dnode_set_blksz().
36088b7b0f2SMatthew Ahrens 	 */
36188b7b0f2SMatthew Ahrens 	if (db->db_level == 0 && db->db.db_object == DMU_META_DNODE_OBJECT) {
362b24ab676SJeff Bonwick 		dr = db->db_data_pending;
36388b7b0f2SMatthew Ahrens 		/*
36488b7b0f2SMatthew Ahrens 		 * It should only be modified in syncing context, so
36588b7b0f2SMatthew Ahrens 		 * make sure we only have one copy of the data.
36688b7b0f2SMatthew Ahrens 		 */
36788b7b0f2SMatthew Ahrens 		ASSERT(dr == NULL || dr->dt.dl.dr_data == db->db_buf);
368fa9e4066Sahrens 	}
369fa9e4066Sahrens 
370fa9e4066Sahrens 	/* verify db->db_blkptr */
371fa9e4066Sahrens 	if (db->db_blkptr) {
372fa9e4066Sahrens 		if (db->db_parent == dn->dn_dbuf) {
373fa9e4066Sahrens 			/* db is pointed to by the dnode */
374fa9e4066Sahrens 			/* ASSERT3U(db->db_blkid, <, dn->dn_nblkptr); */
37514843421SMatthew Ahrens 			if (DMU_OBJECT_IS_SPECIAL(db->db.db_object))
376fa9e4066Sahrens 				ASSERT(db->db_parent == NULL);
377fa9e4066Sahrens 			else
378fa9e4066Sahrens 				ASSERT(db->db_parent != NULL);
3790a586ceaSMark Shellenbaum 			if (db->db_blkid != DMU_SPILL_BLKID)
3800a586ceaSMark Shellenbaum 				ASSERT3P(db->db_blkptr, ==,
3810a586ceaSMark Shellenbaum 				    &dn->dn_phys->dn_blkptr[db->db_blkid]);
382fa9e4066Sahrens 		} else {
383fa9e4066Sahrens 			/* db is pointed to by an indirect block */
384fa9e4066Sahrens 			int epb = db->db_parent->db.db_size >> SPA_BLKPTRSHIFT;
385fa9e4066Sahrens 			ASSERT3U(db->db_parent->db_level, ==, db->db_level+1);
386fa9e4066Sahrens 			ASSERT3U(db->db_parent->db.db_object, ==,
387fa9e4066Sahrens 			    db->db.db_object);
388fa9e4066Sahrens 			/*
389fa9e4066Sahrens 			 * dnode_grow_indblksz() can make this fail if we don't
390fa9e4066Sahrens 			 * have the struct_rwlock.  XXX indblksz no longer
391fa9e4066Sahrens 			 * grows.  safe to do this now?
392fa9e4066Sahrens 			 */
393744947dcSTom Erickson 			if (RW_WRITE_HELD(&dn->dn_struct_rwlock)) {
394fa9e4066Sahrens 				ASSERT3P(db->db_blkptr, ==,
395fa9e4066Sahrens 				    ((blkptr_t *)db->db_parent->db.db_data +
396fa9e4066Sahrens 				    db->db_blkid % epb));
397fa9e4066Sahrens 			}
398fa9e4066Sahrens 		}
399fa9e4066Sahrens 	}
400fa9e4066Sahrens 	if ((db->db_blkptr == NULL || BP_IS_HOLE(db->db_blkptr)) &&
4013f9d6ad7SLin Ling 	    (db->db_buf == NULL || db->db_buf->b_data) &&
4020a586ceaSMark Shellenbaum 	    db->db.db_data && db->db_blkid != DMU_BONUS_BLKID &&
403fa9e4066Sahrens 	    db->db_state != DB_FILL && !dn->dn_free_txg) {
404fa9e4066Sahrens 		/*
405fa9e4066Sahrens 		 * If the blkptr isn't set but they have nonzero data,
406fa9e4066Sahrens 		 * it had better be dirty, otherwise we'll lose that
407fa9e4066Sahrens 		 * data when we evict this buffer.
408fa9e4066Sahrens 		 */
409fa9e4066Sahrens 		if (db->db_dirtycnt == 0) {
410fa9e4066Sahrens 			uint64_t *buf = db->db.db_data;
411fa9e4066Sahrens 			int i;
412fa9e4066Sahrens 
413fa9e4066Sahrens 			for (i = 0; i < db->db.db_size >> 3; i++) {
414fa9e4066Sahrens 				ASSERT(buf[i] == 0);
415fa9e4066Sahrens 			}
416fa9e4066Sahrens 		}
417fa9e4066Sahrens 	}
418744947dcSTom Erickson 	DB_DNODE_EXIT(db);
419fa9e4066Sahrens }
4209c9dc39aSek #endif
421fa9e4066Sahrens 
422fa9e4066Sahrens static void
423fa9e4066Sahrens dbuf_update_data(dmu_buf_impl_t *db)
424fa9e4066Sahrens {
425fa9e4066Sahrens 	ASSERT(MUTEX_HELD(&db->db_mtx));
426c717a561Smaybee 	if (db->db_level == 0 && db->db_user_data_ptr_ptr) {
427fa9e4066Sahrens 		ASSERT(!refcount_is_zero(&db->db_holds));
428c717a561Smaybee 		*db->db_user_data_ptr_ptr = db->db.db_data;
429fa9e4066Sahrens 	}
430fa9e4066Sahrens }
431fa9e4066Sahrens 
432fa9e4066Sahrens static void
433fa9e4066Sahrens dbuf_set_data(dmu_buf_impl_t *db, arc_buf_t *buf)
434fa9e4066Sahrens {
435fa9e4066Sahrens 	ASSERT(MUTEX_HELD(&db->db_mtx));
436fa9e4066Sahrens 	db->db_buf = buf;
437ea8dc4b6Seschrock 	if (buf != NULL) {
438ea8dc4b6Seschrock 		ASSERT(buf->b_data != NULL);
439ea8dc4b6Seschrock 		db->db.db_data = buf->b_data;
440ea8dc4b6Seschrock 		if (!arc_released(buf))
441ea8dc4b6Seschrock 			arc_set_callback(buf, dbuf_do_evict, db);
442ea8dc4b6Seschrock 		dbuf_update_data(db);
443ea8dc4b6Seschrock 	} else {
444ea8dc4b6Seschrock 		dbuf_evict_user(db);
445ea8dc4b6Seschrock 		db->db.db_data = NULL;
44682c9918fSTim Haley 		if (db->db_state != DB_NOFILL)
44782c9918fSTim Haley 			db->db_state = DB_UNCACHED;
448ea8dc4b6Seschrock 	}
449fa9e4066Sahrens }
450fa9e4066Sahrens 
451c242f9a0Schunli zhang - Sun Microsystems - Irvine United States /*
452c242f9a0Schunli zhang - Sun Microsystems - Irvine United States  * Loan out an arc_buf for read.  Return the loaned arc_buf.
453c242f9a0Schunli zhang - Sun Microsystems - Irvine United States  */
454c242f9a0Schunli zhang - Sun Microsystems - Irvine United States arc_buf_t *
455c242f9a0Schunli zhang - Sun Microsystems - Irvine United States dbuf_loan_arcbuf(dmu_buf_impl_t *db)
456c242f9a0Schunli zhang - Sun Microsystems - Irvine United States {
457c242f9a0Schunli zhang - Sun Microsystems - Irvine United States 	arc_buf_t *abuf;
458c242f9a0Schunli zhang - Sun Microsystems - Irvine United States 
459c242f9a0Schunli zhang - Sun Microsystems - Irvine United States 	mutex_enter(&db->db_mtx);
460c242f9a0Schunli zhang - Sun Microsystems - Irvine United States 	if (arc_released(db->db_buf) || refcount_count(&db->db_holds) > 1) {
461c242f9a0Schunli zhang - Sun Microsystems - Irvine United States 		int blksz = db->db.db_size;
46243466aaeSMax Grossman 		spa_t *spa = db->db_objset->os_spa;
463744947dcSTom Erickson 
464c242f9a0Schunli zhang - Sun Microsystems - Irvine United States 		mutex_exit(&db->db_mtx);
465744947dcSTom Erickson 		abuf = arc_loan_buf(spa, blksz);
466c242f9a0Schunli zhang - Sun Microsystems - Irvine United States 		bcopy(db->db.db_data, abuf->b_data, blksz);
467c242f9a0Schunli zhang - Sun Microsystems - Irvine United States 	} else {
468c242f9a0Schunli zhang - Sun Microsystems - Irvine United States 		abuf = db->db_buf;
469c242f9a0Schunli zhang - Sun Microsystems - Irvine United States 		arc_loan_inuse_buf(abuf, db);
470c242f9a0Schunli zhang - Sun Microsystems - Irvine United States 		dbuf_set_data(db, NULL);
471c242f9a0Schunli zhang - Sun Microsystems - Irvine United States 		mutex_exit(&db->db_mtx);
472c242f9a0Schunli zhang - Sun Microsystems - Irvine United States 	}
473c242f9a0Schunli zhang - Sun Microsystems - Irvine United States 	return (abuf);
474c242f9a0Schunli zhang - Sun Microsystems - Irvine United States }
475c242f9a0Schunli zhang - Sun Microsystems - Irvine United States 
476fa9e4066Sahrens uint64_t
477fa9e4066Sahrens dbuf_whichblock(dnode_t *dn, uint64_t offset)
478fa9e4066Sahrens {
479fa9e4066Sahrens 	if (dn->dn_datablkshift) {
480fa9e4066Sahrens 		return (offset >> dn->dn_datablkshift);
481fa9e4066Sahrens 	} else {
482fa9e4066Sahrens 		ASSERT3U(offset, <, dn->dn_datablksz);
483fa9e4066Sahrens 		return (0);
484fa9e4066Sahrens 	}
485fa9e4066Sahrens }
486fa9e4066Sahrens 
487fa9e4066Sahrens static void
488fa9e4066Sahrens dbuf_read_done(zio_t *zio, arc_buf_t *buf, void *vdb)
489fa9e4066Sahrens {
490fa9e4066Sahrens 	dmu_buf_impl_t *db = vdb;
491fa9e4066Sahrens 
492fa9e4066Sahrens 	mutex_enter(&db->db_mtx);
493fa9e4066Sahrens 	ASSERT3U(db->db_state, ==, DB_READ);
494fa9e4066Sahrens 	/*
495fa9e4066Sahrens 	 * All reads are synchronous, so we must have a hold on the dbuf
496fa9e4066Sahrens 	 */
497fa9e4066Sahrens 	ASSERT(refcount_count(&db->db_holds) > 0);
498ea8dc4b6Seschrock 	ASSERT(db->db_buf == NULL);
499fa9e4066Sahrens 	ASSERT(db->db.db_data == NULL);
500c717a561Smaybee 	if (db->db_level == 0 && db->db_freed_in_flight) {
501fa9e4066Sahrens 		/* we were freed in flight; disregard any error */
502fa9e4066Sahrens 		arc_release(buf, db);
503fa9e4066Sahrens 		bzero(buf->b_data, db->db.db_size);
5046b4acc8bSahrens 		arc_buf_freeze(buf);
505c717a561Smaybee 		db->db_freed_in_flight = FALSE;
506fa9e4066Sahrens 		dbuf_set_data(db, buf);
507fa9e4066Sahrens 		db->db_state = DB_CACHED;
508fa9e4066Sahrens 	} else if (zio == NULL || zio->io_error == 0) {
509fa9e4066Sahrens 		dbuf_set_data(db, buf);
510fa9e4066Sahrens 		db->db_state = DB_CACHED;
511fa9e4066Sahrens 	} else {
5120a586ceaSMark Shellenbaum 		ASSERT(db->db_blkid != DMU_BONUS_BLKID);
513fa9e4066Sahrens 		ASSERT3P(db->db_buf, ==, NULL);
5143b2aab18SMatthew Ahrens 		VERIFY(arc_buf_remove_ref(buf, db));
515ea8dc4b6Seschrock 		db->db_state = DB_UNCACHED;
516fa9e4066Sahrens 	}
517fa9e4066Sahrens 	cv_broadcast(&db->db_changed);
5183f9d6ad7SLin Ling 	dbuf_rele_and_unlock(db, NULL);
519fa9e4066Sahrens }
520fa9e4066Sahrens 
521ea8dc4b6Seschrock static void
52213506d1eSmaybee dbuf_read_impl(dmu_buf_impl_t *db, zio_t *zio, uint32_t *flags)
523fa9e4066Sahrens {
524744947dcSTom Erickson 	dnode_t *dn;
5257802d7bfSMatthew Ahrens 	zbookmark_phys_t zb;
52613506d1eSmaybee 	uint32_t aflags = ARC_NOWAIT;
527fa9e4066Sahrens 
528744947dcSTom Erickson 	DB_DNODE_ENTER(db);
529744947dcSTom Erickson 	dn = DB_DNODE(db);
530fa9e4066Sahrens 	ASSERT(!refcount_is_zero(&db->db_holds));
531fa9e4066Sahrens 	/* We need the struct_rwlock to prevent db_blkptr from changing. */
532088f3894Sahrens 	ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock));
533ea8dc4b6Seschrock 	ASSERT(MUTEX_HELD(&db->db_mtx));
534ea8dc4b6Seschrock 	ASSERT(db->db_state == DB_UNCACHED);
535ea8dc4b6Seschrock 	ASSERT(db->db_buf == NULL);
536fa9e4066Sahrens 
5370a586ceaSMark Shellenbaum 	if (db->db_blkid == DMU_BONUS_BLKID) {
538cf04dda1SMark Maybee 		int bonuslen = MIN(dn->dn_bonuslen, dn->dn_phys->dn_bonuslen);
5391934e92fSmaybee 
5401934e92fSmaybee 		ASSERT3U(bonuslen, <=, db->db.db_size);
541ea8dc4b6Seschrock 		db->db.db_data = zio_buf_alloc(DN_MAX_BONUSLEN);
5425a98e54bSBrendan Gregg - Sun Microsystems 		arc_space_consume(DN_MAX_BONUSLEN, ARC_SPACE_OTHER);
5431934e92fSmaybee 		if (bonuslen < DN_MAX_BONUSLEN)
544ea8dc4b6Seschrock 			bzero(db->db.db_data, DN_MAX_BONUSLEN);
545cf04dda1SMark Maybee 		if (bonuslen)
546cf04dda1SMark Maybee 			bcopy(DN_BONUS(dn->dn_phys), db->db.db_data, bonuslen);
547744947dcSTom Erickson 		DB_DNODE_EXIT(db);
548ea8dc4b6Seschrock 		dbuf_update_data(db);
549fa9e4066Sahrens 		db->db_state = DB_CACHED;
550fa9e4066Sahrens 		mutex_exit(&db->db_mtx);
551fa9e4066Sahrens 		return;
552fa9e4066Sahrens 	}
553fa9e4066Sahrens 
5541c8564a7SMark Maybee 	/*
5551c8564a7SMark Maybee 	 * Recheck BP_IS_HOLE() after dnode_block_freed() in case dnode_sync()
5561c8564a7SMark Maybee 	 * processes the delete record and clears the bp while we are waiting
5571c8564a7SMark Maybee 	 * for the dn_mtx (resulting in a "no" from block_freed).
5581c8564a7SMark Maybee 	 */
559088f3894Sahrens 	if (db->db_blkptr == NULL || BP_IS_HOLE(db->db_blkptr) ||
5601c8564a7SMark Maybee 	    (db->db_level == 0 && (dnode_block_freed(dn, db->db_blkid) ||
5611c8564a7SMark Maybee 	    BP_IS_HOLE(db->db_blkptr)))) {
562ad23a2dbSjohansen 		arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db);
563ad23a2dbSjohansen 
564744947dcSTom Erickson 		DB_DNODE_EXIT(db);
56543466aaeSMax Grossman 		dbuf_set_data(db, arc_buf_alloc(db->db_objset->os_spa,
56643466aaeSMax Grossman 		    db->db.db_size, db, type));
567fa9e4066Sahrens 		bzero(db->db.db_data, db->db.db_size);
568fa9e4066Sahrens 		db->db_state = DB_CACHED;
56913506d1eSmaybee 		*flags |= DB_RF_CACHED;
570fa9e4066Sahrens 		mutex_exit(&db->db_mtx);
571fa9e4066Sahrens 		return;
572fa9e4066Sahrens 	}
573fa9e4066Sahrens 
574744947dcSTom Erickson 	DB_DNODE_EXIT(db);
575744947dcSTom Erickson 
576fa9e4066Sahrens 	db->db_state = DB_READ;
577fa9e4066Sahrens 	mutex_exit(&db->db_mtx);
578fa9e4066Sahrens 
5793baa08fcSek 	if (DBUF_IS_L2CACHEABLE(db))
5803baa08fcSek 		aflags |= ARC_L2CACHE;
581aad02571SSaso Kiselkov 	if (DBUF_IS_L2COMPRESSIBLE(db))
582aad02571SSaso Kiselkov 		aflags |= ARC_L2COMPRESS;
5833baa08fcSek 
584b24ab676SJeff Bonwick 	SET_BOOKMARK(&zb, db->db_objset->os_dsl_dataset ?
585b24ab676SJeff Bonwick 	    db->db_objset->os_dsl_dataset->ds_object : DMU_META_OBJSET,
586b24ab676SJeff Bonwick 	    db->db.db_object, db->db_level, db->db_blkid);
587ea8dc4b6Seschrock 
588ea8dc4b6Seschrock 	dbuf_add_ref(db, NULL);
589088f3894Sahrens 
59043466aaeSMax Grossman 	(void) arc_read(zio, db->db_objset->os_spa, db->db_blkptr,
591fa9e4066Sahrens 	    dbuf_read_done, db, ZIO_PRIORITY_SYNC_READ,
59213506d1eSmaybee 	    (*flags & DB_RF_CANFAIL) ? ZIO_FLAG_CANFAIL : ZIO_FLAG_MUSTSUCCEED,
59313506d1eSmaybee 	    &aflags, &zb);
59413506d1eSmaybee 	if (aflags & ARC_CACHED)
59513506d1eSmaybee 		*flags |= DB_RF_CACHED;
596fa9e4066Sahrens }
597fa9e4066Sahrens 
598ea8dc4b6Seschrock int
599ea8dc4b6Seschrock dbuf_read(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags)
600fa9e4066Sahrens {
601ea8dc4b6Seschrock 	int err = 0;
60243466aaeSMax Grossman 	boolean_t havepzio = (zio != NULL);
60343466aaeSMax Grossman 	boolean_t prefetch;
604744947dcSTom Erickson 	dnode_t *dn;
605fa9e4066Sahrens 
606fa9e4066Sahrens 	/*
607fa9e4066Sahrens 	 * We don't have to hold the mutex to check db_state because it
608fa9e4066Sahrens 	 * can't be freed while we have a hold on the buffer.
609fa9e4066Sahrens 	 */
610fa9e4066Sahrens 	ASSERT(!refcount_is_zero(&db->db_holds));
611fa9e4066Sahrens 
61282c9918fSTim Haley 	if (db->db_state == DB_NOFILL)
613be6fd75aSMatthew Ahrens 		return (SET_ERROR(EIO));
61482c9918fSTim Haley 
615744947dcSTom Erickson 	DB_DNODE_ENTER(db);
616744947dcSTom Erickson 	dn = DB_DNODE(db);
617ea8dc4b6Seschrock 	if ((flags & DB_RF_HAVESTRUCT) == 0)
618744947dcSTom Erickson 		rw_enter(&dn->dn_struct_rwlock, RW_READER);
619ea8dc4b6Seschrock 
6200a586ceaSMark Shellenbaum 	prefetch = db->db_level == 0 && db->db_blkid != DMU_BONUS_BLKID &&
621744947dcSTom Erickson 	    (flags & DB_RF_NOPREFETCH) == 0 && dn != NULL &&
6223baa08fcSek 	    DBUF_IS_CACHEABLE(db);
62313506d1eSmaybee 
624ea8dc4b6Seschrock 	mutex_enter(&db->db_mtx);
625ea8dc4b6Seschrock 	if (db->db_state == DB_CACHED) {
626ea8dc4b6Seschrock 		mutex_exit(&db->db_mtx);
62713506d1eSmaybee 		if (prefetch)
628744947dcSTom Erickson 			dmu_zfetch(&dn->dn_zfetch, db->db.db_offset,
62913506d1eSmaybee 			    db->db.db_size, TRUE);
630fa9e4066Sahrens 		if ((flags & DB_RF_HAVESTRUCT) == 0)
631744947dcSTom Erickson 			rw_exit(&dn->dn_struct_rwlock);
632744947dcSTom Erickson 		DB_DNODE_EXIT(db);
633ea8dc4b6Seschrock 	} else if (db->db_state == DB_UNCACHED) {
634744947dcSTom Erickson 		spa_t *spa = dn->dn_objset->os_spa;
635744947dcSTom Erickson 
636744947dcSTom Erickson 		if (zio == NULL)
637744947dcSTom Erickson 			zio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL);
63813506d1eSmaybee 		dbuf_read_impl(db, zio, &flags);
63913506d1eSmaybee 
640ea8dc4b6Seschrock 		/* dbuf_read_impl has dropped db_mtx for us */
641ea8dc4b6Seschrock 
64213506d1eSmaybee 		if (prefetch)
643744947dcSTom Erickson 			dmu_zfetch(&dn->dn_zfetch, db->db.db_offset,
64413506d1eSmaybee 			    db->db.db_size, flags & DB_RF_CACHED);
645ea8dc4b6Seschrock 
646fa9e4066Sahrens 		if ((flags & DB_RF_HAVESTRUCT) == 0)
647744947dcSTom Erickson 			rw_exit(&dn->dn_struct_rwlock);
648744947dcSTom Erickson 		DB_DNODE_EXIT(db);
649fa9e4066Sahrens 
650ea8dc4b6Seschrock 		if (!havepzio)
651ea8dc4b6Seschrock 			err = zio_wait(zio);
652ea8dc4b6Seschrock 	} else {
6533e30c24aSWill Andrews 		/*
6543e30c24aSWill Andrews 		 * Another reader came in while the dbuf was in flight
6553e30c24aSWill Andrews 		 * between UNCACHED and CACHED.  Either a writer will finish
6563e30c24aSWill Andrews 		 * writing the buffer (sending the dbuf to CACHED) or the
6573e30c24aSWill Andrews 		 * first reader's request will reach the read_done callback
6583e30c24aSWill Andrews 		 * and send the dbuf to CACHED.  Otherwise, a failure
6593e30c24aSWill Andrews 		 * occurred and the dbuf went to UNCACHED.
