xref: /freebsd-src/sys/contrib/openzfs/include/sys/dmu.h (revision ce4dcb97ca433b2a2f03fbae957dae0ff16f6f51)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or https://opensource.org/licenses/CDDL-1.0.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23  * Copyright (c) 2011, 2020 by Delphix. All rights reserved.
24  * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
25  * Copyright (c) 2012, Joyent, Inc. All rights reserved.
26  * Copyright 2014 HybridCluster. All rights reserved.
27  * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
28  * Copyright 2013 Saso Kiselkov. All rights reserved.
29  * Copyright (c) 2017, Intel Corporation.
30  * Copyright (c) 2022 Hewlett Packard Enterprise Development LP.
31  */
32 
33 /* Portions Copyright 2010 Robert Milkowski */
34 
35 #ifndef	_SYS_DMU_H
36 #define	_SYS_DMU_H
37 
38 /*
39  * This file describes the interface that the DMU provides for its
40  * consumers.
41  *
42  * The DMU also interacts with the SPA.  That interface is described in
43  * dmu_spa.h.
44  */
45 
46 #include <sys/zfs_context.h>
47 #include <sys/inttypes.h>
48 #include <sys/cred.h>
49 #include <sys/fs/zfs.h>
50 #include <sys/zio_compress.h>
51 #include <sys/zio_priority.h>
52 #include <sys/uio.h>
53 #include <sys/zfs_file.h>
54 
55 #ifdef	__cplusplus
56 extern "C" {
57 #endif
58 
59 struct page;
60 struct vnode;
61 struct spa;
62 struct zilog;
63 struct zio;
64 struct blkptr;
65 struct zap_cursor;
66 struct dsl_dataset;
67 struct dsl_pool;
68 struct dnode;
69 struct drr_begin;
70 struct drr_end;
71 struct zbookmark_phys;
72 struct spa;
73 struct nvlist;
74 struct arc_buf;
75 struct zio_prop;
76 struct sa_handle;
77 struct dsl_crypto_params;
78 struct locked_range;
79 
80 typedef struct objset objset_t;
81 typedef struct dmu_tx dmu_tx_t;
82 