6603e30c24aSWill Andrews 		 */
66113506d1eSmaybee 		mutex_exit(&db->db_mtx);
66213506d1eSmaybee 		if (prefetch)
663744947dcSTom Erickson 			dmu_zfetch(&dn->dn_zfetch, db->db.db_offset,
66413506d1eSmaybee 			    db->db.db_size, TRUE);
665ea8dc4b6Seschrock 		if ((flags & DB_RF_HAVESTRUCT) == 0)
666744947dcSTom Erickson 			rw_exit(&dn->dn_struct_rwlock);
667744947dcSTom Erickson 		DB_DNODE_EXIT(db);
66813506d1eSmaybee 
6693e30c24aSWill Andrews 		/* Skip the wait per the caller's request. */
67013506d1eSmaybee 		mutex_enter(&db->db_mtx);
671ea8dc4b6Seschrock 		if ((flags & DB_RF_NEVERWAIT) == 0) {
672ea8dc4b6Seschrock 			while (db->db_state == DB_READ ||
673ea8dc4b6Seschrock 			    db->db_state == DB_FILL) {
674ea8dc4b6Seschrock 				ASSERT(db->db_state == DB_READ ||
675ea8dc4b6Seschrock 				    (flags & DB_RF_HAVESTRUCT) == 0);
676ea8dc4b6Seschrock 				cv_wait(&db->db_changed, &db->db_mtx);
677ea8dc4b6Seschrock 			}
678ea8dc4b6Seschrock 			if (db->db_state == DB_UNCACHED)
679be6fd75aSMatthew Ahrens 				err = SET_ERROR(EIO);
680ea8dc4b6Seschrock 		}
681ea8dc4b6Seschrock 		mutex_exit(&db->db_mtx);
682fa9e4066Sahrens 	}
683fa9e4066Sahrens 
684ea8dc4b6Seschrock 	ASSERT(err || havepzio || db->db_state == DB_CACHED);
685ea8dc4b6Seschrock 	return (err);
686fa9e4066Sahrens }
687fa9e4066Sahrens 
688fa9e4066Sahrens static void
689fa9e4066Sahrens dbuf_noread(dmu_buf_impl_t *db)
690fa9e4066Sahrens {
691fa9e4066Sahrens 	ASSERT(!refcount_is_zero(&db->db_holds));
6920a586ceaSMark Shellenbaum 	ASSERT(db->db_blkid != DMU_BONUS_BLKID);
693fa9e4066Sahrens 	mutex_enter(&db->db_mtx);
694fa9e4066Sahrens 	while (db->db_state == DB_READ || db->db_state == DB_FILL)
695fa9e4066Sahrens 		cv_wait(&db->db_changed, &db->db_mtx);
696fa9e4066Sahrens 	if (db->db_state == DB_UNCACHED) {
697ad23a2dbSjohansen 		arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db);
69843466aaeSMax Grossman 		spa_t *spa = db->db_objset->os_spa;
699ad23a2dbSjohansen 
700ea8dc4b6Seschrock 		ASSERT(db->db_buf == NULL);
701fa9e4066Sahrens 		ASSERT(db->db.db_data == NULL);
702744947dcSTom Erickson 		dbuf_set_data(db, arc_buf_alloc(spa, db->db.db_size, db, type));
703fa9e4066Sahrens 		db->db_state = DB_FILL;
70482c9918fSTim Haley 	} else if (db->db_state == DB_NOFILL) {
70582c9918fSTim Haley 		dbuf_set_data(db, NULL);
706fa9e4066Sahrens 	} else {
707fa9e4066Sahrens 		ASSERT3U(db->db_state, ==, DB_CACHED);
708fa9e4066Sahrens 	}
709fa9e4066Sahrens 	mutex_exit(&db->db_mtx);
710fa9e4066Sahrens }
711fa9e4066Sahrens 
712fa9e4066Sahrens /*
713fa9e4066Sahrens  * This is our just-in-time copy function.  It makes a copy of
714fa9e4066Sahrens  * buffers, that have been modified in a previous transaction
715fa9e4066Sahrens  * group, before we modify them in the current active group.
716fa9e4066Sahrens  *
717fa9e4066Sahrens  * This function is used in two places: when we are dirtying a
718fa9e4066Sahrens  * buffer for the first time in a txg, and when we are freeing
719fa9e4066Sahrens  * a range in a dnode that includes this buffer.
720fa9e4066Sahrens  *
721fa9e4066Sahrens  * Note that when we are called from dbuf_free_range() we do
722fa9e4066Sahrens  * not put a hold on the buffer, we just traverse the active
723fa9e4066Sahrens  * dbuf list for the dnode.
724fa9e4066Sahrens  */
725fa9e4066Sahrens static void
726fa9e4066Sahrens dbuf_fix_old_data(dmu_buf_impl_t *db, uint64_t txg)
727fa9e4066Sahrens {
728c717a561Smaybee 	dbuf_dirty_record_t *dr = db->db_last_dirty;
729fa9e4066Sahrens 
730fa9e4066Sahrens 	ASSERT(MUTEX_HELD(&db->db_mtx));
731fa9e4066Sahrens 	ASSERT(db->db.db_data != NULL);
732c717a561Smaybee 	ASSERT(db->db_level == 0);
733c717a561Smaybee 	ASSERT(db->db.db_object != DMU_META_DNODE_OBJECT);
734fa9e4066Sahrens 
7354d31c452Smaybee 	if (dr == NULL ||
7364d31c452Smaybee 	    (dr->dt.dl.dr_data !=
7370a586ceaSMark Shellenbaum 	    ((db->db_blkid  == DMU_BONUS_BLKID) ? db->db.db_data : db->db_buf)))
738fa9e4066Sahrens 		return;
739fa9e4066Sahrens 
740fa9e4066Sahrens 	/*
741c717a561Smaybee 	 * If the last dirty record for this dbuf has not yet synced
742c717a561Smaybee 	 * and its referencing the dbuf data, either:
743744947dcSTom Erickson 	 *	reset the reference to point to a new copy,
744c717a561Smaybee 	 * or (if there a no active holders)
745c717a561Smaybee 	 *	just null out the current db_data pointer.
746fa9e4066Sahrens 	 */
747c717a561Smaybee 	ASSERT(dr->dr_txg >= txg - 2);
7480a586ceaSMark Shellenbaum 	if (db->db_blkid == DMU_BONUS_BLKID) {
749c717a561Smaybee 		/* Note that the data bufs here are zio_bufs */
750c717a561Smaybee 		dr->dt.dl.dr_data = zio_buf_alloc(DN_MAX_BONUSLEN);
7515a98e54bSBrendan Gregg - Sun Microsystems 		arc_space_consume(DN_MAX_BONUSLEN, ARC_SPACE_OTHER);
752c717a561Smaybee 		bcopy(db->db.db_data, dr->dt.dl.dr_data, DN_MAX_BONUSLEN);
753c717a561Smaybee 	} else if (refcount_count(&db->db_holds) > db->db_dirtycnt) {
754c717a561Smaybee 		int size = db->db.db_size;
755c717a561Smaybee 		arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db);
75643466aaeSMax Grossman 		spa_t *spa = db->db_objset->os_spa;
757744947dcSTom Erickson 
758744947dcSTom Erickson 		dr->dt.dl.dr_data = arc_buf_alloc(spa, size, db, type);
759c717a561Smaybee 		bcopy(db->db.db_data, dr->dt.dl.dr_data->b_data, size);
760c717a561Smaybee 	} else {
761c717a561Smaybee 		dbuf_set_data(db, NULL);
762fa9e4066Sahrens 	}
763fa9e4066Sahrens }
764fa9e4066Sahrens 
765c717a561Smaybee void
766c717a561Smaybee dbuf_unoverride(dbuf_dirty_record_t *dr)
767ea8dc4b6Seschrock {
768c717a561Smaybee 	dmu_buf_impl_t *db = dr->dr_dbuf;
769b24ab676SJeff Bonwick 	blkptr_t *bp = &dr->dt.dl.dr_overridden_by;
770c717a561Smaybee 	uint64_t txg = dr->dr_txg;
771ea8dc4b6Seschrock 
772ea8dc4b6Seschrock 	ASSERT(MUTEX_HELD(&db->db_mtx));
773c717a561Smaybee 	ASSERT(dr->dt.dl.dr_override_state != DR_IN_DMU_SYNC);
774c717a561Smaybee 	ASSERT(db->db_level == 0);
775ea8dc4b6Seschrock 
7760a586ceaSMark Shellenbaum 	if (db->db_blkid == DMU_BONUS_BLKID ||
777c717a561Smaybee 	    dr->dt.dl.dr_override_state == DR_NOT_OVERRIDDEN)
778c717a561Smaybee 		return;
779ea8dc4b6Seschrock 
780b24ab676SJeff Bonwick 	ASSERT(db->db_data_pending != dr);
781b24ab676SJeff Bonwick 
782c717a561Smaybee 	/* free this block */
78343466aaeSMax Grossman 	if (!BP_IS_HOLE(bp) && !dr->dt.dl.dr_nopwrite)
78443466aaeSMax Grossman 		zio_free(db->db_objset->os_spa, txg, bp);
785b24ab676SJeff Bonwick 
786c717a561Smaybee 	dr->dt.dl.dr_override_state = DR_NOT_OVERRIDDEN;
78780901aeaSGeorge Wilson 	dr->dt.dl.dr_nopwrite = B_FALSE;
78880901aeaSGeorge Wilson 
789c717a561Smaybee 	/*
790c717a561Smaybee 	 * Release the already-written buffer, so we leave it in
791c717a561Smaybee 	 * a consistent dirty state.  Note that all callers are
792c717a561Smaybee 	 * modifying the buffer, so they will immediately do
793c717a561Smaybee 	 * another (redundant) arc_release().  Therefore, leave
794c717a561Smaybee 	 * the buf thawed to save the effort of freezing &
795c717a561Smaybee 	 * immediately re-thawing it.
796c717a561Smaybee 	 */
797c717a561Smaybee 	arc_release(dr->dt.dl.dr_data, db);
798fa9e4066Sahrens }
799fa9e4066Sahrens 
800cdb0ab79Smaybee /*
801cdb0ab79Smaybee  * Evict (if its unreferenced) or clear (if its referenced) any level-0
802cdb0ab79Smaybee  * data blocks in the free range, so that any future readers will find
80343466aaeSMax Grossman  * empty blocks.
8042f3d8780SMatthew Ahrens  *
8052f3d8780SMatthew Ahrens  * This is a no-op if the dataset is in the middle of an incremental
8062f3d8780SMatthew Ahrens  * receive; see comment below for details.
807cdb0ab79Smaybee  */
808fa9e4066Sahrens void
809*0f6d88adSAlex Reece dbuf_free_range(dnode_t *dn, uint64_t start_blkid, uint64_t end_blkid,
810*0f6d88adSAlex Reece     dmu_tx_t *tx)
811fa9e4066Sahrens {
812*0f6d88adSAlex Reece 	dmu_buf_impl_t *db, *db_next, db_search;
813fa9e4066Sahrens 	uint64_t txg = tx->tx_txg;
814*0f6d88adSAlex Reece 	avl_index_t where;
815fa9e4066Sahrens 
816*0f6d88adSAlex Reece 	if (end_blkid > dn->dn_maxblkid && (end_blkid != DMU_SPILL_BLKID))
817*0f6d88adSAlex Reece 		end_blkid = dn->dn_maxblkid;
818*0f6d88adSAlex Reece 	dprintf_dnode(dn, "start=%llu end=%llu\n", start_blkid, end_blkid);
819*0f6d88adSAlex Reece 
820*0f6d88adSAlex Reece 	db_search.db_level = 0;
821*0f6d88adSAlex Reece 	db_search.db_blkid = start_blkid;
822*0f6d88adSAlex Reece 	db_search.db_creation = 0;
8232f3d8780SMatthew Ahrens 
824713d6c20SMatthew Ahrens 	mutex_enter(&dn->dn_dbufs_mtx);
825*0f6d88adSAlex Reece 	if (start_blkid >= dn->dn_unlisted_l0_blkid) {
826713d6c20SMatthew Ahrens 		/* There can't be any dbufs in this range; no need to search. */
827*0f6d88adSAlex Reece #ifdef DEBUG
828*0f6d88adSAlex Reece 		db = avl_find(&dn->dn_dbufs, &db_search, &where);
829*0f6d88adSAlex Reece 		ASSERT3P(db, ==, NULL);
830*0f6d88adSAlex Reece 		db = avl_nearest(&dn->dn_dbufs, where, AVL_AFTER);
831*0f6d88adSAlex Reece 		ASSERT(db == NULL || db->db_level > 0);
832*0f6d88adSAlex Reece #endif
833713d6c20SMatthew Ahrens 		mutex_exit(&dn->dn_dbufs_mtx);
834713d6c20SMatthew Ahrens 		return;
835713d6c20SMatthew Ahrens 	} else if (dmu_objset_is_receiving(dn->dn_objset)) {
8362f3d8780SMatthew Ahrens 		/*
837713d6c20SMatthew Ahrens 		 * If we are receiving, we expect there to be no dbufs in
838713d6c20SMatthew Ahrens 		 * the range to be freed, because receive modifies each
839713d6c20SMatthew Ahrens 		 * block at most once, and in offset order.  If this is
840713d6c20SMatthew Ahrens 		 * not the case, it can lead to performance problems,
841713d6c20SMatthew Ahrens 		 * so note that we unexpectedly took the slow path.
8422f3d8780SMatthew Ahrens 		 */
843713d6c20SMatthew Ahrens 		atomic_inc_64(&zfs_free_range_recv_miss);
8442f3d8780SMatthew Ahrens 	}
8452f3d8780SMatthew Ahrens 
846*0f6d88adSAlex Reece 	db = avl_find(&dn->dn_dbufs, &db_search, &where);
847*0f6d88adSAlex Reece 	ASSERT3P(db, ==, NULL);
848*0f6d88adSAlex Reece 	db = avl_nearest(&dn->dn_dbufs, where, AVL_AFTER);
849*0f6d88adSAlex Reece 
850*0f6d88adSAlex Reece 	for (; db != NULL; db = db_next) {
851*0f6d88adSAlex Reece 		db_next = AVL_NEXT(&dn->dn_dbufs, db);
8520a586ceaSMark Shellenbaum 		ASSERT(db->db_blkid != DMU_BONUS_BLKID);
853cdb0ab79Smaybee 
854*0f6d88adSAlex Reece 		if (db->db_level != 0 || db->db_blkid > end_blkid) {
855*0f6d88adSAlex Reece 			break;
856*0f6d88adSAlex Reece 		}
857*0f6d88adSAlex Reece 		ASSERT3U(db->db_blkid, >=, start_blkid);
858fa9e4066Sahrens 
859fa9e4066Sahrens 		/* found a level 0 buffer in the range */
8603b2aab18SMatthew Ahrens 		mutex_enter(&db->db_mtx);
8613b2aab18SMatthew Ahrens 		if (dbuf_undirty(db, tx)) {
8623b2aab18SMatthew Ahrens 			/* mutex has been dropped and dbuf destroyed */
863fa9e4066Sahrens 			continue;
8643b2aab18SMatthew Ahrens 		}
865fa9e4066Sahrens 
866ea8dc4b6Seschrock 		if (db->db_state == DB_UNCACHED ||
86782c9918fSTim Haley 		    db->db_state == DB_NOFILL ||
868ea8dc4b6Seschrock 		    db->db_state == DB_EVICTING) {
869fa9e4066Sahrens 			ASSERT(db->db.db_data == NULL);
870fa9e4066Sahrens 			mutex_exit(&db->db_mtx);
871fa9e4066Sahrens 			continue;
872fa9e4066Sahrens 		}
873c543ec06Sahrens 		if (db->db_state == DB_READ || db->db_state == DB_FILL) {
874c543ec06Sahrens 			/* will be handled in dbuf_read_done or dbuf_rele */
875c717a561Smaybee 			db->db_freed_in_flight = TRUE;
876fa9e4066Sahrens 			mutex_exit(&db->db_mtx);
877fa9e4066Sahrens 			continue;
878fa9e4066Sahrens 		}
879ea8dc4b6Seschrock 		if (refcount_count(&db->db_holds) == 0) {
880ea8dc4b6Seschrock 			ASSERT(db->db_buf);
881ea8dc4b6Seschrock 			dbuf_clear(db);
882ea8dc4b6Seschrock 			continue;
883ea8dc4b6Seschrock 		}
884c717a561Smaybee 		/* The dbuf is referenced */
885fa9e4066Sahrens 
886c717a561Smaybee 		if (db->db_last_dirty != NULL) {
887c717a561Smaybee 			dbuf_dirty_record_t *dr = db->db_last_dirty;
888c717a561Smaybee 
889c717a561Smaybee 			if (dr->dr_txg == txg) {
89044eda4d7Smaybee 				/*
891c717a561Smaybee 				 * This buffer is "in-use", re-adjust the file
892c717a561Smaybee 				 * size to reflect that this buffer may
893c717a561Smaybee 				 * contain new data when we sync.
89444eda4d7Smaybee 				 */
89506e0070dSMark Shellenbaum 				if (db->db_blkid != DMU_SPILL_BLKID &&
89606e0070dSMark Shellenbaum 				    db->db_blkid > dn->dn_maxblkid)
897c717a561Smaybee 					dn->dn_maxblkid = db->db_blkid;
898c717a561Smaybee 				dbuf_unoverride(dr);
899c717a561Smaybee 			} else {
900c717a561Smaybee 				/*
901c717a561Smaybee 				 * This dbuf is not dirty in the open context.
902c717a561Smaybee 				 * Either uncache it (if its not referenced in
903c717a561Smaybee 				 * the open context) or reset its contents to
904c717a561Smaybee 				 * empty.
905c717a561Smaybee 				 */
906c717a561Smaybee 				dbuf_fix_old_data(db, txg);
90744eda4d7Smaybee 			}
908ea8dc4b6Seschrock 		}
909c717a561Smaybee 		/* clear the contents if its cached */
910ea8dc4b6Seschrock 		if (db->db_state == DB_CACHED) {
911ea8dc4b6Seschrock 			ASSERT(db->db.db_data != NULL);
912fa9e4066Sahrens 			arc_release(db->db_buf, db);
913fa9e4066Sahrens 			bzero(db->db.db_data, db->db.db_size);
9146b4acc8bSahrens 			arc_buf_freeze(db->db_buf);
915fa9e4066Sahrens 		}
916ea8dc4b6Seschrock 
917fa9e4066Sahrens 		mutex_exit(&db->db_mtx);
918fa9e4066Sahrens 	}
919fa9e4066Sahrens 	mutex_exit(&dn->dn_dbufs_mtx);
920fa9e4066Sahrens }
921fa9e4066Sahrens 
922fa9e4066Sahrens static int
9231934e92fSmaybee dbuf_block_freeable(dmu_buf_impl_t *db)
924fa9e4066Sahrens {
925fa9e4066Sahrens 	dsl_dataset_t *ds = db->db_objset->os_dsl_dataset;
926fa9e4066Sahrens 	uint64_t birth_txg = 0;
927fa9e4066Sahrens 
928fa9e4066Sahrens 	/*
929fa9e4066Sahrens 	 * We don't need any locking to protect db_blkptr:
930c717a561Smaybee 	 * If it's syncing, then db_last_dirty will be set
931c717a561Smaybee 	 * so we'll ignore db_blkptr.
93243466aaeSMax Grossman 	 *
93343466aaeSMax Grossman 	 * This logic ensures that only block births for
93443466aaeSMax Grossman 	 * filled blocks are considered.
935fa9e4066Sahrens 	 */
936c717a561Smaybee 	ASSERT(MUTEX_HELD(&db->db_mtx));
93743466aaeSMax Grossman 	if (db->db_last_dirty && (db->db_blkptr == NULL ||
93843466aaeSMax Grossman 	    !BP_IS_HOLE(db->db_blkptr))) {
939c717a561Smaybee 		birth_txg = db->db_last_dirty->dr_txg;
94043466aaeSMax Grossman 	} else if (db->db_blkptr != NULL && !BP_IS_HOLE(db->db_blkptr)) {
941fa9e4066Sahrens 		birth_txg = db->db_blkptr->blk_birth;
94243466aaeSMax Grossman 	}
943fa9e4066Sahrens 
944837b568bSGeorge Wilson 	/*
94543466aaeSMax Grossman 	 * If this block don't exist or is in a snapshot, it can't be freed.
946837b568bSGeorge Wilson 	 * Don't pass the bp to dsl_dataset_block_freeable() since we
947837b568bSGeorge Wilson 	 * are holding the db_mtx lock and might deadlock if we are
948837b568bSGeorge Wilson 	 * prefetching a dedup-ed block.
949837b568bSGeorge Wilson 	 */
95043466aaeSMax Grossman 	if (birth_txg != 0)
9511934e92fSmaybee 		return (ds == NULL ||
952837b568bSGeorge Wilson 		    dsl_dataset_block_freeable(ds, NULL, birth_txg));
953fa9e4066Sahrens 	else
95443466aaeSMax Grossman 		return (B_FALSE);
955fa9e4066Sahrens }
956fa9e4066Sahrens 
957fa9e4066Sahrens void
958fa9e4066Sahrens dbuf_new_size(dmu_buf_impl_t *db, int size, dmu_tx_t *tx)
959fa9e4066Sahrens {
960fa9e4066Sahrens 	arc_buf_t *buf, *obuf;
961fa9e4066Sahrens 	int osize = db->db.db_size;
962ad23a2dbSjohansen 	arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db);
963744947dcSTom Erickson 	dnode_t *dn;
964fa9e4066Sahrens 
9650a586ceaSMark Shellenbaum 	ASSERT(db->db_blkid != DMU_BONUS_BLKID);
966ea8dc4b6Seschrock 
967744947dcSTom Erickson 	DB_DNODE_ENTER(db);
968744947dcSTom Erickson 	dn = DB_DNODE(db);
969744947dcSTom Erickson 
970fa9e4066Sahrens 	/* XXX does *this* func really need the lock? */
971744947dcSTom Erickson 	ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
972fa9e4066Sahrens 
973fa9e4066Sahrens 	/*
97443466aaeSMax Grossman 	 * This call to dmu_buf_will_dirty() with the dn_struct_rwlock held
975fa9e4066Sahrens 	 * is OK, because there can be no other references to the db
976fa9e4066Sahrens 	 * when we are changing its size, so no concurrent DB_FILL can
977fa9e4066Sahrens 	 * be happening.
978fa9e4066Sahrens 	 */
979ea8dc4b6Seschrock 	/*
980ea8dc4b6Seschrock 	 * XXX we should be doing a dbuf_read, checking the return
981ea8dc4b6Seschrock 	 * value and returning that up to our callers
982ea8dc4b6Seschrock 	 */
98343466aaeSMax Grossman 	dmu_buf_will_dirty(&db->db, tx);
984fa9e4066Sahrens 
985fa9e4066Sahrens 	/* create the data buffer for the new block */
986744947dcSTom Erickson 	buf = arc_buf_alloc(dn->dn_objset->os_spa, size, db, type);
987fa9e4066Sahrens 
988fa9e4066Sahrens 	/* copy old block data to the new block */
989fa9e4066Sahrens 	obuf = db->db_buf;
990f65e61c0Sahrens 	bcopy(obuf->b_data, buf->b_data, MIN(osize, size));
991fa9e4066Sahrens 	/* zero the remainder */
992f65e61c0Sahrens 	if (size > osize)
993f65e61c0Sahrens 		bzero((uint8_t *)buf->b_data + osize, size - osize);
994fa9e4066Sahrens 
995fa9e4066Sahrens 	mutex_enter(&db->db_mtx);
996fa9e4066Sahrens 	dbuf_set_data(db, buf);
9973b2aab18SMatthew Ahrens 	VERIFY(arc_buf_remove_ref(obuf, db));
998fa9e4066Sahrens 	db->db.db_size = size;
999fa9e4066Sahrens 
1000c717a561Smaybee 	if (db->db_level == 0) {
1001c717a561Smaybee 		ASSERT3U(db->db_last_dirty->dr_txg, ==, tx->tx_txg);
1002c717a561Smaybee 		db->db_last_dirty->dt.dl.dr_data = buf;
1003c717a561Smaybee 	}
1004fa9e4066Sahrens 	mutex_exit(&db->db_mtx);
1005fa9e4066Sahrens 
1006744947dcSTom Erickson 	dnode_willuse_space(dn, size-osize, tx);
1007744947dcSTom Erickson 	DB_DNODE_EXIT(db);
1008fa9e4066Sahrens }
1009fa9e4066Sahrens 
10103f9d6ad7SLin Ling void
10113f9d6ad7SLin Ling dbuf_release_bp(dmu_buf_impl_t *db)
10123f9d6ad7SLin Ling {
101343466aaeSMax Grossman 	objset_t *os = db->db_objset;
10143f9d6ad7SLin Ling 
10153f9d6ad7SLin Ling 	ASSERT(dsl_pool_sync_context(dmu_objset_pool(os)));
10163f9d6ad7SLin Ling 	ASSERT(arc_released(os->os_phys_buf) ||
10173f9d6ad7SLin Ling 	    list_link_active(&os->os_dsl_dataset->ds_synced_link));
10183f9d6ad7SLin Ling 	ASSERT(db->db_parent == NULL || arc_released(db->db_parent->db_buf));
10193f9d6ad7SLin Ling 
10201b912ec7SGeorge Wilson 	(void) arc_release(db->db_buf, db);
10213f9d6ad7SLin Ling }
10223f9d6ad7SLin Ling 
1023c717a561Smaybee dbuf_dirty_record_t *
1024fa9e4066Sahrens dbuf_dirty(dmu_buf_impl_t *db, dmu_tx_t *tx)
1025fa9e4066Sahrens {
1026744947dcSTom Erickson 	dnode_t *dn;
1027744947dcSTom Erickson 	objset_t *os;
1028c717a561Smaybee 	dbuf_dirty_record_t **drp, *dr;
1029fa9e4066Sahrens 	int drop_struct_lock = FALSE;
1030d3469faaSMark Maybee 	boolean_t do_free_accounting = B_FALSE;
1031fa9e4066Sahrens 	int txgoff = tx->tx_txg & TXG_MASK;
1032fa9e4066Sahrens 
1033fa9e4066Sahrens 	ASSERT(tx->tx_txg != 0);
1034fa9e4066Sahrens 	ASSERT(!refcount_is_zero(&db->db_holds));
10359c9dc39aSek 	DMU_TX_DIRTY_BUF(tx, db);
1036fa9e4066Sahrens 
1037744947dcSTom Erickson 	DB_DNODE_ENTER(db);
1038744947dcSTom Erickson 	dn = DB_DNODE(db);
1039fa9e4066Sahrens 	/*
1040fa9e4066Sahrens 	 * Shouldn't dirty a regular buffer in syncing context.  Private
1041fa9e4066Sahrens 	 * objects may be dirtied in syncing context, but only if they
1042fa9e4066Sahrens 	 * were already pre-dirtied in open context.
1043fa9e4066Sahrens 	 */
1044c717a561Smaybee 	ASSERT(!dmu_tx_is_syncing(tx) ||
1045c717a561Smaybee 	    BP_IS_HOLE(dn->dn_objset->os_rootbp) ||
104614843421SMatthew Ahrens 	    DMU_OBJECT_IS_SPECIAL(dn->dn_object) ||
104714843421SMatthew Ahrens 	    dn->dn_objset->os_dsl_dataset == NULL);
1048fa9e4066Sahrens 	/*
1049fa9e4066Sahrens 	 * We make this assert for private objects as well, but after we
1050fa9e4066Sahrens 	 * check if we're already dirty.  They are allowed to re-dirty
1051fa9e4066Sahrens 	 * in syncing context.
1052fa9e4066Sahrens 	 */
1053ea8dc4b6Seschrock 	ASSERT(dn->dn_object == DMU_META_DNODE_OBJECT ||
1054c717a561Smaybee 	    dn->dn_dirtyctx == DN_UNDIRTIED || dn->dn_dirtyctx ==
1055fa9e4066Sahrens 	    (dmu_tx_is_syncing(tx) ? DN_DIRTY_SYNC : DN_DIRTY_OPEN));
1056fa9e4066Sahrens 
1057fa9e4066Sahrens 	mutex_enter(&db->db_mtx);
1058fa9e4066Sahrens 	/*
1059c717a561Smaybee 	 * XXX make this true for indirects too?  The problem is that
1060c717a561Smaybee 	 * transactions created with dmu_tx_create_assigned() from
1061c717a561Smaybee 	 * syncing context don't bother holding ahead.
1062fa9e4066Sahrens 	 */
1063c717a561Smaybee 	ASSERT(db->db_level != 0 ||
106482c9918fSTim Haley 	    db->db_state == DB_CACHED || db->db_state == DB_FILL ||
106582c9918fSTim Haley 	    db->db_state == DB_NOFILL);
1066fa9e4066Sahrens 
1067fa9e4066Sahrens 	mutex_enter(&dn->dn_mtx);
1068fa9e4066Sahrens 	/*
1069fa9e4066Sahrens 	 * Don't set dirtyctx to SYNC if we're just modifying this as we
1070fa9e4066Sahrens 	 * initialize the objset.
1071fa9e4066Sahrens 	 */
1072fa9e4066Sahrens 	if (dn->dn_dirtyctx == DN_UNDIRTIED &&
1073c717a561Smaybee 	    !BP_IS_HOLE(dn->dn_objset->os_rootbp)) {
1074fa9e4066Sahrens 		dn->dn_dirtyctx =
1075fa9e4066Sahrens 		    (dmu_tx_is_syncing(tx) ? DN_DIRTY_SYNC : DN_DIRTY_OPEN);
1076fa9e4066Sahrens 		ASSERT(dn->dn_dirtyctx_firstset == NULL);
1077fa9e4066Sahrens 		dn->dn_dirtyctx_firstset = kmem_alloc(1, KM_SLEEP);
1078fa9e4066Sahrens 	}
1079fa9e4066Sahrens 	mutex_exit(&dn->dn_mtx);
1080fa9e4066Sahrens 
10810a586ceaSMark Shellenbaum 	if (db->db_blkid == DMU_SPILL_BLKID)
10820a586ceaSMark Shellenbaum 		dn->dn_have_spill = B_TRUE;
10830a586ceaSMark Shellenbaum 
1084fa9e4066Sahrens 	/*
1085fa9e4066Sahrens 	 * If this buffer is already dirty, we're done.
1086fa9e4066Sahrens 	 */
1087c717a561Smaybee 	drp = &db->db_last_dirty;
1088c717a561Smaybee 	ASSERT(*drp == NULL || (*drp)->dr_txg <= tx->tx_txg ||
1089c717a561Smaybee 	    db->db.db_object == DMU_META_DNODE_OBJECT);
10907e2186e3Sbonwick 	while ((dr = *drp) != NULL && dr->dr_txg > tx->tx_txg)
10917e2186e3Sbonwick 		drp = &dr->dr_next;
10927e2186e3Sbonwick 	if (dr && dr->dr_txg == tx->tx_txg) {
1093744947dcSTom Erickson 		DB_DNODE_EXIT(db);
1094744947dcSTom Erickson 
10950a586ceaSMark Shellenbaum 		if (db->db_level == 0 && db->db_blkid != DMU_BONUS_BLKID) {
1096c717a561Smaybee 			/*
1097c717a561Smaybee 			 * If this buffer has already been written out,
1098c717a561Smaybee 			 * we now need to reset its state.
1099c717a561Smaybee 			 */
11007e2186e3Sbonwick 			dbuf_unoverride(dr);
1101b24ab676SJeff Bonwick 			if (db->db.db_object != DMU_META_DNODE_OBJECT &&
1102b24ab676SJeff Bonwick 			    db->db_state != DB_NOFILL)
1103c717a561Smaybee 				arc_buf_thaw(db->db_buf);
1104c717a561Smaybee 		}
1105fa9e4066Sahrens 		mutex_exit(&db->db_mtx);
11067e2186e3Sbonwick 		return (dr);
1107fa9e4066Sahrens 	}
1108fa9e4066Sahrens 
1109fa9e4066Sahrens 	/*
1110fa9e4066Sahrens 	 * Only valid if not already dirty.
1111fa9e4066Sahrens 	 */
111214843421SMatthew Ahrens 	ASSERT(dn->dn_object == 0 ||
111314843421SMatthew Ahrens 	    dn->dn_dirtyctx == DN_UNDIRTIED || dn->dn_dirtyctx ==
1114fa9e4066Sahrens 	    (dmu_tx_is_syncing(tx) ? DN_DIRTY_SYNC : DN_DIRTY_OPEN));
1115fa9e4066Sahrens 
1116fa9e4066Sahrens 	ASSERT3U(dn->dn_nlevels, >, db->db_level);
1117fa9e4066Sahrens 	ASSERT((dn->dn_phys->dn_nlevels == 0 && db->db_level == 0) ||
1118fa9e4066Sahrens 	    dn->dn_phys->dn_nlevels > db->db_level ||
1119fa9e4066Sahrens 	    dn->dn_next_nlevels[txgoff] > db->db_level ||
1120fa9e4066Sahrens 	    dn->dn_next_nlevels[(tx->tx_txg-1) & TXG_MASK] > db->db_level ||
1121fa9e4066Sahrens 	    dn->dn_next_nlevels[(tx->tx_txg-2) & TXG_MASK] > db->db_level);
1122fa9e4066Sahrens 
1123fa9e4066Sahrens 	/*
1124fa9e4066Sahrens 	 * We should only be dirtying in syncing context if it's the
112514843421SMatthew Ahrens 	 * mos or we're initializing the os or it's a special object.
112614843421SMatthew Ahrens 	 * However, we are allowed to dirty in syncing context provided
112714843421SMatthew Ahrens 	 * we already dirtied it in open context.  Hence we must make
112814843421SMatthew Ahrens 	 * this assertion only if we're not already dirty.
1129fa9e4066Sahrens 	 */
1130744947dcSTom Erickson 	os = dn->dn_objset;
113114843421SMatthew Ahrens 	ASSERT(!dmu_tx_is_syncing(tx) || DMU_OBJECT_IS_SPECIAL(dn->dn_object) ||
113214843421SMatthew Ahrens 	    os->os_dsl_dataset == NULL || BP_IS_HOLE(os->os_rootbp));
1133fa9e4066Sahrens 	ASSERT(db->db.db_size != 0);
1134fa9e4066Sahrens 
1135fa9e4066Sahrens 	dprintf_dbuf(db, "size=%llx\n", (u_longlong_t)db->db.db_size);
1136fa9e4066Sahrens 
11370a586ceaSMark Shellenbaum 	if (db->db_blkid != DMU_BONUS_BLKID) {
11381934e92fSmaybee 		/*
11391934e92fSmaybee 		 * Update the accounting.
1140d3469faaSMark Maybee 		 * Note: we delay "free accounting" until after we drop
1141d3469faaSMark Maybee 		 * the db_mtx.  This keeps us from grabbing other locks
1142b24ab676SJeff Bonwick 		 * (and possibly deadlocking) in bp_get_dsize() while
1143d3469faaSMark Maybee 		 * also holding the db_mtx.
11441934e92fSmaybee 		 */
11451934e92fSmaybee 		dnode_willuse_space(dn, db->db.db_size, tx);
1146d3469faaSMark Maybee 		do_free_accounting = dbuf_block_freeable(db);
11471934e92fSmaybee 	}
11481934e92fSmaybee 
1149ea8dc4b6Seschrock 	/*
1150ea8dc4b6Seschrock 	 * If this buffer is dirty in an old transaction group we need
1151ea8dc4b6Seschrock 	 * to make a copy of it so that the changes we make in this
1152ea8dc4b6Seschrock 	 * transaction group won't leak out when we sync the older txg.
1153ea8dc4b6Seschrock 	 */
1154c717a561Smaybee 	dr = kmem_zalloc(sizeof (dbuf_dirty_record_t), KM_SLEEP);
1155c717a561Smaybee 	if (db->db_level == 0) {
1156c717a561Smaybee 		void *data_old = db->db_buf;
1157c717a561Smaybee 
115882c9918fSTim Haley 		if (db->db_state != DB_NOFILL) {
11590a586ceaSMark Shellenbaum 			if (db->db_blkid == DMU_BONUS_BLKID) {
116082c9918fSTim Haley 				dbuf_fix_old_data(db, tx->tx_txg);
116182c9918fSTim Haley 				data_old = db->db.db_data;
116282c9918fSTim Haley 			} else if (db->db.db_object != DMU_META_DNODE_OBJECT) {
116382c9918fSTim Haley 				/*
116482c9918fSTim Haley 				 * Release the data buffer from the cache so
116582c9918fSTim Haley 				 * that we can modify it without impacting
116682c9918fSTim Haley 				 * possible other users of this cached data
116782c9918fSTim Haley 				 * block.  Note that indirect blocks and
116882c9918fSTim Haley 				 * private objects are not released until the
116982c9918fSTim Haley 				 * syncing state (since they are only modified
117082c9918fSTim Haley 				 * then).
117182c9918fSTim Haley 				 */
117282c9918fSTim Haley 				arc_release(db->db_buf, db);
117382c9918fSTim Haley 				dbuf_fix_old_data(db, tx->tx_txg);
117482c9918fSTim Haley 				data_old = db->db_buf;
117582c9918fSTim Haley 			}
117682c9918fSTim Haley 			ASSERT(data_old != NULL);
1177fa9e4066Sahrens 		}
1178c717a561Smaybee 		dr->dt.dl.dr_data = data_old;
1179c717a561Smaybee 	} else {
1180c717a561Smaybee 		mutex_init(&dr->dt.di.dr_mtx, NULL, MUTEX_DEFAULT, NULL);
1181c717a561Smaybee 		list_create(&dr->dt.di.dr_children,
1182c717a561Smaybee 		    sizeof (dbuf_dirty_record_t),
1183c717a561Smaybee 		    offsetof(dbuf_dirty_record_t, dr_dirty_node));
1184fa9e4066Sahrens 	}
118569962b56SMatthew Ahrens 	if (db->db_blkid != DMU_BONUS_BLKID && os->os_dsl_dataset != NULL)
118669962b56SMatthew Ahrens 		dr->dr_accounted = db->db.db_size;
1187c717a561Smaybee 	dr->dr_dbuf = db;
1188c717a561Smaybee 	dr->dr_txg = tx->tx_txg;
1189c717a561Smaybee 	dr->dr_next = *drp;
1190c717a561Smaybee 	*drp = dr;
1191fa9e4066Sahrens 
1192fa9e4066Sahrens 	/*
1193fa9e4066Sahrens 	 * We could have been freed_in_flight between the dbuf_noread
1194fa9e4066Sahrens 	 * and dbuf_dirty.  We win, as though the dbuf_noread() had
1195fa9e4066Sahrens 	 * happened after the free.
1196fa9e4066Sahrens 	 */
11970a586ceaSMark Shellenbaum 	if (db->db_level == 0 && db->db_blkid != DMU_BONUS_BLKID &&
11980a586ceaSMark Shellenbaum 	    db->db_blkid != DMU_SPILL_BLKID) {
1199c717a561Smaybee 		mutex_enter(&dn->dn_mtx);
1200bf16b11eSMatthew Ahrens 		if (dn->dn_free_ranges[txgoff] != NULL) {
1201bf16b11eSMatthew Ahrens 			range_tree_clear(dn->dn_free_ranges[txgoff],
1202bf16b11eSMatthew Ahrens 			    db->db_blkid, 1);
1203bf16b11eSMatthew Ahrens 		}
1204c717a561Smaybee 		mutex_exit(&dn->dn_mtx);
1205c717a561Smaybee 		db->db_freed_in_flight = FALSE;
1206fa9e4066Sahrens 	}
1207fa9e4066Sahrens 
1208fa9e4066Sahrens 	/*
1209fa9e4066Sahrens 	 * This buffer is now part of this txg
1210fa9e4066Sahrens 	 */
1211fa9e4066Sahrens 	dbuf_add_ref(db, (void *)(uintptr_t)tx->tx_txg);
1212fa9e4066Sahrens 	db->db_dirtycnt += 1;
1213fa9e4066Sahrens 	ASSERT3U(db->db_dirtycnt, <=, 3);
1214fa9e4066Sahrens 
1215fa9e4066Sahrens 	mutex_exit(&db->db_mtx);
1216fa9e4066Sahrens 
12170a586ceaSMark Shellenbaum 	if (db->db_blkid == DMU_BONUS_BLKID ||
12180a586ceaSMark Shellenbaum 	    db->db_blkid == DMU_SPILL_BLKID) {
1219c717a561Smaybee 		mutex_enter(&dn->dn_mtx);
1220c717a561Smaybee 		ASSERT(!list_link_active(&dr->dr_dirty_node));
1221c717a561Smaybee 		list_insert_tail(&dn->dn_dirty_records[txgoff], dr);
1222c717a561Smaybee 		mutex_exit(&dn->dn_mtx);
1223fa9e4066Sahrens 		dnode_setdirty(dn, tx);
1224744947dcSTom Erickson 		DB_DNODE_EXIT(db);
1225c717a561Smaybee 		return (dr);
1226d3469faaSMark Maybee 	} else if (do_free_accounting) {
1227d3469faaSMark Maybee 		blkptr_t *bp = db->db_blkptr;
1228d3469faaSMark Maybee 		int64_t willfree = (bp && !BP_IS_HOLE(bp)) ?
1229b24ab676SJeff Bonwick 		    bp_get_dsize(os->os_spa, bp) : db->db.db_size;
1230d3469faaSMark Maybee 		/*
1231d3469faaSMark Maybee 		 * This is only a guess -- if the dbuf is dirty
1232d3469faaSMark Maybee 		 * in a previous txg, we don't know how much
1233d3469faaSMark Maybee 		 * space it will use on disk yet.  We should
1234d3469faaSMark Maybee 		 * really have the struct_rwlock to access
1235d3469faaSMark Maybee 		 * db_blkptr, but since this is just a guess,
1236d3469faaSMark Maybee 		 * it's OK if we get an odd answer.
1237d3469faaSMark Maybee 		 */
1238837b568bSGeorge Wilson 		ddt_prefetch(os->os_spa, bp);
1239d3469faaSMark Maybee 		dnode_willuse_space(dn, -willfree, tx);
1240fa9e4066Sahrens 	}
1241fa9e4066Sahrens 
1242fa9e4066Sahrens 	if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) {
1243fa9e4066Sahrens 		rw_enter(&dn->dn_struct_rwlock, RW_READER);
1244fa9e4066Sahrens 		drop_struct_lock = TRUE;
1245fa9e4066Sahrens 	}
1246fa9e4066Sahrens 
12478346f03fSJonathan W Adams 	if (db->db_level == 0) {
12488346f03fSJonathan W Adams 		dnode_new_blkid(dn, db->db_blkid, tx, drop_struct_lock);
12498346f03fSJonathan W Adams 		ASSERT(dn->dn_maxblkid >= db->db_blkid);
12508346f03fSJonathan W Adams 	}
12518346f03fSJonathan W Adams 
125244eda4d7Smaybee 	if (db->db_level+1 < dn->dn_nlevels) {
1253c717a561Smaybee 		dmu_buf_impl_t *parent = db->db_parent;
1254c717a561Smaybee 		dbuf_dirty_record_t *di;
1255c717a561Smaybee 		int parent_held = FALSE;
1256c717a561Smaybee 
1257c717a561Smaybee 		if (db->db_parent == NULL || db->db_parent == dn->dn_dbuf) {
1258c717a561Smaybee 			int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
1259c717a561Smaybee 
1260c717a561Smaybee 			parent = dbuf_hold_level(dn, db->db_level+1,
1261c717a561Smaybee 			    db->db_blkid >> epbs, FTAG);
126201025c89SJohn Harres 			ASSERT(parent != NULL);
1263c717a561Smaybee 			parent_held = TRUE;
1264c717a561Smaybee 		}
1265fa9e4066Sahrens 		if (drop_struct_lock)
1266fa9e4066Sahrens 			rw_exit(&dn->dn_struct_rwlock);
1267c717a561Smaybee 		ASSERT3U(db->db_level+1, ==, parent->db_level);
1268c717a561Smaybee 		di = dbuf_dirty(parent, tx);
1269c717a561Smaybee 		if (parent_held)
1270c717a561Smaybee 			dbuf_rele(parent, FTAG);
1271c717a561Smaybee 
1272c717a561Smaybee 		mutex_enter(&db->db_mtx);
127369962b56SMatthew Ahrens 		/*
127469962b56SMatthew Ahrens 		 * Since we've dropped the mutex, it's possible that
127569962b56SMatthew Ahrens 		 * dbuf_undirty() might have changed this out from under us.
127669962b56SMatthew Ahrens 		 */
1277c717a561Smaybee 		if (db->db_last_dirty == dr ||
1278c717a561Smaybee 		    dn->dn_object == DMU_META_DNODE_OBJECT) {
1279c717a561Smaybee 			mutex_enter(&di->dt.di.dr_mtx);
1280c717a561Smaybee 			ASSERT3U(di->dr_txg, ==, tx->tx_txg);
1281c717a561Smaybee 			ASSERT(!list_link_active(&dr->dr_dirty_node));
1282c717a561Smaybee 			list_insert_tail(&di->dt.di.dr_children, dr);
1283c717a561Smaybee 			mutex_exit(&di->dt.di.dr_mtx);
1284c717a561Smaybee 			dr->dr_parent = di;
1285c717a561Smaybee 		}
1286c717a561Smaybee 		mutex_exit(&db->db_mtx);
1287fa9e4066Sahrens 	} else {
1288c717a561Smaybee 		ASSERT(db->db_level+1 == dn->dn_nlevels);
1289c717a561Smaybee 		ASSERT(db->db_blkid < dn->dn_nblkptr);
1290744947dcSTom Erickson 		ASSERT(db->db_parent == NULL || db->db_parent == dn->dn_dbuf);
1291c717a561Smaybee 		mutex_enter(&dn->dn_mtx);
1292c717a561Smaybee 		ASSERT(!list_link_active(&dr->dr_dirty_node));
1293c717a561Smaybee 		list_insert_tail(&dn->dn_dirty_records[txgoff], dr);
1294c717a561Smaybee 		mutex_exit(&dn->dn_mtx);
1295fa9e4066Sahrens 		if (drop_struct_lock)
1296fa9e4066Sahrens 			rw_exit(&dn->dn_struct_rwlock);
1297fa9e4066Sahrens 	}
1298fa9e4066Sahrens 
1299fa9e4066Sahrens 	dnode_setdirty(dn, tx);
1300744947dcSTom Erickson 	DB_DNODE_EXIT(db);
1301c717a561Smaybee 	return (dr);
1302fa9e4066Sahrens }
1303fa9e4066Sahrens 
13043b2aab18SMatthew Ahrens /*
13053e30c24aSWill Andrews  * Undirty a buffer in the transaction group referenced by the given
13063e30c24aSWill Andrews  * transaction.  Return whether this evicted the dbuf.
13073b2aab18SMatthew Ahrens  */
13083b2aab18SMatthew Ahrens static boolean_t
1309fa9e4066Sahrens dbuf_undirty(dmu_buf_impl_t *db, dmu_tx_t *tx)
1310fa9e4066Sahrens {
1311744947dcSTom Erickson 	dnode_t *dn;
1312c717a561Smaybee 	uint64_t txg = tx->tx_txg;
131317f17c2dSbonwick 	dbuf_dirty_record_t *dr, **drp;
1314fa9e4066Sahrens 
1315c717a561Smaybee 	ASSERT(txg != 0);
13160a586ceaSMark Shellenbaum 	ASSERT(db->db_blkid != DMU_BONUS_BLKID);
13173b2aab18SMatthew Ahrens 	ASSERT0(db->db_level);
13183b2aab18SMatthew Ahrens 	ASSERT(MUTEX_HELD(&db->db_mtx));
1319fa9e4066Sahrens 
1320fa9e4066Sahrens 	/*
1321fa9e4066Sahrens 	 * If this buffer is not dirty, we're done.
1322fa9e4066Sahrens 	 */
132317f17c2dSbonwick 	for (drp = &db->db_last_dirty; (dr = *drp) != NULL; drp = &dr->dr_next)
1324c717a561Smaybee 		if (dr->dr_txg <= txg)
1325c717a561Smaybee 			break;
13263b2aab18SMatthew Ahrens 	if (dr == NULL || dr->dr_txg < txg)
13273b2aab18SMatthew Ahrens 		return (B_FALSE);
1328c717a561Smaybee 	ASSERT(dr->dr_txg == txg);
1329b24ab676SJeff Bonwick 	ASSERT(dr->dr_dbuf == db);
1330fa9e4066Sahrens 
1331744947dcSTom Erickson 	DB_DNODE_ENTER(db);
1332744947dcSTom Erickson 	dn = DB_DNODE(db);
1333744947dcSTom Erickson 
1334fa9e4066Sahrens 	dprintf_dbuf(db, "size=%llx\n", (u_longlong_t)db->db.db_size);
1335fa9e4066Sahrens 
1336fa9e4066Sahrens 	ASSERT(db->db.db_size != 0);
1337fa9e4066Sahrens 
133869962b56SMatthew Ahrens 	/*
133969962b56SMatthew Ahrens 	 * Any space we accounted for in dp_dirty_* will be cleaned up by
134069962b56SMatthew Ahrens 	 * dsl_pool_sync().  This is relatively rare so the discrepancy
134169962b56SMatthew Ahrens 	 * is not a big deal.
134269962b56SMatthew Ahrens 	 */
1343fa9e4066Sahrens 
134417f17c2dSbonwick 	*drp = dr->dr_next;
1345c717a561Smaybee 
13463f2366c2SGordon Ross 	/*
13473f2366c2SGordon Ross 	 * Note that there are three places in dbuf_dirty()
13483f2366c2SGordon Ross 	 * where this dirty record may be put on a list.
13493f2366c2SGordon Ross 	 * Make sure to do a list_remove corresponding to
13503f2366c2SGordon Ross 	 * every one of those list_insert calls.
13513f2366c2SGordon Ross 	 */
1352c717a561Smaybee 	if (dr->dr_parent) {
1353c717a561Smaybee 		mutex_enter(&dr->dr_parent->dt.di.dr_mtx);
1354c717a561Smaybee 		list_remove(&dr->dr_parent->dt.di.dr_children, dr);
1355c717a561Smaybee 		mutex_exit(&dr->dr_parent->dt.di.dr_mtx);
13563f2366c2SGordon Ross 	} else if (db->db_blkid == DMU_SPILL_BLKID ||
13573f2366c2SGordon Ross 	    db->db_level+1 == dn->dn_nlevels) {
1358cdb0ab79Smaybee 		ASSERT(db->db_blkptr == NULL || db->db_parent == dn->dn_dbuf);
1359c717a561Smaybee 		mutex_enter(&dn->dn_mtx);
1360c717a561Smaybee 		list_remove(&dn->dn_dirty_records[txg & TXG_MASK], dr);
1361c717a561Smaybee 		mutex_exit(&dn->dn_mtx);
1362c717a561Smaybee 	}
1363744947dcSTom Erickson 	DB_DNODE_EXIT(db);
1364c717a561Smaybee 
13653b2aab18SMatthew Ahrens 	if (db->db_state != DB_NOFILL) {
13663b2aab18SMatthew Ahrens 		dbuf_unoverride(dr);
1367c717a561Smaybee 
1368c717a561Smaybee 		ASSERT(db->db_buf != NULL);
13693b2aab18SMatthew Ahrens 		ASSERT(dr->dt.dl.dr_data != NULL);
13703b2aab18SMatthew Ahrens 		if (dr->dt.dl.dr_data != db->db_buf)
13713b2aab18SMatthew Ahrens 			VERIFY(arc_buf_remove_ref(dr->dt.dl.dr_data, db));
1372c717a561Smaybee 	}
1373d2b3cbbdSJorgen Lundman 
1374d2b3cbbdSJorgen Lundman 	if (db->db_level != 0) {
1375d2b3cbbdSJorgen Lundman 		mutex_destroy(&dr->dt.di.dr_mtx);
1376d2b3cbbdSJorgen Lundman 		list_destroy(&dr->dt.di.dr_children);
1377d2b3cbbdSJorgen Lundman 	}
1378d2b3cbbdSJorgen Lundman 
1379c717a561Smaybee 	kmem_free(dr, sizeof (dbuf_dirty_record_t));
1380fa9e4066Sahrens 
1381fa9e4066Sahrens 	ASSERT(db->db_dirtycnt > 0);
1382fa9e4066Sahrens 	db->db_dirtycnt -= 1;
1383fa9e4066Sahrens 
1384c717a561Smaybee 	if (refcount_remove(&db->db_holds, (void *)(uintptr_t)txg) == 0) {
1385ea8dc4b6Seschrock 		arc_buf_t *buf = db->db_buf;
1386fa9e4066Sahrens 
1387b24ab676SJeff Bonwick 		ASSERT(db->db_state == DB_NOFILL || arc_released(buf));
1388ea8dc4b6Seschrock 		dbuf_set_data(db, NULL);
13893b2aab18SMatthew Ahrens 		VERIFY(arc_buf_remove_ref(buf, db));
1390fa9e4066Sahrens 		dbuf_evict(db);
13913b2aab18SMatthew Ahrens 		return (B_TRUE);
1392fa9e4066Sahrens 	}
1393fa9e4066Sahrens 
13943b2aab18SMatthew Ahrens 	return (B_FALSE);
1395fa9e4066Sahrens }
1396fa9e4066Sahrens 
1397fa9e4066Sahrens void
139843466aaeSMax Grossman dmu_buf_will_dirty(dmu_buf_t *db_fake, dmu_tx_t *tx)
1399fa9e4066Sahrens {
140043466aaeSMax Grossman 	dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
14011ab7f2deSmaybee 	int rf = DB_RF_MUST_SUCCEED | DB_RF_NOPREFETCH;
1402fa9e4066Sahrens 
1403fa9e4066Sahrens 	ASSERT(tx->tx_txg != 0);
1404fa9e4066Sahrens 	ASSERT(!refcount_is_zero(&db->db_holds));
1405fa9e4066Sahrens 
1406744947dcSTom Erickson 	DB_DNODE_ENTER(db);
1407744947dcSTom Erickson 	if (RW_WRITE_HELD(&DB_DNODE(db)->dn_struct_rwlock))
1408fa9e4066Sahrens 		rf |= DB_RF_HAVESTRUCT;
1409744947dcSTom Erickson 	DB_DNODE_EXIT(db);
1410ea8dc4b6Seschrock 	(void) dbuf_read(db, NULL, rf);
1411c717a561Smaybee 	(void) dbuf_dirty(db, tx);
1412fa9e4066Sahrens }
1413fa9e4066Sahrens 
141482c9918fSTim Haley void
141582c9918fSTim Haley dmu_buf_will_not_fill(dmu_buf_t *db_fake, dmu_tx_t *tx)
141682c9918fSTim Haley {
141782c9918fSTim Haley 	dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
141882c9918fSTim Haley 
141982c9918fSTim Haley 	db->db_state = DB_NOFILL;
142082c9918fSTim Haley 
142182c9918fSTim Haley 	dmu_buf_will_fill(db_fake, tx);
142282c9918fSTim Haley }
142382c9918fSTim Haley 
1424fa9e4066Sahrens void
1425ea8dc4b6Seschrock dmu_buf_will_fill(dmu_buf_t *db_fake, dmu_tx_t *tx)
1426fa9e4066Sahrens {
1427ea8dc4b6Seschrock 	dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
1428ea8dc4b6Seschrock 
14290a586ceaSMark Shellenbaum 	ASSERT(db->db_blkid != DMU_BONUS_BLKID);
1430fa9e4066Sahrens 	ASSERT(tx->tx_txg != 0);
1431fa9e4066Sahrens 	ASSERT(db->db_level == 0);
1432fa9e4066Sahrens 	ASSERT(!refcount_is_zero(&db->db_holds));
1433fa9e4066Sahrens 
1434ea8dc4b6Seschrock 	ASSERT(db->db.db_object != DMU_META_DNODE_OBJECT ||
1435fa9e4066Sahrens 	    dmu_tx_private_ok(tx));
1436fa9e4066Sahrens 
1437fa9e4066Sahrens 	dbuf_noread(db);
1438c717a561Smaybee 	(void) dbuf_dirty(db, tx);
1439fa9e4066Sahrens }
1440fa9e4066Sahrens 
1441fa9e4066Sahrens #pragma weak dmu_buf_fill_done = dbuf_fill_done
1442fa9e4066Sahrens /* ARGSUSED */
1443fa9e4066Sahrens void
1444fa9e4066Sahrens dbuf_fill_done(dmu_buf_impl_t *db, dmu_tx_t *tx)
1445fa9e4066Sahrens {
1446fa9e4066Sahrens 	mutex_enter(&db->db_mtx);
14479c9dc39aSek 	DBUF_VERIFY(db);
1448fa9e4066Sahrens 
1449fa9e4066Sahrens 	if (db->db_state == DB_FILL) {
1450c717a561Smaybee 		if (db->db_level == 0 && db->db_freed_in_flight) {
14510a586ceaSMark Shellenbaum 			ASSERT(db->db_blkid != DMU_BONUS_BLKID);
1452fa9e4066Sahrens 			/* we were freed while filling */
1453fa9e4066Sahrens 			/* XXX dbuf_undirty? */
1454fa9e4066Sahrens 			bzero(db->db.db_data, db->db.db_size);
1455c717a561Smaybee 			db->db_freed_in_flight = FALSE;
1456fa9e4066Sahrens 		}
1457fa9e4066Sahrens 		db->db_state = DB_CACHED;
1458fa9e4066Sahrens 		cv_broadcast(&db->db_changed);
1459fa9e4066Sahrens 	}
1460fa9e4066Sahrens 	mutex_exit(&db->db_mtx);
1461fa9e4066Sahrens }
1462fa9e4066Sahrens 
14635d7b4d43SMatthew Ahrens void
14645d7b4d43SMatthew Ahrens dmu_buf_write_embedded(dmu_buf_t *dbuf, void *data,
14655d7b4d43SMatthew Ahrens     bp_embedded_type_t etype, enum zio_compress comp,
14665d7b4d43SMatthew Ahrens     int uncompressed_size, int compressed_size, int byteorder,
14675d7b4d43SMatthew Ahrens     dmu_tx_t *tx)
14685d7b4d43SMatthew Ahrens {
14695d7b4d43SMatthew Ahrens 	dmu_buf_impl_t *db = (dmu_buf_impl_t *)dbuf;
14705d7b4d43SMatthew Ahrens 	struct dirty_leaf *dl;
14715d7b4d43SMatthew Ahrens 	dmu_object_type_t type;
14725d7b4d43SMatthew Ahrens 
14735d7b4d43SMatthew Ahrens 	DB_DNODE_ENTER(db);
14745d7b4d43SMatthew Ahrens 	type = DB_DNODE(db)->dn_type;
14755d7b4d43SMatthew Ahrens 	DB_DNODE_EXIT(db);
14765d7b4d43SMatthew Ahrens 
14775d7b4d43SMatthew Ahrens 	ASSERT0(db->db_level);
14785d7b4d43SMatthew Ahrens 	ASSERT(db->db_blkid != DMU_BONUS_BLKID);
14795d7b4d43SMatthew Ahrens 
14805d7b4d43SMatthew Ahrens 	dmu_buf_will_not_fill(dbuf, tx);
14815d7b4d43SMatthew Ahrens 
14825d7b4d43SMatthew Ahrens 	ASSERT3U(db->db_last_dirty->dr_txg, ==, tx->tx_txg);
14835d7b4d43SMatthew Ahrens 	dl = &db->db_last_dirty->dt.dl;
14845d7b4d43SMatthew Ahrens 	encode_embedded_bp_compressed(&dl->dr_overridden_by,
14855d7b4d43SMatthew Ahrens 	    data, comp, uncompressed_size, compressed_size);
14865d7b4d43SMatthew Ahrens 	BPE_SET_ETYPE(&dl->dr_overridden_by, etype);
14875d7b4d43SMatthew Ahrens 	BP_SET_TYPE(&dl->dr_overridden_by, type);
14885d7b4d43SMatthew Ahrens 	BP_SET_LEVEL(&dl->dr_overridden_by, 0);
14895d7b4d43SMatthew Ahrens 	BP_SET_BYTEORDER(&dl->dr_overridden_by, byteorder);
14905d7b4d43SMatthew Ahrens 
14915d7b4d43SMatthew Ahrens 	dl->dr_override_state = DR_OVERRIDDEN;
14925d7b4d43SMatthew Ahrens 	dl->dr_overridden_by.blk_birth = db->db_last_dirty->dr_txg;
14935d7b4d43SMatthew Ahrens }
14945d7b4d43SMatthew Ahrens 
14952fdbea25SAleksandr Guzovskiy /*
14962fdbea25SAleksandr Guzovskiy  * Directly assign a provided arc buf to a given dbuf if it's not referenced
14972fdbea25SAleksandr Guzovskiy  * by anybody except our caller. Otherwise copy arcbuf's contents to dbuf.
14982fdbea25SAleksandr Guzovskiy  */
14992fdbea25SAleksandr Guzovskiy void
15002fdbea25SAleksandr Guzovskiy dbuf_assign_arcbuf(dmu_buf_impl_t *db, arc_buf_t *buf, dmu_tx_t *tx)
15012fdbea25SAleksandr Guzovskiy {
15022fdbea25SAleksandr Guzovskiy 	ASSERT(!refcount_is_zero(&db->db_holds));
15030a586ceaSMark Shellenbaum 	ASSERT(db->db_blkid != DMU_BONUS_BLKID);
15042fdbea25SAleksandr Guzovskiy 	ASSERT(db->db_level == 0);
15052fdbea25SAleksandr Guzovskiy 	ASSERT(DBUF_GET_BUFC_TYPE(db) == ARC_BUFC_DATA);
15062fdbea25SAleksandr Guzovskiy 	ASSERT(buf != NULL);
15072fdbea25SAleksandr Guzovskiy 	ASSERT(arc_buf_size(buf) == db->db.db_size);
15082fdbea25SAleksandr Guzovskiy 	ASSERT(tx->tx_txg != 0);
15092fdbea25SAleksandr Guzovskiy 
15102fdbea25SAleksandr Guzovskiy 	arc_return_buf(buf, db);
15112fdbea25SAleksandr Guzovskiy 	ASSERT(arc_released(buf));
15122fdbea25SAleksandr Guzovskiy 
15132fdbea25SAleksandr Guzovskiy 	mutex_enter(&db->db_mtx);
15142fdbea25SAleksandr Guzovskiy 
15152fdbea25SAleksandr Guzovskiy 	while (db->db_state == DB_READ || db->db_state == DB_FILL)
15162fdbea25SAleksandr Guzovskiy 		cv_wait(&db->db_changed, &db->db_mtx);
15172fdbea25SAleksandr Guzovskiy 
15182fdbea25SAleksandr Guzovskiy 	ASSERT(db->db_state == DB_CACHED || db->db_state == DB_UNCACHED);
15192fdbea25SAleksandr Guzovskiy 
15202fdbea25SAleksandr Guzovskiy 	if (db->db_state == DB_CACHED &&
15212fdbea25SAleksandr Guzovskiy 	    refcount_count(&db->db_holds) - 1 > db->db_dirtycnt) {
15222fdbea25SAleksandr Guzovskiy 		mutex_exit(&db->db_mtx);
15232fdbea25SAleksandr Guzovskiy 		(void) dbuf_dirty(db, tx);
15242fdbea25SAleksandr Guzovskiy 		bcopy(buf->b_data, db->db.db_data, db->db.db_size);
15253b2aab18SMatthew Ahrens 		VERIFY(arc_buf_remove_ref(buf, db));
1526c242f9a0Schunli zhang - Sun Microsystems - Irvine United States 		xuio_stat_wbuf_copied();
15272fdbea25SAleksandr Guzovskiy 		return;
15282fdbea25SAleksandr Guzovskiy 	}
15292fdbea25SAleksandr Guzovskiy 
1530c242f9a0Schunli zhang - Sun Microsystems - Irvine United States 	xuio_stat_wbuf_nocopy();
15312fdbea25SAleksandr Guzovskiy 	if (db->db_state == DB_CACHED) {
15322fdbea25SAleksandr Guzovskiy 		dbuf_dirty_record_t *dr = db->db_last_dirty;
15332fdbea25SAleksandr Guzovskiy 
15342fdbea25SAleksandr Guzovskiy 		ASSERT(db->db_buf != NULL);
15352fdbea25SAleksandr Guzovskiy 		if (dr != NULL && dr->dr_txg == tx->tx_txg) {
15362fdbea25SAleksandr Guzovskiy 			ASSERT(dr->dt.dl.dr_data == db->db_buf);
15372fdbea25SAleksandr Guzovskiy 			if (!arc_released(db->db_buf)) {
15382fdbea25SAleksandr Guzovskiy 				ASSERT(dr->dt.dl.dr_override_state ==
15392fdbea25SAleksandr Guzovskiy 				    DR_OVERRIDDEN);
15402fdbea25SAleksandr Guzovskiy 				arc_release(db->db_buf, db);
15412fdbea25SAleksandr Guzovskiy 			}
15422fdbea25SAleksandr Guzovskiy 			dr->dt.dl.dr_data = buf;
15433b2aab18SMatthew Ahrens 			VERIFY(arc_buf_remove_ref(db->db_buf, db));
15442fdbea25SAleksandr Guzovskiy 		} else if (dr == NULL || dr->dt.dl.dr_data != db->db_buf) {
15452fdbea25SAleksandr Guzovskiy 			arc_release(db->db_buf, db);
15463b2aab18SMatthew Ahrens 			VERIFY(arc_buf_remove_ref(db->db_buf, db));
15472fdbea25SAleksandr Guzovskiy 		}
15482fdbea25SAleksandr Guzovskiy 		db->db_buf = NULL;
15492fdbea25SAleksandr Guzovskiy 	}
15502fdbea25SAleksandr Guzovskiy 	ASSERT(db->db_buf == NULL);
15512fdbea25SAleksandr Guzovskiy 	dbuf_set_data(db, buf);
15522fdbea25SAleksandr Guzovskiy 	db->db_state = DB_FILL;
15532fdbea25SAleksandr Guzovskiy 	mutex_exit(&db->db_mtx);
15542fdbea25SAleksandr Guzovskiy 	(void) dbuf_dirty(db, tx);
155543466aaeSMax Grossman 	dmu_buf_fill_done(&db->db, tx);
15562fdbea25SAleksandr Guzovskiy }
15572fdbea25SAleksandr Guzovskiy 
1558ea8dc4b6Seschrock /*
1559ea8dc4b6Seschrock  * "Clear" the contents of this dbuf.  This will mark the dbuf
156069962b56SMatthew Ahrens  * EVICTING and clear *most* of its references.  Unfortunately,
1561ea8dc4b6Seschrock  * when we are not holding the dn_dbufs_mtx, we can't clear the
1562ea8dc4b6Seschrock  * entry in the dn_dbufs list.  We have to wait until dbuf_destroy()
1563ea8dc4b6Seschrock  * in this case.  For callers from the DMU we will usually see:
1564bbfa8ea8SMatthew Ahrens  *	dbuf_clear()->arc_clear_callback()->dbuf_do_evict()->dbuf_destroy()
1565ea8dc4b6Seschrock  * For the arc callback, we will usually see:
1566744947dcSTom Erickson  *	dbuf_do_evict()->dbuf_clear();dbuf_destroy()
1567ea8dc4b6Seschrock  * Sometimes, though, we will get a mix of these two:
1568bbfa8ea8SMatthew Ahrens  *	DMU: dbuf_clear()->arc_clear_callback()
1569ea8dc4b6Seschrock  *	ARC: dbuf_do_evict()->dbuf_destroy()
1570bbfa8ea8SMatthew Ahrens  *
1571bbfa8ea8SMatthew Ahrens  * This routine will dissociate the dbuf from the arc, by calling
1572bbfa8ea8SMatthew Ahrens  * arc_clear_callback(), but will not evict the data from the ARC.
1573ea8dc4b6Seschrock  */
1574ea8dc4b6Seschrock void
1575fa9e4066Sahrens dbuf_clear(dmu_buf_impl_t *db)
1576fa9e4066Sahrens {
1577744947dcSTom Erickson 	dnode_t *dn;
1578ea8dc4b6Seschrock 	dmu_buf_impl_t *parent = db->db_parent;
1579744947dcSTom Erickson 	dmu_buf_impl_t *dndb;
1580bbfa8ea8SMatthew Ahrens 	boolean_t dbuf_gone = B_FALSE;
1581fa9e4066Sahrens 
1582fa9e4066Sahrens 	ASSERT(MUTEX_HELD(&db->db_mtx));
1583fa9e4066Sahrens 	ASSERT(refcount_is_zero(&db->db_holds));
1584fa9e4066Sahrens 
1585ea8dc4b6Seschrock 	dbuf_evict_user(db);
1586ea8dc4b6Seschrock 
1587fa9e4066Sahrens 	if (db->db_state == DB_CACHED) {
1588ea8dc4b6Seschrock 		ASSERT(db->db.db_data != NULL);
15890a586ceaSMark Shellenbaum 		if (db->db_blkid == DMU_BONUS_BLKID) {
1590ea8dc4b6Seschrock 			zio_buf_free(db->db.db_data, DN_MAX_BONUSLEN);
15915a98e54bSBrendan Gregg - Sun Microsystems 			arc_space_return(DN_MAX_BONUSLEN, ARC_SPACE_OTHER);
15920e8c6158Smaybee 		}
1593fa9e4066Sahrens 		db->db.db_data = NULL;
1594fa9e4066Sahrens 		db->db_state = DB_UNCACHED;
1595fa9e4066Sahrens 	}
1596fa9e4066Sahrens 
159782c9918fSTim Haley 	ASSERT(db->db_state == DB_UNCACHED || db->db_state == DB_NOFILL);
1598fa9e4066Sahrens 	ASSERT(db->db_data_pending == NULL);
1599fa9e4066Sahrens 
1600ea8dc4b6Seschrock 	db->db_state = DB_EVICTING;
1601ea8dc4b6Seschrock 	db->db_blkptr = NULL;
1602ea8dc4b6Seschrock 
1603744947dcSTom Erickson 	DB_DNODE_ENTER(db);
1604744947dcSTom Erickson 	dn = DB_DNODE(db);
1605744947dcSTom Erickson 	dndb = dn->dn_dbuf;
16060a586ceaSMark Shellenbaum 	if (db->db_blkid != DMU_BONUS_BLKID && MUTEX_HELD(&dn->dn_dbufs_mtx)) {
1607*0f6d88adSAlex Reece 		avl_remove(&dn->dn_dbufs, db);
1608744947dcSTom Erickson 		(void) atomic_dec_32_nv(&dn->dn_dbufs_count);
1609744947dcSTom Erickson 		membar_producer();
1610744947dcSTom Erickson 		DB_DNODE_EXIT(db);
1611744947dcSTom Erickson 		/*
1612744947dcSTom Erickson 		 * Decrementing the dbuf count means that the hold corresponding
1613744947dcSTom Erickson 		 * to the removed dbuf is no longer discounted in dnode_move(),
1614744947dcSTom Erickson 		 * so the dnode cannot be moved until after we release the hold.
1615744947dcSTom Erickson 		 * The membar_producer() ensures visibility of the decremented
1616744947dcSTom Erickson 		 * value in dnode_move(), since DB_DNODE_EXIT doesn't actually
1617744947dcSTom Erickson 		 * release any lock.
1618744947dcSTom Erickson 		 */
1619ea8dc4b6Seschrock 		dnode_rele(dn, db);
1620744947dcSTom Erickson 		db->db_dnode_handle = NULL;
1621744947dcSTom Erickson 	} else {
1622744947dcSTom Erickson 		DB_DNODE_EXIT(db);
1623ea8dc4b6Seschrock 	}
1624ea8dc4b6Seschrock 
1625ea8dc4b6Seschrock 	if (db->db_buf)
1626bbfa8ea8SMatthew Ahrens 		dbuf_gone = arc_clear_callback(db->db_buf);
1627ea8dc4b6Seschrock 
1628ea8dc4b6Seschrock 	if (!dbuf_gone)
1629ea8dc4b6Seschrock 		mutex_exit(&db->db_mtx);
1630fa9e4066Sahrens 
1631fa9e4066Sahrens 	/*
1632744947dcSTom Erickson 	 * If this dbuf is referenced from an indirect dbuf,
1633fa9e4066Sahrens 	 * decrement the ref count on the indirect dbuf.
1634fa9e4066Sahrens 	 */
1635c543ec06Sahrens 	if (parent && parent != dndb)
1636ea8dc4b6Seschrock 		dbuf_rele(parent, db);
1637fa9e4066Sahrens }
1638fa9e4066Sahrens 
1639fa9e4066Sahrens static int
1640fa9e4066Sahrens dbuf_findbp(dnode_t *dn, int level, uint64_t blkid, int fail_sparse,
1641fa9e4066Sahrens     dmu_buf_impl_t **parentp, blkptr_t **bpp)
1642fa9e4066Sahrens {
1643fa9e4066Sahrens 	int nlevels, epbs;
1644fa9e4066Sahrens 
16450b69c2f0Sahrens 	*parentp = NULL;
16460b69c2f0Sahrens 	*bpp = NULL;
16470b69c2f0Sahrens 
16480a586ceaSMark Shellenbaum 	ASSERT(blkid != DMU_BONUS_BLKID);
16490a586ceaSMark Shellenbaum 
16500a586ceaSMark Shellenbaum 	if (blkid == DMU_SPILL_BLKID) {
16510a586ceaSMark Shellenbaum 		mutex_enter(&dn->dn_mtx);
165206e0070dSMark Shellenbaum 		if (dn->dn_have_spill &&
165306e0070dSMark Shellenbaum 		    (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR))
16540a586ceaSMark Shellenbaum 			*bpp = &dn->dn_phys->dn_spill;
16550a586ceaSMark Shellenbaum 		else
16560a586ceaSMark Shellenbaum 			*bpp = NULL;
16570a586ceaSMark Shellenbaum 		dbuf_add_ref(dn->dn_dbuf, NULL);
16580a586ceaSMark Shellenbaum 		*parentp = dn->dn_dbuf;
16590a586ceaSMark Shellenbaum 		mutex_exit(&dn->dn_mtx);
16600a586ceaSMark Shellenbaum 		return (0);
16610a586ceaSMark Shellenbaum 	}
1662ea8dc4b6Seschrock 
1663fa9e4066Sahrens 	if (dn->dn_phys->dn_nlevels == 0)
1664fa9e4066Sahrens 		nlevels = 1;
1665fa9e4066Sahrens 	else
1666fa9e4066Sahrens 		nlevels = dn->dn_phys->dn_nlevels;
1667fa9e4066Sahrens 
1668fa9e4066Sahrens 	epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
1669fa9e4066Sahrens 
1670fa9e4066Sahrens 	ASSERT3U(level * epbs, <, 64);
1671fa9e4066Sahrens 	ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock));
1672ea8dc4b6Seschrock 	if (level >= nlevels ||
1673fa9e4066Sahrens 	    (blkid > (dn->dn_phys->dn_maxblkid >> (level * epbs)))) {
1674fa9e4066Sahrens 		/* the buffer has no parent yet */
1675be6fd75aSMatthew Ahrens 		return (SET_ERROR(ENOENT));
1676fa9e4066Sahrens 	} else if (level < nlevels-1) {
1677fa9e4066Sahrens 		/* this block is referenced from an indirect block */
1678fa9e4066Sahrens 		int err = dbuf_hold_impl(dn, level+1,
1679fa9e4066Sahrens 		    blkid >> epbs, fail_sparse, NULL, parentp);
1680fa9e4066Sahrens 		if (err)
1681fa9e4066Sahrens 			return (err);
1682ea8dc4b6Seschrock 		err = dbuf_read(*parentp, NULL,
1683ea8dc4b6Seschrock 		    (DB_RF_HAVESTRUCT | DB_RF_NOPREFETCH | DB_RF_CANFAIL));
1684c543ec06Sahrens 		if (err) {
1685c543ec06Sahrens 			dbuf_rele(*parentp, NULL);
1686c543ec06Sahrens 			*parentp = NULL;
1687c543ec06Sahrens 			return (err);
1688ea8dc4b6Seschrock 		}
1689c543ec06Sahrens 		*bpp = ((blkptr_t *)(*parentp)->db.db_data) +
1690c543ec06Sahrens 		    (blkid & ((1ULL << epbs) - 1));
1691c543ec06Sahrens 		return (0);
1692fa9e4066Sahrens 	} else {
1693fa9e4066Sahrens 		/* the block is referenced from the dnode */
1694fa9e4066Sahrens 		ASSERT3U(level, ==, nlevels-1);
1695fa9e4066Sahrens 		ASSERT(dn->dn_phys->dn_nblkptr == 0 ||
1696fa9e4066Sahrens 		    blkid < dn->dn_phys->dn_nblkptr);
1697c543ec06Sahrens 		if (dn->dn_dbuf) {
1698c543ec06Sahrens 			dbuf_add_ref(dn->dn_dbuf, NULL);
1699c543ec06Sahrens 			*parentp = dn->dn_dbuf;
1700c543ec06Sahrens 		}
1701fa9e4066Sahrens 		*bpp = &dn->dn_phys->dn_blkptr[blkid];
1702fa9e4066Sahrens 		return (0);
1703fa9e4066Sahrens 	}
1704fa9e4066Sahrens }
1705fa9e4066Sahrens 
1706fa9e4066Sahrens static dmu_buf_impl_t *
1707fa9e4066Sahrens dbuf_create(dnode_t *dn, uint8_t level, uint64_t blkid,
1708fa9e4066Sahrens     dmu_buf_impl_t *parent, blkptr_t *blkptr)
1709fa9e4066Sahrens {
1710503ad85cSMatthew Ahrens 	objset_t *os = dn->dn_objset;
1711fa9e4066Sahrens 	dmu_buf_impl_t *db, *odb;
1712fa9e4066Sahrens 
1713fa9e4066Sahrens 	ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock));
1714fa9e4066Sahrens 	ASSERT(dn->dn_type != DMU_OT_NONE);
1715fa9e4066Sahrens 
1716fa9e4066Sahrens 	db = kmem_cache_alloc(dbuf_cache, KM_SLEEP);
1717fa9e4066Sahrens 
1718fa9e4066Sahrens 	db->db_objset = os;
1719fa9e4066Sahrens 	db->db.db_object = dn->dn_object;
1720fa9e4066Sahrens 	db->db_level = level;
1721fa9e4066Sahrens 	db->db_blkid = blkid;
1722c717a561Smaybee 	db->db_last_dirty = NULL;
1723ea8dc4b6Seschrock 	db->db_dirtycnt = 0;
1724744947dcSTom Erickson 	db->db_dnode_handle = dn->dn_handle;
1725ea8dc4b6Seschrock 	db->db_parent = parent;
1726ea8dc4b6Seschrock 	db->db_blkptr = blkptr;
1727fa9e4066Sahrens 
1728c717a561Smaybee 	db->db_user_ptr = NULL;
1729c717a561Smaybee 	db->db_user_data_ptr_ptr = NULL;
1730c717a561Smaybee 	db->db_evict_func = NULL;
1731c717a561Smaybee 	db->db_immediate_evict = 0;
1732c717a561Smaybee 	db->db_freed_in_flight = 0;
1733ea8dc4b6Seschrock 
17340a586ceaSMark Shellenbaum 	if (blkid == DMU_BONUS_BLKID) {
1735ea8dc4b6Seschrock 		ASSERT3P(parent, ==, dn->dn_dbuf);
17361934e92fSmaybee 		db->db.db_size = DN_MAX_BONUSLEN -
17371934e92fSmaybee 		    (dn->dn_nblkptr-1) * sizeof (blkptr_t);
17381934e92fSmaybee 		ASSERT3U(db->db.db_size, >=, dn->dn_bonuslen);
17390a586ceaSMark Shellenbaum 		db->db.db_offset = DMU_BONUS_BLKID;
1740ea8dc4b6Seschrock 		db->db_state = DB_UNCACHED;
1741ea8dc4b6Seschrock 		/* the bonus dbuf is not placed in the hash table */
17425a98e54bSBrendan Gregg - Sun Microsystems 		arc_space_consume(sizeof (dmu_buf_impl_t), ARC_SPACE_OTHER);
1743ea8dc4b6Seschrock 		return (db);
17440a586ceaSMark Shellenbaum 	} else if (blkid == DMU_SPILL_BLKID) {
17450a586ceaSMark Shellenbaum 		db->db.db_size = (blkptr != NULL) ?
17460a586ceaSMark Shellenbaum 		    BP_GET_LSIZE(blkptr) : SPA_MINBLOCKSIZE;
17470a586ceaSMark Shellenbaum 		db->db.db_offset = 0;
1748fa9e4066Sahrens 	} else {
1749fa9e4066Sahrens 		int blocksize =
175069962b56SMatthew Ahrens 		    db->db_level ? 1 << dn->dn_indblkshift : dn->dn_datablksz;
1751fa9e4066Sahrens 		db->db.db_size = blocksize;
1752fa9e4066Sahrens 		db->db.db_offset = db->db_blkid * blocksize;
1753fa9e4066Sahrens 	}
1754fa9e4066Sahrens 
1755fa9e4066Sahrens 	/*
1756fa9e4066Sahrens 	 * Hold the dn_dbufs_mtx while we get the new dbuf
1757fa9e4066Sahrens 	 * in the hash table *and* added to the dbufs list.
1758fa9e4066Sahrens 	 * This prevents a possible deadlock with someone
1759fa9e4066Sahrens 	 * trying to look up this dbuf before its added to the
1760fa9e4066Sahrens 	 * dn_dbufs list.
1761fa9e4066Sahrens 	 */
1762fa9e4066Sahrens 	mutex_enter(&dn->dn_dbufs_mtx);
1763ea8dc4b6Seschrock 	db->db_state = DB_EVICTING;
1764fa9e4066Sahrens 	if ((odb = dbuf_hash_insert(db)) != NULL) {
1765fa9e4066Sahrens 		/* someone else inserted it first */
1766fa9e4066Sahrens 		kmem_cache_free(dbuf_cache, db);
1767fa9e4066Sahrens 		mutex_exit(&dn->dn_dbufs_mtx);
1768fa9e4066Sahrens 		return (odb);
1769fa9e4066Sahrens 	}
1770*0f6d88adSAlex Reece 	avl_add(&dn->dn_dbufs, db);
1771713d6c20SMatthew Ahrens 	if (db->db_level == 0 && db->db_blkid >=
1772713d6c20SMatthew Ahrens 	    dn->dn_unlisted_l0_blkid)
1773713d6c20SMatthew Ahrens 		dn->dn_unlisted_l0_blkid = db->db_blkid + 1;
1774ea8dc4b6Seschrock 	db->db_state = DB_UNCACHED;
1775fa9e4066Sahrens 	mutex_exit(&dn->dn_dbufs_mtx);
17765a98e54bSBrendan Gregg - Sun Microsystems 	arc_space_consume(sizeof (dmu_buf_impl_t), ARC_SPACE_OTHER);
1777fa9e4066Sahrens 
1778fa9e4066Sahrens 	if (parent && parent != dn->dn_dbuf)
1779fa9e4066Sahrens 		dbuf_add_ref(parent, db);
1780fa9e4066Sahrens 
1781ea8dc4b6Seschrock 	ASSERT(dn->dn_object == DMU_META_DNODE_OBJECT ||
1782ea8dc4b6Seschrock 	    refcount_count(&dn->dn_holds) > 0);
1783fa9e4066Sahrens 	(void) refcount_add(&dn->dn_holds, db);
1784744947dcSTom Erickson 	(void) atomic_inc_32_nv(&dn->dn_dbufs_count);
1785fa9e4066Sahrens 
1786fa9e4066Sahrens 	dprintf_dbuf(db, "db=%p\n", db);
1787fa9e4066Sahrens 
1788fa9e4066Sahrens 	return (db);
1789fa9e4066Sahrens }
1790fa9e4066Sahrens 
1791fa9e4066Sahrens static int
1792ea8dc4b6Seschrock dbuf_do_evict(void *private)
1793fa9e4066Sahrens {
1794bbfa8ea8SMatthew Ahrens 	dmu_buf_impl_t *db = private;
1795fa9e4066Sahrens 
1796ea8dc4b6Seschrock 	if (!MUTEX_HELD(&db->db_mtx))
1797ea8dc4b6Seschrock 		mutex_enter(&db->db_mtx);
1798fa9e4066Sahrens 
1799ea8dc4b6Seschrock 	ASSERT(refcount_is_zero(&db->db_holds));
1800fa9e4066Sahrens 
1801ea8dc4b6Seschrock 	if (db->db_state != DB_EVICTING) {
1802ea8dc4b6Seschrock 		ASSERT(db->db_state == DB_CACHED);
1803ea8dc4b6Seschrock 		DBUF_VERIFY(db);
1804ea8dc4b6Seschrock 		db->db_buf = NULL;
1805ea8dc4b6Seschrock 		dbuf_evict(db);
1806ea8dc4b6Seschrock 	} else {
1807ea8dc4b6Seschrock 		mutex_exit(&db->db_mtx);
1808ea8dc4b6Seschrock 		dbuf_destroy(db);
1809fa9e4066Sahrens 	}
1810ea8dc4b6Seschrock 	return (0);
1811fa9e4066Sahrens }
1812fa9e4066Sahrens 
1813fa9e4066Sahrens static void
1814fa9e4066Sahrens dbuf_destroy(dmu_buf_impl_t *db)
1815fa9e4066Sahrens {
1816fa9e4066Sahrens 	ASSERT(refcount_is_zero(&db->db_holds));
1817fa9e4066Sahrens 
18180a586ceaSMark Shellenbaum 	if (db->db_blkid != DMU_BONUS_BLKID) {
1819ea8dc4b6Seschrock 		/*
1820ea8dc4b6Seschrock 		 * If this dbuf is still on the dn_dbufs list,
1821ea8dc4b6Seschrock 		 * remove it from that list.
1822ea8dc4b6Seschrock 		 */
1823744947dcSTom Erickson 		if (db->db_dnode_handle != NULL) {
1824744947dcSTom Erickson 			dnode_t *dn;
18251934e92fSmaybee 
1826744947dcSTom Erickson 			DB_DNODE_ENTER(db);
1827744947dcSTom Erickson 			dn = DB_DNODE(db);
18281934e92fSmaybee 			mutex_enter(&dn->dn_dbufs_mtx);
1829*0f6d88adSAlex Reece 			avl_remove(&dn->dn_dbufs, db);
1830744947dcSTom Erickson 			(void) atomic_dec_32_nv(&dn->dn_dbufs_count);
1831c543ec06Sahrens 			mutex_exit(&dn->dn_dbufs_mtx);
1832744947dcSTom Erickson 			DB_DNODE_EXIT(db);
1833744947dcSTom Erickson 			/*
1834744947dcSTom Erickson 			 * Decrementing the dbuf count means that the hold
1835744947dcSTom Erickson 			 * corresponding to the removed dbuf is no longer
1836744947dcSTom Erickson 			 * discounted in dnode_move(), so the dnode cannot be
1837744947dcSTom Erickson 			 * moved until after we release the hold.
1838744947dcSTom Erickson 			 */
1839ea8dc4b6Seschrock 			dnode_rele(dn, db);
1840744947dcSTom Erickson 			db->db_dnode_handle = NULL;
1841ea8dc4b6Seschrock 		}
1842ea8dc4b6Seschrock 		dbuf_hash_remove(db);
1843ea8dc4b6Seschrock 	}
1844ea8dc4b6Seschrock 	db->db_parent = NULL;
1845ea8dc4b6Seschrock 	db->db_buf = NULL;
1846ea8dc4b6Seschrock 
1847fa9e4066Sahrens 	ASSERT(db->db.db_data == NULL);
1848fa9e4066Sahrens 	ASSERT(db->db_hash_next == NULL);
1849fa9e4066Sahrens 	ASSERT(db->db_blkptr == NULL);
1850fa9e4066Sahrens 	ASSERT(db->db_data_pending == NULL);
1851fa9e4066Sahrens 
1852fa9e4066Sahrens 	kmem_cache_free(dbuf_cache, db);
18535a98e54bSBrendan Gregg - Sun Microsystems 	arc_space_return(sizeof (dmu_buf_impl_t), ARC_SPACE_OTHER);
1854fa9e4066Sahrens }
1855fa9e4066Sahrens 
1856fa9e4066Sahrens void
185769962b56SMatthew Ahrens dbuf_prefetch(dnode_t *dn, uint64_t blkid, zio_priority_t prio)
1858fa9e4066Sahrens {
185913506d1eSmaybee 	dmu_buf_impl_t *db = NULL;
1860fa9e4066Sahrens 	blkptr_t *bp = NULL;
1861fa9e4066Sahrens 
18620a586ceaSMark Shellenbaum 	ASSERT(blkid != DMU_BONUS_BLKID);
1863fa9e4066Sahrens 	ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock));
1864fa9e4066Sahrens 
1865fa9e4066Sahrens 	if (dnode_block_freed(dn, blkid))
1866fa9e4066Sahrens 		return;
1867fa9e4066Sahrens 
1868fa9e4066Sahrens 	/* dbuf_find() returns with db_mtx held */
1869fa9e4066Sahrens 	if (db = dbuf_find(dn, 0, blkid)) {
18709e9c486fSGeorge Wilson 		/*
18719e9c486fSGeorge Wilson 		 * This dbuf is already in the cache.  We assume that
18729e9c486fSGeorge Wilson 		 * it is already CACHED, or else about to be either
18739e9c486fSGeorge Wilson 		 * read or filled.
18749e9c486fSGeorge Wilson 		 */
1875fa9e4066Sahrens 		mutex_exit(&db->db_mtx);
18769e9c486fSGeorge Wilson 		return;
1877fa9e4066Sahrens 	}
1878fa9e4066Sahrens 
187913506d1eSmaybee 	if (dbuf_findbp(dn, 0, blkid, TRUE, &db, &bp) == 0) {
18805d7b4d43SMatthew Ahrens 		if (bp && !BP_IS_HOLE(bp) && !BP_IS_EMBEDDED(bp)) {
1881b24ab676SJeff Bonwick 			dsl_dataset_t *ds = dn->dn_objset->os_dsl_dataset;
188213506d1eSmaybee 			uint32_t aflags = ARC_NOWAIT | ARC_PREFETCH;
18837802d7bfSMatthew Ahrens 			zbookmark_phys_t zb;
1884b24ab676SJeff Bonwick 
1885b24ab676SJeff Bonwick 			SET_BOOKMARK(&zb, ds ? ds->ds_object : DMU_META_OBJSET,
1886b24ab676SJeff Bonwick 			    dn->dn_object, 0, blkid);
1887ea8dc4b6Seschrock 
18881b912ec7SGeorge Wilson 			(void) arc_read(NULL, dn->dn_objset->os_spa,
188969962b56SMatthew Ahrens 			    bp, NULL, NULL, prio,
1890fa9e4066Sahrens 			    ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE,
189113506d1eSmaybee 			    &aflags, &zb);
1892fa9e4066Sahrens 		}
189313506d1eSmaybee 		if (db)
189413506d1eSmaybee 			dbuf_rele(db, NULL);
1895fa9e4066Sahrens 	}
1896fa9e4066Sahrens }
1897fa9e4066Sahrens 
1898fa9e4066Sahrens /*
1899fa9e4066Sahrens  * Returns with db_holds incremented, and db_mtx not held.
1900fa9e4066Sahrens  * Note: dn_struct_rwlock must be held.
1901fa9e4066Sahrens  */
1902fa9e4066Sahrens int
1903fa9e4066Sahrens dbuf_hold_impl(dnode_t *dn, uint8_t level, uint64_t blkid, int fail_sparse,
1904fa9e4066Sahrens     void *tag, dmu_buf_impl_t **dbp)
1905fa9e4066Sahrens {
1906fa9e4066Sahrens 	dmu_buf_impl_t *db, *parent = NULL;
1907fa9e4066Sahrens 
19080a586ceaSMark Shellenbaum 	ASSERT(blkid != DMU_BONUS_BLKID);
1909fa9e4066Sahrens 	ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock));
1910fa9e4066Sahrens 	ASSERT3U(dn->dn_nlevels, >, level);
1911fa9e4066Sahrens 
1912fa9e4066Sahrens 	*dbp = NULL;
1913ea8dc4b6Seschrock top:
1914fa9e4066Sahrens 	/* dbuf_find() returns with db_mtx held */
1915fa9e4066Sahrens 	db = dbuf_find(dn, level, blkid);
1916fa9e4066Sahrens 
1917fa9e4066Sahrens 	if (db == NULL) {
1918fa9e4066Sahrens 		blkptr_t *bp = NULL;
1919fa9e4066Sahrens 		int err;
1920fa9e4066Sahrens 
1921c543ec06Sahrens 		ASSERT3P(parent, ==, NULL);
1922fa9e4066Sahrens 		err = dbuf_findbp(dn, level, blkid, fail_sparse, &parent, &bp);
1923fa9e4066Sahrens 		if (fail_sparse) {
1924fa9e4066Sahrens 			if (err == 0 && bp && BP_IS_HOLE(bp))
1925be6fd75aSMatthew Ahrens 				err = SET_ERROR(ENOENT);
1926fa9e4066Sahrens 			if (err) {
1927c543ec06Sahrens 				if (parent)
1928ea8dc4b6Seschrock 					dbuf_rele(parent, NULL);
1929fa9e4066Sahrens 				return (err);
1930fa9e4066Sahrens 			}
1931fa9e4066Sahrens 		}
1932ea8dc4b6Seschrock 		if (err && err != ENOENT)
1933ea8dc4b6Seschrock 			return (err);
1934fa9e4066Sahrens 		db = dbuf_create(dn, level, blkid, parent, bp);
1935fa9e4066Sahrens 	}
1936fa9e4066Sahrens 
1937ea8dc4b6Seschrock 	if (db->db_buf && refcount_is_zero(&db->db_holds)) {
1938ea8dc4b6Seschrock 		arc_buf_add_ref(db->db_buf, db);
1939ea8dc4b6Seschrock 		if (db->db_buf->b_data == NULL) {
1940ea8dc4b6Seschrock 			dbuf_clear(db);
1941c543ec06Sahrens 			if (parent) {
1942c543ec06Sahrens 				dbuf_rele(parent, NULL);
1943c543ec06Sahrens 				parent = NULL;
1944c543ec06Sahrens 			}
1945ea8dc4b6Seschrock 			goto top;
1946ea8dc4b6Seschrock 		}
1947ea8dc4b6Seschrock 		ASSERT3P(db->db.db_data, ==, db->db_buf->b_data);
1948ea8dc4b6Seschrock 	}
1949ea8dc4b6Seschrock 
1950ea8dc4b6Seschrock 	ASSERT(db->db_buf == NULL || arc_referenced(db->db_buf));
1951ea8dc4b6Seschrock 
1952fa9e4066Sahrens 	/*
1953c717a561Smaybee 	 * If this buffer is currently syncing out, and we are are
1954c717a561Smaybee 	 * still referencing it from db_data, we need to make a copy
1955c717a561Smaybee 	 * of it in case we decide we want to dirty it again in this txg.
1956fa9e4066Sahrens 	 */
19570a586ceaSMark Shellenbaum 	if (db->db_level == 0 && db->db_blkid != DMU_BONUS_BLKID &&
1958ea8dc4b6Seschrock 	    dn->dn_object != DMU_META_DNODE_OBJECT &&
1959c717a561Smaybee 	    db->db_state == DB_CACHED && db->db_data_pending) {
1960c717a561Smaybee 		dbuf_dirty_record_t *dr = db->db_data_pending;
1961fa9e4066Sahrens 
1962c717a561Smaybee 		if (dr->dt.dl.dr_data == db->db_buf) {
1963c717a561Smaybee 			arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db);
1964c717a561Smaybee 
1965c717a561Smaybee 			dbuf_set_data(db,
1966744947dcSTom Erickson 			    arc_buf_alloc(dn->dn_objset->os_spa,
1967c717a561Smaybee 			    db->db.db_size, db, type));
1968c717a561Smaybee 			bcopy(dr->dt.dl.dr_data->b_data, db->db.db_data,
1969c717a561Smaybee 			    db->db.db_size);
1970c717a561Smaybee 		}
1971fa9e4066Sahrens 	}
1972fa9e4066Sahrens 
1973ea8dc4b6Seschrock 	(void) refcount_add(&db->db_holds, tag);
1974fa9e4066Sahrens 	dbuf_update_data(db);
19759c9dc39aSek 	DBUF_VERIFY(db);
1976fa9e4066Sahrens 	mutex_exit(&db->db_mtx);
1977fa9e4066Sahrens 
1978fa9e4066Sahrens 	/* NOTE: we can't rele the parent until after we drop the db_mtx */
1979c543ec06Sahrens 	if (parent)
1980ea8dc4b6Seschrock 		dbuf_rele(parent, NULL);
1981fa9e4066Sahrens 
1982744947dcSTom Erickson 	ASSERT3P(DB_DNODE(db), ==, dn);
1983fa9e4066Sahrens 	ASSERT3U(db->db_blkid, ==, blkid);
1984fa9e4066Sahrens 	ASSERT3U(db->db_level, ==, level);
1985fa9e4066Sahrens 	*dbp = db;
1986fa9e4066Sahrens 
1987fa9e4066Sahrens 	return (0);
1988fa9e4066Sahrens }
1989fa9e4066Sahrens 
1990fa9e4066Sahrens dmu_buf_impl_t *
1991ea8dc4b6Seschrock dbuf_hold(dnode_t *dn, uint64_t blkid, void *tag)
1992fa9e4066Sahrens {
1993fa9e4066Sahrens 	dmu_buf_impl_t *db;
1994ea8dc4b6Seschrock 	int err = dbuf_hold_impl(dn, 0, blkid, FALSE, tag, &db);
1995ea8dc4b6Seschrock 	return (err ? NULL : db);
1996fa9e4066Sahrens }
1997fa9e4066Sahrens 
1998fa9e4066Sahrens dmu_buf_impl_t *
1999fa9e4066Sahrens dbuf_hold_level(dnode_t *dn, int level, uint64_t blkid, void *tag)
2000fa9e4066Sahrens {
2001fa9e4066Sahrens 	dmu_buf_impl_t *db;
2002ea8dc4b6Seschrock 	int err = dbuf_hold_impl(dn, level, blkid, FALSE, tag, &db);
2003ea8dc4b6Seschrock 	return (err ? NULL : db);
2004fa9e4066Sahrens }
2005fa9e4066Sahrens 
20061934e92fSmaybee void
2007ea8dc4b6Seschrock dbuf_create_bonus(dnode_t *dn)
2008fa9e4066Sahrens {
2009ea8dc4b6Seschrock 	ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
2010ea8dc4b6Seschrock 
2011ea8dc4b6Seschrock 	ASSERT(dn->dn_bonus == NULL);
20120a586ceaSMark Shellenbaum 	dn->dn_bonus = dbuf_create(dn, 0, DMU_BONUS_BLKID, dn->dn_dbuf, NULL);
20130a586ceaSMark Shellenbaum }
20140a586ceaSMark Shellenbaum 
20150a586ceaSMark Shellenbaum int
20160a586ceaSMark Shellenbaum dbuf_spill_set_blksz(dmu_buf_t *db_fake, uint64_t blksz, dmu_tx_t *tx)
20170a586ceaSMark Shellenbaum {
20180a586ceaSMark Shellenbaum 	dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
2019744947dcSTom Erickson 	dnode_t *dn;
2020744947dcSTom Erickson 
20210a586ceaSMark Shellenbaum 	if (db->db_blkid != DMU_SPILL_BLKID)
2022be6fd75aSMatthew Ahrens 		return (SET_ERROR(ENOTSUP));
20230a586ceaSMark Shellenbaum 	if (blksz == 0)
20240a586ceaSMark Shellenbaum 		blksz = SPA_MINBLOCKSIZE;
20250a586ceaSMark Shellenbaum 	if (blksz > SPA_MAXBLOCKSIZE)
20260a586ceaSMark Shellenbaum 		blksz = SPA_MAXBLOCKSIZE;
20270a586ceaSMark Shellenbaum 	else
20280a586ceaSMark Shellenbaum 		blksz = P2ROUNDUP(blksz, SPA_MINBLOCKSIZE);
20290a586ceaSMark Shellenbaum 
2030744947dcSTom Erickson 	DB_DNODE_ENTER(db);
2031744947dcSTom Erickson 	dn = DB_DNODE(db);
2032744947dcSTom Erickson 	rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
20330a586ceaSMark Shellenbaum 	dbuf_new_size(db, blksz, tx);
2034744947dcSTom Erickson 	rw_exit(&dn->dn_struct_rwlock);
2035744947dcSTom Erickson 	DB_DNODE_EXIT(db);
20360a586ceaSMark Shellenbaum 
20370a586ceaSMark Shellenbaum 	return (0);
20380a586ceaSMark Shellenbaum }
20390a586ceaSMark Shellenbaum 
20400a586ceaSMark Shellenbaum void
20410a586ceaSMark Shellenbaum dbuf_rm_spill(dnode_t *dn, dmu_tx_t *tx)
20420a586ceaSMark Shellenbaum {
20430a586ceaSMark Shellenbaum 	dbuf_free_range(dn, DMU_SPILL_BLKID, DMU_SPILL_BLKID, tx);
2044fa9e4066Sahrens }
2045fa9e4066Sahrens 
2046ea8dc4b6Seschrock #pragma weak dmu_buf_add_ref = dbuf_add_ref
2047fa9e4066Sahrens void
2048fa9e4066Sahrens dbuf_add_ref(dmu_buf_impl_t *db, void *tag)
2049fa9e4066Sahrens {
2050ea8dc4b6Seschrock 	int64_t holds = refcount_add(&db->db_holds, tag);
2051ea8dc4b6Seschrock 	ASSERT(holds > 1);
2052fa9e4066Sahrens }
2053fa9e4066Sahrens 
2054744947dcSTom Erickson /*
2055744947dcSTom Erickson  * If you call dbuf_rele() you had better not be referencing the dnode handle
2056744947dcSTom Erickson  * unless you have some other direct or indirect hold on the dnode. (An indirect
2057744947dcSTom Erickson  * hold is a hold on one of the dnode's dbufs, including the bonus buffer.)
2058744947dcSTom Erickson  * Without that, the dbuf_rele() could lead to a dnode_rele() followed by the
2059744947dcSTom Erickson  * dnode's parent dbuf evicting its dnode handles.
2060744947dcSTom Erickson  */
2061fa9e4066Sahrens void
2062ea8dc4b6Seschrock dbuf_rele(dmu_buf_impl_t *db, void *tag)
2063b24ab676SJeff Bonwick {
2064b24ab676SJeff Bonwick 	mutex_enter(&db->db_mtx);
2065b24ab676SJeff Bonwick 	dbuf_rele_and_unlock(db, tag);
2066b24ab676SJeff Bonwick }
2067b24ab676SJeff Bonwick 
206843466aaeSMax Grossman void
206943466aaeSMax Grossman dmu_buf_rele(dmu_buf_t *db, void *tag)
207043466aaeSMax Grossman {
207143466aaeSMax Grossman 	dbuf_rele((dmu_buf_impl_t *)db, tag);
207243466aaeSMax Grossman }
207343466aaeSMax Grossman 
2074b24ab676SJeff Bonwick /*
2075b24ab676SJeff Bonwick  * dbuf_rele() for an already-locked dbuf.  This is necessary to allow
2076b24ab676SJeff Bonwick  * db_dirtycnt and db_holds to be updated atomically.
2077b24ab676SJeff Bonwick  */
2078b24ab676SJeff Bonwick void
2079b24ab676SJeff Bonwick dbuf_rele_and_unlock(dmu_buf_impl_t *db, void *tag)
2080fa9e4066Sahrens {
2081fa9e4066Sahrens 	int64_t holds;
2082fa9e4066Sahrens 
2083b24ab676SJeff Bonwick 	ASSERT(MUTEX_HELD(&db->db_mtx));
20849c9dc39aSek 	DBUF_VERIFY(db);
2085fa9e4066Sahrens 
2086744947dcSTom Erickson 	/*
2087744947dcSTom Erickson 	 * Remove the reference to the dbuf before removing its hold on the
2088744947dcSTom Erickson 	 * dnode so we can guarantee in dnode_move() that a referenced bonus
2089744947dcSTom Erickson 	 * buffer has a corresponding dnode hold.
2090744947dcSTom Erickson 	 */
2091fa9e4066Sahrens 	holds = refcount_remove(&db->db_holds, tag);
2092ea8dc4b6Seschrock 	ASSERT(holds >= 0);
2093ea8dc4b6Seschrock 
2094c717a561Smaybee 	/*
2095c717a561Smaybee 	 * We can't freeze indirects if there is a possibility that they
2096c717a561Smaybee 	 * may be modified in the current syncing context.
2097c717a561Smaybee 	 */
2098c717a561Smaybee 	if (db->db_buf && holds == (db->db_level == 0 ? db->db_dirtycnt : 0))
20996b4acc8bSahrens 		arc_buf_freeze(db->db_buf);
21006b4acc8bSahrens 
2101ea8dc4b6Seschrock 	if (holds == db->db_dirtycnt &&
2102c717a561Smaybee 	    db->db_level == 0 && db->db_immediate_evict)
2103ea8dc4b6Seschrock 		dbuf_evict_user(db);
2104fa9e4066Sahrens 
2105fa9e4066Sahrens 	if (holds == 0) {
21060a586ceaSMark Shellenbaum 		if (db->db_blkid == DMU_BONUS_BLKID) {
2107ea8dc4b6Seschrock 			mutex_exit(&db->db_mtx);
2108744947dcSTom Erickson 
2109744947dcSTom Erickson 			/*
2110744947dcSTom Erickson 			 * If the dnode moves here, we cannot cross this barrier
2111744947dcSTom Erickson 			 * until the move completes.
2112744947dcSTom Erickson 			 */
2113744947dcSTom Erickson 			DB_DNODE_ENTER(db);
2114744947dcSTom Erickson 			(void) atomic_dec_32_nv(&DB_DNODE(db)->dn_dbufs_count);
2115744947dcSTom Erickson 			DB_DNODE_EXIT(db);
2116744947dcSTom Erickson 			/*
2117744947dcSTom Erickson 			 * The bonus buffer's dnode hold is no longer discounted
2118744947dcSTom Erickson 			 * in dnode_move(). The dnode cannot move until after
2119744947dcSTom Erickson 			 * the dnode_rele().
2120744947dcSTom Erickson 			 */
2121744947dcSTom Erickson 			dnode_rele(DB_DNODE(db), db);
2122ea8dc4b6Seschrock 		} else if (db->db_buf == NULL) {
2123ea8dc4b6Seschrock 			/*
2124ea8dc4b6Seschrock 			 * This is a special case: we never associated this
2125ea8dc4b6Seschrock 			 * dbuf with any data allocated from the ARC.
2126ea8dc4b6Seschrock 			 */
212782c9918fSTim Haley 			ASSERT(db->db_state == DB_UNCACHED ||
212882c9918fSTim Haley 			    db->db_state == DB_NOFILL);
2129ea8dc4b6Seschrock 			dbuf_evict(db);
21306b4acc8bSahrens 		} else if (arc_released(db->db_buf)) {
2131ea8dc4b6Seschrock 			arc_buf_t *buf = db->db_buf;
2132ea8dc4b6Seschrock 			/*
2133ea8dc4b6Seschrock 			 * This dbuf has anonymous data associated with it.
2134ea8dc4b6Seschrock 			 */
2135ea8dc4b6Seschrock 			dbuf_set_data(db, NULL);
21363b2aab18SMatthew Ahrens 			VERIFY(arc_buf_remove_ref(buf, db));
2137ea8dc4b6Seschrock 			dbuf_evict(db);
2138ea8dc4b6Seschrock 		} else {
21393b2aab18SMatthew Ahrens 			VERIFY(!arc_buf_remove_ref(db->db_buf, db));
21409253d63dSGeorge Wilson 
21419253d63dSGeorge Wilson 			/*
21429253d63dSGeorge Wilson 			 * A dbuf will be eligible for eviction if either the
21439253d63dSGeorge Wilson 			 * 'primarycache' property is set or a duplicate
21449253d63dSGeorge Wilson 			 * copy of this buffer is already cached in the arc.
21459253d63dSGeorge Wilson 			 *
21469253d63dSGeorge Wilson 			 * In the case of the 'primarycache' a buffer
21479253d63dSGeorge Wilson 			 * is considered for eviction if it matches the
21489253d63dSGeorge Wilson 			 * criteria set in the property.
21499253d63dSGeorge Wilson 			 *
21509253d63dSGeorge Wilson 			 * To decide if our buffer is considered a
21519253d63dSGeorge Wilson 			 * duplicate, we must call into the arc to determine
21529253d63dSGeorge Wilson 			 * if multiple buffers are referencing the same
21539253d63dSGeorge Wilson 			 * block on-disk. If so, then we simply evict
21549253d63dSGeorge Wilson 			 * ourselves.
21559253d63dSGeorge Wilson 			 */
2156bbfa8ea8SMatthew Ahrens 			if (!DBUF_IS_CACHEABLE(db)) {
2157bbfa8ea8SMatthew Ahrens 				if (db->db_blkptr != NULL &&
2158bbfa8ea8SMatthew Ahrens 				    !BP_IS_HOLE(db->db_blkptr) &&
2159bbfa8ea8SMatthew Ahrens 				    !BP_IS_EMBEDDED(db->db_blkptr)) {
2160bbfa8ea8SMatthew Ahrens 					spa_t *spa =
2161bbfa8ea8SMatthew Ahrens 					    dmu_objset_spa(db->db_objset);
2162bbfa8ea8SMatthew Ahrens 					blkptr_t bp = *db->db_blkptr;
2163bbfa8ea8SMatthew Ahrens 					dbuf_clear(db);
2164bbfa8ea8SMatthew Ahrens 					arc_freed(spa, &bp);
2165bbfa8ea8SMatthew Ahrens 				} else {
2166bbfa8ea8SMatthew Ahrens 					dbuf_clear(db);
2167bbfa8ea8SMatthew Ahrens 				}
2168bbfa8ea8SMatthew Ahrens 			} else if (arc_buf_eviction_needed(db->db_buf)) {
21693baa08fcSek 				dbuf_clear(db);
2170bbfa8ea8SMatthew Ahrens 			} else {
21713baa08fcSek 				mutex_exit(&db->db_mtx);
2172bbfa8ea8SMatthew Ahrens 			}
2173ea8dc4b6Seschrock 		}
2174fa9e4066Sahrens 	} else {
2175fa9e4066Sahrens 		mutex_exit(&db->db_mtx);
2176fa9e4066Sahrens 	}
2177fa9e4066Sahrens }
2178fa9e4066Sahrens 
2179fa9e4066Sahrens #pragma weak dmu_buf_refcount = dbuf_refcount
2180fa9e4066Sahrens uint64_t
2181fa9e4066Sahrens dbuf_refcount(dmu_buf_impl_t *db)
2182fa9e4066Sahrens {
2183fa9e4066Sahrens 	return (refcount_count(&db->db_holds));
2184fa9e4066Sahrens }
2185fa9e4066Sahrens 
2186fa9e4066Sahrens void *
2187fa9e4066Sahrens dmu_buf_set_user(dmu_buf_t *db_fake, void *user_ptr, void *user_data_ptr_ptr,
2188fa9e4066Sahrens     dmu_buf_evict_func_t *evict_func)
2189fa9e4066Sahrens {
2190fa9e4066Sahrens 	return (dmu_buf_update_user(db_fake, NULL, user_ptr,
2191fa9e4066Sahrens 	    user_data_ptr_ptr, evict_func));
2192fa9e4066Sahrens }
2193fa9e4066Sahrens 
2194fa9e4066Sahrens void *
2195fa9e4066Sahrens dmu_buf_set_user_ie(dmu_buf_t *db_fake, void *user_ptr, void *user_data_ptr_ptr,
2196fa9e4066Sahrens     dmu_buf_evict_func_t *evict_func)
2197fa9e4066Sahrens {
2198fa9e4066Sahrens 	dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
2199fa9e4066Sahrens 
2200c717a561Smaybee 	db->db_immediate_evict = TRUE;
2201fa9e4066Sahrens 	return (dmu_buf_update_user(db_fake, NULL, user_ptr,
2202fa9e4066Sahrens 	    user_data_ptr_ptr, evict_func));
2203fa9e4066Sahrens }
2204fa9e4066Sahrens 
2205fa9e4066Sahrens void *
2206fa9e4066Sahrens dmu_buf_update_user(dmu_buf_t *db_fake, void *old_user_ptr, void *user_ptr,
2207fa9e4066Sahrens     void *user_data_ptr_ptr, dmu_buf_evict_func_t *evict_func)
2208fa9e4066Sahrens {
2209fa9e4066Sahrens 	dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
2210fa9e4066Sahrens 	ASSERT(db->db_level == 0);
2211fa9e4066Sahrens 
2212fa9e4066Sahrens 	ASSERT((user_ptr == NULL) == (evict_func == NULL));
2213fa9e4066Sahrens 
2214fa9e4066Sahrens 	mutex_enter(&db->db_mtx);
2215fa9e4066Sahrens 
2216c717a561Smaybee 	if (db->db_user_ptr == old_user_ptr) {
2217c717a561Smaybee 		db->db_user_ptr = user_ptr;
2218c717a561Smaybee 		db->db_user_data_ptr_ptr = user_data_ptr_ptr;
2219c717a561Smaybee 		db->db_evict_func = evict_func;
2220fa9e4066Sahrens 
2221fa9e4066Sahrens 		dbuf_update_data(db);
2222fa9e4066Sahrens 	} else {
2223c717a561Smaybee 		old_user_ptr = db->db_user_ptr;
2224fa9e4066Sahrens 	}
2225fa9e4066Sahrens 
2226fa9e4066Sahrens 	mutex_exit(&db->db_mtx);
2227fa9e4066Sahrens 	return (old_user_ptr);
2228fa9e4066Sahrens }
2229fa9e4066Sahrens 
2230fa9e4066Sahrens void *
2231fa9e4066Sahrens dmu_buf_get_user(dmu_buf_t *db_fake)
2232fa9e4066Sahrens {
2233fa9e4066Sahrens 	dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
2234fa9e4066Sahrens 	ASSERT(!refcount_is_zero(&db->db_holds));
2235fa9e4066Sahrens 
2236c717a561Smaybee 	return (db->db_user_ptr);
2237fa9e4066Sahrens }
2238fa9e4066Sahrens 
22393d692628SSanjeev Bagewadi boolean_t
22403d692628SSanjeev Bagewadi dmu_buf_freeable(dmu_buf_t *dbuf)
22413d692628SSanjeev Bagewadi {
22423d692628SSanjeev Bagewadi 	boolean_t res = B_FALSE;
22433d692628SSanjeev Bagewadi 	dmu_buf_impl_t *db = (dmu_buf_impl_t *)dbuf;
22443d692628SSanjeev Bagewadi 
22453d692628SSanjeev Bagewadi 	if (db->db_blkptr)
22463d692628SSanjeev Bagewadi 		res = dsl_dataset_block_freeable(db->db_objset->os_dsl_dataset,
2247c7cd2421SGeorge Wilson 		    db->db_blkptr, db->db_blkptr->blk_birth);
22483d692628SSanjeev Bagewadi 
22493d692628SSanjeev Bagewadi 	return (res);
22503d692628SSanjeev Bagewadi }
22513d692628SSanjeev Bagewadi 
225280901aeaSGeorge Wilson blkptr_t *
225380901aeaSGeorge Wilson dmu_buf_get_blkptr(dmu_buf_t *db)
225480901aeaSGeorge Wilson {
225580901aeaSGeorge Wilson 	dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db;
225680901aeaSGeorge Wilson 	return (dbi->db_blkptr);
225780901aeaSGeorge Wilson }
225880901aeaSGeorge Wilson 
2259c717a561Smaybee static void
2260c717a561Smaybee dbuf_check_blkptr(dnode_t *dn, dmu_buf_impl_t *db)
2261fa9e4066Sahrens {
2262c717a561Smaybee 	/* ASSERT(dmu_tx_is_syncing(tx) */
2263c717a561Smaybee 	ASSERT(MUTEX_HELD(&db->db_mtx));
2264c717a561Smaybee 
2265c717a561Smaybee 	if (db->db_blkptr != NULL)
2266c717a561Smaybee 		return;
2267c717a561Smaybee 
22680a586ceaSMark Shellenbaum 	if (db->db_blkid == DMU_SPILL_BLKID) {
22690a586ceaSMark Shellenbaum 		db->db_blkptr = &dn->dn_phys->dn_spill;
22700a586ceaSMark Shellenbaum 		BP_ZERO(db->db_blkptr);
22710a586ceaSMark Shellenbaum 		return;
22720a586ceaSMark Shellenbaum 	}
2273c717a561Smaybee 	if (db->db_level == dn->dn_phys->dn_nlevels-1) {
2274c717a561Smaybee 		/*
2275c717a561Smaybee 		 * This buffer was allocated at a time when there was
2276c717a561Smaybee 		 * no available blkptrs from the dnode, or it was
2277c717a561Smaybee 		 * inappropriate to hook it in (i.e., nlevels mis-match).
2278c717a561Smaybee 		 */
2279c717a561Smaybee 		ASSERT(db->db_blkid < dn->dn_phys->dn_nblkptr);
2280c717a561Smaybee 		ASSERT(db->db_parent == NULL);
2281c717a561Smaybee 		db->db_parent = dn->dn_dbuf;
2282c717a561Smaybee 		db->db_blkptr = &dn->dn_phys->dn_blkptr[db->db_blkid];
2283c717a561Smaybee 		DBUF_VERIFY(db);
2284c717a561Smaybee 	} else {
2285c717a561Smaybee 		dmu_buf_impl_t *parent = db->db_parent;
2286c717a561Smaybee 		int epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
2287c717a561Smaybee 
2288c717a561Smaybee 		ASSERT(dn->dn_phys->dn_nlevels > 1);
2289c717a561Smaybee 		if (parent == NULL) {
2290c717a561Smaybee 			mutex_exit(&db->db_mtx);
2291c717a561Smaybee 			rw_enter(&dn->dn_struct_rwlock, RW_READER);
2292c717a561Smaybee 			(void) dbuf_hold_impl(dn, db->db_level+1,
2293c717a561Smaybee 			    db->db_blkid >> epbs, FALSE, db, &parent);
2294c717a561Smaybee 			rw_exit(&dn->dn_struct_rwlock);
2295c717a561Smaybee 			mutex_enter(&db->db_mtx);
2296c717a561Smaybee 			db->db_parent = parent;
2297c717a561Smaybee 		}
2298c717a561Smaybee 		db->db_blkptr = (blkptr_t *)parent->db.db_data +
2299c717a561Smaybee 		    (db->db_blkid & ((1ULL << epbs) - 1));
2300c717a561Smaybee 		DBUF_VERIFY(db);
2301c717a561Smaybee 	}
2302c717a561Smaybee }
2303c717a561Smaybee 
2304c717a561Smaybee static void
2305c717a561Smaybee dbuf_sync_indirect(dbuf_dirty_record_t *dr, dmu_tx_t *tx)
2306c717a561Smaybee {
2307c717a561Smaybee 	dmu_buf_impl_t *db = dr->dr_dbuf;
2308744947dcSTom Erickson 	dnode_t *dn;
2309c717a561Smaybee 	zio_t *zio;
2310c717a561Smaybee 
2311c717a561Smaybee 	ASSERT(dmu_tx_is_syncing(tx));
2312c717a561Smaybee 
2313c717a561Smaybee 	dprintf_dbuf_bp(db, db->db_blkptr, "blkptr=%p", db->db_blkptr);
2314c717a561Smaybee 
2315c717a561Smaybee 	mutex_enter(&db->db_mtx);
2316c717a561Smaybee 
2317c717a561Smaybee 	ASSERT(db->db_level > 0);
2318c717a561Smaybee 	DBUF_VERIFY(db);
2319c717a561Smaybee 
23203e30c24aSWill Andrews 	/* Read the block if it hasn't been read yet. */
2321c717a561Smaybee 	if (db->db_buf == NULL) {
2322c717a561Smaybee 		mutex_exit(&db->db_mtx);
2323c717a561Smaybee 		(void) dbuf_read(db, NULL, DB_RF_MUST_SUCCEED);
2324c717a561Smaybee 		mutex_enter(&db->db_mtx);
2325c717a561Smaybee 	}
2326c717a561Smaybee 	ASSERT3U(db->db_state, ==, DB_CACHED);
2327c717a561Smaybee 	ASSERT(db->db_buf != NULL);
2328c717a561Smaybee 
2329744947dcSTom Erickson 	DB_DNODE_ENTER(db);
2330744947dcSTom Erickson 	dn = DB_DNODE(db);
23313e30c24aSWill Andrews 	/* Indirect block size must match what the dnode thinks it is. */
2332744947dcSTom Erickson 	ASSERT3U(db->db.db_size, ==, 1<<dn->dn_phys->dn_indblkshift);
2333c717a561Smaybee 	dbuf_check_blkptr(dn, db);
2334744947dcSTom Erickson 	DB_DNODE_EXIT(db);
2335c717a561Smaybee 
23363e30c24aSWill Andrews 	/* Provide the pending dirty record to child dbufs */
2337c717a561Smaybee 	db->db_data_pending = dr;
2338c717a561Smaybee 
2339af2c4821Smaybee 	mutex_exit(&db->db_mtx);
2340088f3894Sahrens 	dbuf_write(dr, db->db_buf, tx);
2341c717a561Smaybee 
2342c717a561Smaybee 	zio = dr->dr_zio;
2343c717a561Smaybee 	mutex_enter(&dr->dt.di.dr_mtx);
2344c717a561Smaybee 	dbuf_sync_list(&dr->dt.di.dr_children, tx);
2345c717a561Smaybee 	ASSERT(list_head(&dr->dt.di.dr_children) == NULL);
2346c717a561Smaybee 	mutex_exit(&dr->dt.di.dr_mtx);
2347c717a561Smaybee 	zio_nowait(zio);
2348c717a561Smaybee }
2349c717a561Smaybee 
2350c717a561Smaybee static void
2351c717a561Smaybee dbuf_sync_leaf(dbuf_dirty_record_t *dr, dmu_tx_t *tx)
2352c717a561Smaybee {
2353c717a561Smaybee 	arc_buf_t **datap = &dr->dt.dl.dr_data;
2354c717a561Smaybee 	dmu_buf_impl_t *db = dr->dr_dbuf;
2355744947dcSTom Erickson 	dnode_t *dn;
2356744947dcSTom Erickson 	objset_t *os;
2357c717a561Smaybee 	uint64_t txg = tx->tx_txg;
2358fa9e4066Sahrens 
2359fa9e4066Sahrens 	ASSERT(dmu_tx_is_syncing(tx));
2360fa9e4066Sahrens 
2361fa9e4066Sahrens 	dprintf_dbuf_bp(db, db->db_blkptr, "blkptr=%p", db->db_blkptr);
2362fa9e4066Sahrens 
2363fa9e4066Sahrens 	mutex_enter(&db->db_mtx);
2364fa9e4066Sahrens 	/*
2365fa9e4066Sahrens 	 * To be synced, we must be dirtied.  But we
2366fa9e4066Sahrens 	 * might have been freed after the dirty.
2367fa9e4066Sahrens 	 */
2368fa9e4066Sahrens 	if (db->db_state == DB_UNCACHED) {
2369fa9e4066Sahrens 		/* This buffer has been freed since it was dirtied */
2370fa9e4066Sahrens 		ASSERT(db->db.db_data == NULL);
2371fa9e4066Sahrens 	} else if (db->db_state == DB_FILL) {
2372fa9e4066Sahrens 		/* This buffer was freed and is now being re-filled */
2373c717a561Smaybee 		ASSERT(db->db.db_data != dr->dt.dl.dr_data);
2374fa9e4066Sahrens 	} else {
237582c9918fSTim Haley 		ASSERT(db->db_state == DB_CACHED || db->db_state == DB_NOFILL);
2376fa9e4066Sahrens 	}
23779c9dc39aSek 	DBUF_VERIFY(db);
2378fa9e4066Sahrens 
2379744947dcSTom Erickson 	DB_DNODE_ENTER(db);
2380744947dcSTom Erickson 	dn = DB_DNODE(db);
2381744947dcSTom Erickson 
23820a586ceaSMark Shellenbaum 	if (db->db_blkid == DMU_SPILL_BLKID) {
23830a586ceaSMark Shellenbaum 		mutex_enter(&dn->dn_mtx);
23840a586ceaSMark Shellenbaum 		dn->dn_phys->dn_flags |= DNODE_FLAG_SPILL_BLKPTR;
23850a586ceaSMark Shellenbaum 		mutex_exit(&dn->dn_mtx);
23860a586ceaSMark Shellenbaum 	}
23870a586ceaSMark Shellenbaum 
2388fa9e4066Sahrens 	/*
2389c717a561Smaybee 	 * If this is a bonus buffer, simply copy the bonus data into the
2390c717a561Smaybee 	 * dnode.  It will be written out when the dnode is synced (and it
2391c717a561Smaybee 	 * will be synced, since it must have been dirty for dbuf_sync to
2392c717a561Smaybee 	 * be called).
2393fa9e4066Sahrens 	 */
23940a586ceaSMark Shellenbaum 	if (db->db_blkid == DMU_BONUS_BLKID) {
2395c717a561Smaybee 		dbuf_dirty_record_t **drp;
23961934e92fSmaybee 
2397ea8dc4b6Seschrock 		ASSERT(*datap != NULL);
2398fb09f5aaSMadhav Suresh 		ASSERT0(db->db_level);
2399ea8dc4b6Seschrock 		ASSERT3U(dn->dn_phys->dn_bonuslen, <=, DN_MAX_BONUSLEN);
2400ea8dc4b6Seschrock 		bcopy(*datap, DN_BONUS(dn->dn_phys), dn->dn_phys->dn_bonuslen);
2401744947dcSTom Erickson 		DB_DNODE_EXIT(db);
2402744947dcSTom Erickson 
24030e8c6158Smaybee 		if (*datap != db->db.db_data) {
2404ea8dc4b6Seschrock 			zio_buf_free(*datap, DN_MAX_BONUSLEN);
24055a98e54bSBrendan Gregg - Sun Microsystems 			arc_space_return(DN_MAX_BONUSLEN, ARC_SPACE_OTHER);
24060e8c6158Smaybee 		}
2407ea8dc4b6Seschrock 		db->db_data_pending = NULL;
2408c717a561Smaybee 		drp = &db->db_last_dirty;
2409c717a561Smaybee 		while (*drp != dr)
2410c717a561Smaybee 			drp = &(*drp)->dr_next;
241117f17c2dSbonwick 		ASSERT(dr->dr_next == NULL);
2412b24ab676SJeff Bonwick 		ASSERT(dr->dr_dbuf == db);
241317f17c2dSbonwick 		*drp = dr->dr_next;
2414c717a561Smaybee 		kmem_free(dr, sizeof (dbuf_dirty_record_t));
2415ea8dc4b6Seschrock 		ASSERT(db->db_dirtycnt > 0);
2416ea8dc4b6Seschrock 		db->db_dirtycnt -= 1;
2417b24ab676SJeff Bonwick 		dbuf_rele_and_unlock(db, (void *)(uintptr_t)txg);
2418ea8dc4b6Seschrock 		return;
2419ea8dc4b6Seschrock 	}
2420ea8dc4b6Seschrock 
2421744947dcSTom Erickson 	os = dn->dn_objset;
2422744947dcSTom Erickson 
2423f82bfe17Sgw 	/*
2424f82bfe17Sgw 	 * This function may have dropped the db_mtx lock allowing a dmu_sync
2425f82bfe17Sgw 	 * operation to sneak in. As a result, we need to ensure that we
2426f82bfe17Sgw 	 * don't check the dr_override_state until we have returned from
2427f82bfe17Sgw 	 * dbuf_check_blkptr.
2428f82bfe17Sgw 	 */
2429f82bfe17Sgw 	dbuf_check_blkptr(dn, db);
2430f82bfe17Sgw 
2431c717a561Smaybee 	/*
2432744947dcSTom Erickson 	 * If this buffer is in the middle of an immediate write,
2433c717a561Smaybee 	 * wait for the synchronous IO to complete.
2434c717a561Smaybee 	 */
2435c717a561Smaybee 	while (dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC) {
2436c717a561Smaybee 		ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT);
2437c717a561Smaybee 		cv_wait(&db->db_changed, &db->db_mtx);
2438c717a561Smaybee 		ASSERT(dr->dt.dl.dr_override_state != DR_NOT_OVERRIDDEN);
2439c717a561Smaybee 	}
2440c5c6ffa0Smaybee 
2441ab69d62fSMatthew Ahrens 	if (db->db_state != DB_NOFILL &&
2442ab69d62fSMatthew Ahrens 	    dn->dn_object != DMU_META_DNODE_OBJECT &&
2443ab69d62fSMatthew Ahrens 	    refcount_count(&db->db_holds) > 1 &&
2444b24ab676SJeff Bonwick 	    dr->dt.dl.dr_override_state != DR_OVERRIDDEN &&
2445ab69d62fSMatthew Ahrens 	    *datap == db->db_buf) {
2446ab69d62fSMatthew Ahrens 		/*
2447ab69d62fSMatthew Ahrens 		 * If this buffer is currently "in use" (i.e., there
2448ab69d62fSMatthew Ahrens 		 * are active holds and db_data still references it),
2449ab69d62fSMatthew Ahrens 		 * then make a copy before we start the write so that
2450ab69d62fSMatthew Ahrens 		 * any modifications from the open txg will not leak
2451ab69d62fSMatthew Ahrens 		 * into this write.
2452ab69d62fSMatthew Ahrens 		 *
2453ab69d62fSMatthew Ahrens 		 * NOTE: this copy does not need to be made for
2454ab69d62fSMatthew Ahrens 		 * objects only modified in the syncing context (e.g.
2455ab69d62fSMatthew Ahrens 		 * DNONE_DNODE blocks).
2456ab69d62fSMatthew Ahrens 		 */
2457ab69d62fSMatthew Ahrens 		int blksz = arc_buf_size(*datap);
2458ab69d62fSMatthew Ahrens 		arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db);
2459ab69d62fSMatthew Ahrens 		*datap = arc_buf_alloc(os->os_spa, blksz, db, type);
2460ab69d62fSMatthew Ahrens 		bcopy(db->db.db_data, (*datap)->b_data, blksz);
246182c9918fSTim Haley 	}
2462c717a561Smaybee 	db->db_data_pending = dr;
2463fa9e4066Sahrens 
2464c717a561Smaybee 	mutex_exit(&db->db_mtx);
2465fa9e4066Sahrens 
2466088f3894Sahrens 	dbuf_write(dr, *datap, tx);
2467fa9e4066Sahrens 
2468c717a561Smaybee 	ASSERT(!list_link_active(&dr->dr_dirty_node));
2469744947dcSTom Erickson 	if (dn->dn_object == DMU_META_DNODE_OBJECT) {
2470c717a561Smaybee 		list_insert_tail(&dn->dn_dirty_records[txg&TXG_MASK], dr);
2471744947dcSTom Erickson 		DB_DNODE_EXIT(db);
2472744947dcSTom Erickson 	} else {
2473744947dcSTom Erickson 		/*
2474744947dcSTom Erickson 		 * Although zio_nowait() does not "wait for an IO", it does
2475744947dcSTom Erickson 		 * initiate the IO. If this is an empty write it seems plausible
2476744947dcSTom Erickson 		 * that the IO could actually be completed before the nowait
2477744947dcSTom Erickson 		 * returns. We need to DB_DNODE_EXIT() first in case
2478744947dcSTom Erickson 		 * zio_nowait() invalidates the dbuf.
2479744947dcSTom Erickson 		 */
2480744947dcSTom Erickson 		DB_DNODE_EXIT(db);
2481c717a561Smaybee 		zio_nowait(dr->dr_zio);
2482744947dcSTom Erickson 	}
2483c717a561Smaybee }
248423b11526Smaybee 
2485c717a561Smaybee void
2486c717a561Smaybee dbuf_sync_list(list_t *list, dmu_tx_t *tx)
2487c717a561Smaybee {
2488c717a561Smaybee 	dbuf_dirty_record_t *dr;
2489c717a561Smaybee 
2490c717a561Smaybee 	while (dr = list_head(list)) {
2491c717a561Smaybee 		if (dr->dr_zio != NULL) {
2492c717a561Smaybee 			/*
2493c717a561Smaybee 			 * If we find an already initialized zio then we
2494c717a561Smaybee 			 * are processing the meta-dnode, and we have finished.
2495c717a561Smaybee 			 * The dbufs for all dnodes are put back on the list
2496c717a561Smaybee 			 * during processing, so that we can zio_wait()
2497c717a561Smaybee 			 * these IOs after initiating all child IOs.
2498c717a561Smaybee 			 */
2499c717a561Smaybee 			ASSERT3U(dr->dr_dbuf->db.db_object, ==,
2500c717a561Smaybee 			    DMU_META_DNODE_OBJECT);
2501c717a561Smaybee 			break;
250223b11526Smaybee 		}
2503c717a561Smaybee 		list_remove(list, dr);
2504c717a561Smaybee 		if (dr->dr_dbuf->db_level > 0)
2505c717a561Smaybee 			dbuf_sync_indirect(dr, tx);
2506c717a561Smaybee 		else
2507c717a561Smaybee 			dbuf_sync_leaf(dr, tx);
250823b11526Smaybee 	}
2509c717a561Smaybee }
251023b11526Smaybee 
2511fa9e4066Sahrens /* ARGSUSED */
2512fa9e4066Sahrens static void
2513c717a561Smaybee dbuf_write_ready(zio_t *zio, arc_buf_t *buf, void *vdb)
2514fa9e4066Sahrens {
2515fa9e4066Sahrens 	dmu_buf_impl_t *db = vdb;
2516744947dcSTom Erickson 	dnode_t *dn;
2517e14bb325SJeff Bonwick 	blkptr_t *bp = zio->io_bp;
2518c717a561Smaybee 	blkptr_t *bp_orig = &zio->io_bp_orig;
2519b24ab676SJeff Bonwick 	spa_t *spa = zio->io_spa;
2520b24ab676SJeff Bonwick 	int64_t delta;
2521fa9e4066Sahrens 	uint64_t fill = 0;
2522b24ab676SJeff Bonwick 	int i;
2523fa9e4066Sahrens 
25245d7b4d43SMatthew Ahrens 	ASSERT3P(db->db_blkptr, ==, bp);
2525e14bb325SJeff Bonwick 
2526744947dcSTom Erickson 	DB_DNODE_ENTER(db);
2527744947dcSTom Erickson 	dn = DB_DNODE(db);
2528b24ab676SJeff Bonwick 	delta = bp_get_dsize_sync(spa, bp) - bp_get_dsize_sync(spa, bp_orig);
2529b24ab676SJeff Bonwick 	dnode_diduse_space(dn, delta - zio->io_prev_space_delta);
2530b24ab676SJeff Bonwick 	zio->io_prev_space_delta = delta;
2531fa9e4066Sahrens 
253243466aaeSMax Grossman 	if (bp->blk_birth != 0) {
253343466aaeSMax Grossman 		ASSERT((db->db_blkid != DMU_SPILL_BLKID &&
253443466aaeSMax Grossman 		    BP_GET_TYPE(bp) == dn->dn_type) ||
253543466aaeSMax Grossman 		    (db->db_blkid == DMU_SPILL_BLKID &&
25365d7b4d43SMatthew Ahrens 		    BP_GET_TYPE(bp) == dn->dn_bonustype) ||
25375d7b4d43SMatthew Ahrens 		    BP_IS_EMBEDDED(bp));
253843466aaeSMax Grossman 		ASSERT(BP_GET_LEVEL(bp) == db->db_level);
2539c717a561Smaybee 	}
2540c5c6ffa0Smaybee 
2541c717a561Smaybee 	mutex_enter(&db->db_mtx);
2542fa9e4066Sahrens 
25430a586ceaSMark Shellenbaum #ifdef ZFS_DEBUG
25440a586ceaSMark Shellenbaum 	if (db->db_blkid == DMU_SPILL_BLKID) {
25450a586ceaSMark Shellenbaum 		ASSERT(dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR);
25460a586ceaSMark Shellenbaum 		ASSERT(!(BP_IS_HOLE(db->db_blkptr)) &&
25470a586ceaSMark Shellenbaum 		    db->db_blkptr == &dn->dn_phys->dn_spill);
25480a586ceaSMark Shellenbaum 	}
25490a586ceaSMark Shellenbaum #endif
25500a586ceaSMark Shellenbaum 
2551fa9e4066Sahrens 	if (db->db_level == 0) {
2552fa9e4066Sahrens 		mutex_enter(&dn->dn_mtx);
25530a586ceaSMark Shellenbaum 		if (db->db_blkid > dn->dn_phys->dn_maxblkid &&
25540a586ceaSMark Shellenbaum 		    db->db_blkid != DMU_SPILL_BLKID)
2555fa9e4066Sahrens 			dn->dn_phys->dn_maxblkid = db->db_blkid;
2556fa9e4066Sahrens 		mutex_exit(&dn->dn_mtx);
2557fa9e4066Sahrens 
2558fa9e4066Sahrens 		if (dn->dn_type == DMU_OT_DNODE) {
2559fa9e4066Sahrens 			dnode_phys_t *dnp = db->db.db_data;
2560fa9e4066Sahrens 			for (i = db->db.db_size >> DNODE_SHIFT; i > 0;
2561fa9e4066Sahrens 			    i--, dnp++) {
2562fa9e4066Sahrens 				if (dnp->dn_type != DMU_OT_NONE)
2563fa9e4066Sahrens 					fill++;
2564fa9e4066Sahrens 			}
2565fa9e4066Sahrens 		} else {
256643466aaeSMax Grossman 			if (BP_IS_HOLE(bp)) {
256743466aaeSMax Grossman 				fill = 0;
256843466aaeSMax Grossman 			} else {
256943466aaeSMax Grossman 				fill = 1;
257043466aaeSMax Grossman 			}
2571fa9e4066Sahrens 		}
2572fa9e4066Sahrens 	} else {
2573e14bb325SJeff Bonwick 		blkptr_t *ibp = db->db.db_data;
2574fa9e4066Sahrens 		ASSERT3U(db->db.db_size, ==, 1<<dn->dn_phys->dn_indblkshift);
2575e14bb325SJeff Bonwick 		for (i = db->db.db_size >> SPA_BLKPTRSHIFT; i > 0; i--, ibp++) {
2576e14bb325SJeff Bonwick 			if (BP_IS_HOLE(ibp))
2577fa9e4066Sahrens 				continue;
25785d7b4d43SMatthew Ahrens 			fill += BP_GET_FILL(ibp);
2579fa9e4066Sahrens 		}
2580fa9e4066Sahrens 	}
2581744947dcSTom Erickson 	DB_DNODE_EXIT(db);
2582fa9e4066Sahrens 
25835d7b4d43SMatthew Ahrens 	if (!BP_IS_EMBEDDED(bp))
25845d7b4d43SMatthew Ahrens 		bp->blk_fill = fill;
2585c717a561Smaybee 
2586c717a561Smaybee 	mutex_exit(&db->db_mtx);
2587c717a561Smaybee }
2588fa9e4066Sahrens 
258969962b56SMatthew Ahrens /*
259069962b56SMatthew Ahrens  * The SPA will call this callback several times for each zio - once
259169962b56SMatthew Ahrens  * for every physical child i/o (zio->io_phys_children times).  This
259269962b56SMatthew Ahrens  * allows the DMU to monitor the progress of each logical i/o.  For example,
259369962b56SMatthew Ahrens  * there may be 2 copies of an indirect block, or many fragments of a RAID-Z
259469962b56SMatthew Ahrens  * block.  There may be a long delay before all copies/fragments are completed,
259569962b56SMatthew Ahrens  * so this callback allows us to retire dirty space gradually, as the physical
259669962b56SMatthew Ahrens  * i/os complete.
259769962b56SMatthew Ahrens  */
259869962b56SMatthew Ahrens /* ARGSUSED */
259969962b56SMatthew Ahrens static void
260069962b56SMatthew Ahrens dbuf_write_physdone(zio_t *zio, arc_buf_t *buf, void *arg)
260169962b56SMatthew Ahrens {
260269962b56SMatthew Ahrens 	dmu_buf_impl_t *db = arg;
260369962b56SMatthew Ahrens 	objset_t *os = db->db_objset;
260469962b56SMatthew Ahrens 	dsl_pool_t *dp = dmu_objset_pool(os);
260569962b56SMatthew Ahrens 	dbuf_dirty_record_t *dr;
260669962b56SMatthew Ahrens 	int delta = 0;
260769962b56SMatthew Ahrens 
260869962b56SMatthew Ahrens 	dr = db->db_data_pending;
260969962b56SMatthew Ahrens 	ASSERT3U(dr->dr_txg, ==, zio->io_txg);
261069962b56SMatthew Ahrens 
261169962b56SMatthew Ahrens 	/*
261269962b56SMatthew Ahrens 	 * The callback will be called io_phys_children times.  Retire one
261369962b56SMatthew Ahrens 	 * portion of our dirty space each time we are called.  Any rounding
261469962b56SMatthew Ahrens 	 * error will be cleaned up by dsl_pool_sync()'s call to
261569962b56SMatthew Ahrens 	 * dsl_pool_undirty_space().
261669962b56SMatthew Ahrens 	 */
261769962b56SMatthew Ahrens 	delta = dr->dr_accounted / zio->io_phys_children;
261869962b56SMatthew Ahrens 	dsl_pool_undirty_space(dp, delta, zio->io_txg);
261969962b56SMatthew Ahrens }
262069962b56SMatthew Ahrens 
2621c717a561Smaybee /* ARGSUSED */
2622c717a561Smaybee static void
2623c717a561Smaybee dbuf_write_done(zio_t *zio, arc_buf_t *buf, void *vdb)
2624c717a561Smaybee {
2625c717a561Smaybee 	dmu_buf_impl_t *db = vdb;
2626b24ab676SJeff Bonwick 	blkptr_t *bp_orig = &zio->io_bp_orig;
262743466aaeSMax Grossman 	blkptr_t *bp = db->db_blkptr;
262843466aaeSMax Grossman 	objset_t *os = db->db_objset;
262943466aaeSMax Grossman 	dmu_tx_t *tx = os->os_synctx;
2630c717a561Smaybee 	dbuf_dirty_record_t **drp, *dr;
2631c717a561Smaybee 
2632fb09f5aaSMadhav Suresh 	ASSERT0(zio->io_error);
2633b24ab676SJeff Bonwick 	ASSERT(db->db_blkptr == bp);
2634b24ab676SJeff Bonwick 
263580901aeaSGeorge Wilson 	/*
263680901aeaSGeorge Wilson 	 * For nopwrites and rewrites we ensure that the bp matches our
263780901aeaSGeorge Wilson 	 * original and bypass all the accounting.
263880901aeaSGeorge Wilson 	 */
263980901aeaSGeorge Wilson 	if (zio->io_flags & (ZIO_FLAG_IO_REWRITE | ZIO_FLAG_NOPWRITE)) {
2640b24ab676SJeff Bonwick 		ASSERT(BP_EQUAL(bp, bp_orig));
2641b24ab676SJeff Bonwick 	} else {
264243466aaeSMax Grossman 		dsl_dataset_t *ds = os->os_dsl_dataset;
2643b24ab676SJeff Bonwick 		(void) dsl_dataset_block_kill(ds, bp_orig, tx, B_TRUE);
2644b24ab676SJeff Bonwick 		dsl_dataset_block_born(ds, bp, tx);
2645b24ab676SJeff Bonwick 	}
2646c717a561Smaybee 
2647c717a561Smaybee 	mutex_enter(&db->db_mtx);
2648c717a561Smaybee 
2649b24ab676SJeff Bonwick 	DBUF_VERIFY(db);
2650b24ab676SJeff Bonwick 
2651c717a561Smaybee 	drp = &db->db_last_dirty;
265217f17c2dSbonwick 	while ((dr = *drp) != db->db_data_pending)
265317f17c2dSbonwick 		drp = &dr->dr_next;
265417f17c2dSbonwick 	ASSERT(!list_link_active(&dr->dr_dirty_node));
2655b24ab676SJeff Bonwick 	ASSERT(dr->dr_dbuf == db);
265617f17c2dSbonwick 	ASSERT(dr->dr_next == NULL);
265717f17c2dSbonwick 	*drp = dr->dr_next;
2658c717a561Smaybee 
26590a586ceaSMark Shellenbaum #ifdef ZFS_DEBUG
26600a586ceaSMark Shellenbaum 	if (db->db_blkid == DMU_SPILL_BLKID) {
2661744947dcSTom Erickson 		dnode_t *dn;
2662744947dcSTom Erickson 
2663744947dcSTom Erickson 		DB_DNODE_ENTER(db);
2664744947dcSTom Erickson 		dn = DB_DNODE(db);
26650a586ceaSMark Shellenbaum 		ASSERT(dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR);
26660a586ceaSMark Shellenbaum 		ASSERT(!(BP_IS_HOLE(db->db_blkptr)) &&
26670a586ceaSMark Shellenbaum 		    db->db_blkptr == &dn->dn_phys->dn_spill);
2668744947dcSTom Erickson 		DB_DNODE_EXIT(db);
26690a586ceaSMark Shellenbaum 	}
26700a586ceaSMark Shellenbaum #endif
26710a586ceaSMark Shellenbaum 
2672c717a561Smaybee 	if (db->db_level == 0) {
26730a586ceaSMark Shellenbaum 		ASSERT(db->db_blkid != DMU_BONUS_BLKID);
2674c717a561Smaybee 		ASSERT(dr->dt.dl.dr_override_state == DR_NOT_OVERRIDDEN);
267582c9918fSTim Haley 		if (db->db_state != DB_NOFILL) {
267682c9918fSTim Haley 			if (dr->dt.dl.dr_data != db->db_buf)
267782c9918fSTim Haley 				VERIFY(arc_buf_remove_ref(dr->dt.dl.dr_data,
26783b2aab18SMatthew Ahrens 				    db));
2679b24ab676SJeff Bonwick 			else if (!arc_released(db->db_buf))
268082c9918fSTim Haley 				arc_set_callback(db->db_buf, dbuf_do_evict, db);
268182c9918fSTim Haley 		}
2682c717a561Smaybee 	} else {
2683744947dcSTom Erickson 		dnode_t *dn;
2684744947dcSTom Erickson 
2685744947dcSTom Erickson 		DB_DNODE_ENTER(db);
2686744947dcSTom Erickson 		dn = DB_DNODE(db);
2687c717a561Smaybee 		ASSERT(list_head(&dr->dt.di.dr_children) == NULL);
268843466aaeSMax Grossman 		ASSERT3U(db->db.db_size, ==, 1 << dn->dn_phys->dn_indblkshift);
2689c717a561Smaybee 		if (!BP_IS_HOLE(db->db_blkptr)) {
2690c717a561Smaybee 			int epbs =
2691c717a561Smaybee 			    dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
269243466aaeSMax Grossman 			ASSERT3U(db->db_blkid, <=,
269343466aaeSMax Grossman 			    dn->dn_phys->dn_maxblkid >> (db->db_level * epbs));
2694c717a561Smaybee 			ASSERT3U(BP_GET_LSIZE(db->db_blkptr), ==,
2695c717a561Smaybee 			    db->db.db_size);
26965d7b4d43SMatthew Ahrens 			if (!arc_released(db->db_buf))
26975d7b4d43SMatthew Ahrens 				arc_set_callback(db->db_buf, dbuf_do_evict, db);
2698c717a561Smaybee 		}
2699744947dcSTom Erickson 		DB_DNODE_EXIT(db);
2700c25056deSgw 		mutex_destroy(&dr->dt.di.dr_mtx);
2701c25056deSgw 		list_destroy(&dr->dt.di.dr_children);
2702c717a561Smaybee 	}
2703c717a561Smaybee 	kmem_free(dr, sizeof (dbuf_dirty_record_t));
2704fa9e4066Sahrens 
2705fa9e4066Sahrens 	cv_broadcast(&db->db_changed);
2706fa9e4066Sahrens 	ASSERT(db->db_dirtycnt > 0);
2707fa9e4066Sahrens 	db->db_dirtycnt -= 1;
2708c717a561Smaybee 	db->db_data_pending = NULL;
270943466aaeSMax Grossman 	dbuf_rele_and_unlock(db, (void *)(uintptr_t)tx->tx_txg);
2710b24ab676SJeff Bonwick }
2711b24ab676SJeff Bonwick 
2712b24ab676SJeff Bonwick static void
2713b24ab676SJeff Bonwick dbuf_write_nofill_ready(zio_t *zio)
2714b24ab676SJeff Bonwick {
2715b24ab676SJeff Bonwick 	dbuf_write_ready(zio, NULL, zio->io_private);
2716b24ab676SJeff Bonwick }
2717b24ab676SJeff Bonwick 
2718b24ab676SJeff Bonwick static void
2719b24ab676SJeff Bonwick dbuf_write_nofill_done(zio_t *zio)
2720b24ab676SJeff Bonwick {
2721b24ab676SJeff Bonwick 	dbuf_write_done(zio, NULL, zio->io_private);
2722b24ab676SJeff Bonwick }
2723b24ab676SJeff Bonwick 
2724b24ab676SJeff Bonwick static void
2725b24ab676SJeff Bonwick dbuf_write_override_ready(zio_t *zio)
2726b24ab676SJeff Bonwick {
2727b24ab676SJeff Bonwick 	dbuf_dirty_record_t *dr = zio->io_private;
2728b24ab676SJeff Bonwick 	dmu_buf_impl_t *db = dr->dr_dbuf;
2729b24ab676SJeff Bonwick 
2730b24ab676SJeff Bonwick 	dbuf_write_ready(zio, NULL, db);
2731b24ab676SJeff Bonwick }
2732b24ab676SJeff Bonwick 
2733b24ab676SJeff Bonwick static void
2734b24ab676SJeff Bonwick dbuf_write_override_done(zio_t *zio)
2735b24ab676SJeff Bonwick {
2736b24ab676SJeff Bonwick 	dbuf_dirty_record_t *dr = zio->io_private;
2737b24ab676SJeff Bonwick 	dmu_buf_impl_t *db = dr->dr_dbuf;
2738b24ab676SJeff Bonwick 	blkptr_t *obp = &dr->dt.dl.dr_overridden_by;
2739b24ab676SJeff Bonwick 
2740b24ab676SJeff Bonwick 	mutex_enter(&db->db_mtx);
2741b24ab676SJeff Bonwick 	if (!BP_EQUAL(zio->io_bp, obp)) {
2742b24ab676SJeff Bonwick 		if (!BP_IS_HOLE(obp))
2743b24ab676SJeff Bonwick 			dsl_free(spa_get_dsl(zio->io_spa), zio->io_txg, obp);
2744b24ab676SJeff Bonwick 		arc_release(dr->dt.dl.dr_data, db);
2745b24ab676SJeff Bonwick 	}
2746fa9e4066Sahrens 	mutex_exit(&db->db_mtx);
2747fa9e4066Sahrens 
2748b24ab676SJeff Bonwick 	dbuf_write_done(zio, NULL, db);
2749b24ab676SJeff Bonwick }
2750b24ab676SJeff Bonwick 
27513e30c24aSWill Andrews /* Issue I/O to commit a dirty buffer to disk. */
2752b24ab676SJeff Bonwick static void
2753b24ab676SJeff Bonwick dbuf_write(dbuf_dirty_record_t *dr, arc_buf_t *data, dmu_tx_t *tx)
2754b24ab676SJeff Bonwick {
2755b24ab676SJeff Bonwick 	dmu_buf_impl_t *db = dr->dr_dbuf;
2756744947dcSTom Erickson 	dnode_t *dn;
2757744947dcSTom Erickson 	objset_t *os;
2758b24ab676SJeff Bonwick 	dmu_buf_impl_t *parent = db->db_parent;
2759b24ab676SJeff Bonwick 	uint64_t txg = tx->tx_txg;
27607802d7bfSMatthew Ahrens 	zbookmark_phys_t zb;
2761b24ab676SJeff Bonwick 	zio_prop_t zp;
2762b24ab676SJeff Bonwick 	zio_t *zio;
27630a586ceaSMark Shellenbaum 	int wp_flag = 0;
2764b24ab676SJeff Bonwick 
2765744947dcSTom Erickson 	DB_DNODE_ENTER(db);
2766744947dcSTom Erickson 	dn = DB_DNODE(db);
2767744947dcSTom Erickson 	os = dn->dn_objset;
2768744947dcSTom Erickson 
2769b24ab676SJeff Bonwick 	if (db->db_state != DB_NOFILL) {
2770b24ab676SJeff Bonwick 		if (db->db_level > 0 || dn->dn_type == DMU_OT_DNODE) {
2771b24ab676SJeff Bonwick 			/*
2772b24ab676SJeff Bonwick 			 * Private object buffers are released here rather
2773b24ab676SJeff Bonwick 			 * than in dbuf_dirty() since they are only modified
2774b24ab676SJeff Bonwick 			 * in the syncing context and we don't want the
2775b24ab676SJeff Bonwick 			 * overhead of making multiple copies of the data.
2776b24ab676SJeff Bonwick 			 */
2777b24ab676SJeff Bonwick 			if (BP_IS_HOLE(db->db_blkptr)) {
2778b24ab676SJeff Bonwick 				arc_buf_thaw(data);
2779b24ab676SJeff Bonwick 			} else {
27803f9d6ad7SLin Ling 				dbuf_release_bp(db);
2781b24ab676SJeff Bonwick 			}
2782b24ab676SJeff Bonwick 		}
2783b24ab676SJeff Bonwick 	}
2784b24ab676SJeff Bonwick 
2785b24ab676SJeff Bonwick 	if (parent != dn->dn_dbuf) {
27863e30c24aSWill Andrews 		/* Our parent is an indirect block. */
27873e30c24aSWill Andrews 		/* We have a dirty parent that has been scheduled for write. */
2788b24ab676SJeff Bonwick 		ASSERT(parent && parent->db_data_pending);
27893e30c24aSWill Andrews 		/* Our parent's buffer is one level closer to the dnode. */
2790b24ab676SJeff Bonwick 		ASSERT(db->db_level == parent->db_level-1);
27913e30c24aSWill Andrews 		/*
27923e30c24aSWill Andrews 		 * We're about to modify our parent's db_data by modifying
27933e30c24aSWill Andrews 		 * our block pointer, so the parent must be released.
27943e30c24aSWill Andrews 		 */
2795b24ab676SJeff Bonwick 		ASSERT(arc_released(parent->db_buf));
2796b24ab676SJeff Bonwick 		zio = parent->db_data_pending->dr_zio;
2797b24ab676SJeff Bonwick 	} else {
27983e30c24aSWill Andrews 		/* Our parent is the dnode itself. */
27990a586ceaSMark Shellenbaum 		ASSERT((db->db_level == dn->dn_phys->dn_nlevels-1 &&
28000a586ceaSMark Shellenbaum 		    db->db_blkid != DMU_SPILL_BLKID) ||
28010a586ceaSMark Shellenbaum 		    (db->db_blkid == DMU_SPILL_BLKID && db->db_level == 0));
28020a586ceaSMark Shellenbaum 		if (db->db_blkid != DMU_SPILL_BLKID)
28030a586ceaSMark Shellenbaum 			ASSERT3P(db->db_blkptr, ==,
28040a586ceaSMark Shellenbaum 			    &dn->dn_phys->dn_blkptr[db->db_blkid]);
2805b24ab676SJeff Bonwick 		zio = dn->dn_zio;
2806b24ab676SJeff Bonwick 	}
2807b24ab676SJeff Bonwick 
2808b24ab676SJeff Bonwick 	ASSERT(db->db_level == 0 || data == db->db_buf);
2809b24ab676SJeff Bonwick 	ASSERT3U(db->db_blkptr->blk_birth, <=, txg);
2810b24ab676SJeff Bonwick 	ASSERT(zio);
2811fa9e4066Sahrens 
2812b24ab676SJeff Bonwick 	SET_BOOKMARK(&zb, os->os_dsl_dataset ?
2813b24ab676SJeff Bonwick 	    os->os_dsl_dataset->ds_object : DMU_META_OBJSET,
2814b24ab676SJeff Bonwick 	    db->db.db_object, db->db_level, db->db_blkid);
2815b24ab676SJeff Bonwick 
28160a586ceaSMark Shellenbaum 	if (db->db_blkid == DMU_SPILL_BLKID)
28170a586ceaSMark Shellenbaum 		wp_flag = WP_SPILL;
28180a586ceaSMark Shellenbaum 	wp_flag |= (db->db_state == DB_NOFILL) ? WP_NOFILL : 0;
28190a586ceaSMark Shellenbaum 
28200a586ceaSMark Shellenbaum 	dmu_write_policy(os, dn, db->db_level, wp_flag, &zp);
2821744947dcSTom Erickson 	DB_DNODE_EXIT(db);
2822b24ab676SJeff Bonwick 
28235d7b4d43SMatthew Ahrens 	if (db->db_level == 0 &&
28245d7b4d43SMatthew Ahrens 	    dr->dt.dl.dr_override_state == DR_OVERRIDDEN) {
28255d7b4d43SMatthew Ahrens 		/*
28265d7b4d43SMatthew Ahrens 		 * The BP for this block has been provided by open context
28275d7b4d43SMatthew Ahrens 		 * (by dmu_sync() or dmu_buf_write_embedded()).
28285d7b4d43SMatthew Ahrens 		 */
28295d7b4d43SMatthew Ahrens 		void *contents = (data != NULL) ? data->b_data : NULL;
28305d7b4d43SMatthew Ahrens 
2831b24ab676SJeff Bonwick 		dr->dr_zio = zio_write(zio, os->os_spa, txg,
28325d7b4d43SMatthew Ahrens 		    db->db_blkptr, contents, db->db.db_size, &zp,
283369962b56SMatthew Ahrens 		    dbuf_write_override_ready, NULL, dbuf_write_override_done,
283469962b56SMatthew Ahrens 		    dr, ZIO_PRIORITY_ASYNC_WRITE, ZIO_FLAG_MUSTSUCCEED, &zb);
2835b24ab676SJeff Bonwick 		mutex_enter(&db->db_mtx);
2836b24ab676SJeff Bonwick 		dr->dt.dl.dr_override_state = DR_NOT_OVERRIDDEN;
2837b24ab676SJeff Bonwick 		zio_write_override(dr->dr_zio, &dr->dt.dl.dr_overridden_by,
283880901aeaSGeorge Wilson 		    dr->dt.dl.dr_copies, dr->dt.dl.dr_nopwrite);
2839b24ab676SJeff Bonwick 		mutex_exit(&db->db_mtx);
2840b24ab676SJeff Bonwick 	} else if (db->db_state == DB_NOFILL) {
2841810e43b2SBill Pijewski 		ASSERT(zp.zp_checksum == ZIO_CHECKSUM_OFF ||
2842810e43b2SBill Pijewski 		    zp.zp_checksum == ZIO_CHECKSUM_NOPARITY);
2843b24ab676SJeff Bonwick 		dr->dr_zio = zio_write(zio, os->os_spa, txg,
2844b24ab676SJeff Bonwick 		    db->db_blkptr, NULL, db->db.db_size, &zp,
284569962b56SMatthew Ahrens 		    dbuf_write_nofill_ready, NULL, dbuf_write_nofill_done, db,
2846b24ab676SJeff Bonwick 		    ZIO_PRIORITY_ASYNC_WRITE,
2847b24ab676SJeff Bonwick 		    ZIO_FLAG_MUSTSUCCEED | ZIO_FLAG_NODATA, &zb);
2848b24ab676SJeff Bonwick 	} else {
2849b24ab676SJeff Bonwick 		ASSERT(arc_released(data));
2850b24ab676SJeff Bonwick 		dr->dr_zio = arc_write(zio, os->os_spa, txg,
2851aad02571SSaso Kiselkov 		    db->db_blkptr, data, DBUF_IS_L2CACHEABLE(db),
2852aad02571SSaso Kiselkov 		    DBUF_IS_L2COMPRESSIBLE(db), &zp, dbuf_write_ready,
285369962b56SMatthew Ahrens 		    dbuf_write_physdone, dbuf_write_done, db,
285469962b56SMatthew Ahrens 		    ZIO_PRIORITY_ASYNC_WRITE, ZIO_FLAG_MUSTSUCCEED, &zb);
2855b24ab676SJeff Bonwick 	}
2856fa9e4066Sahrens }
2857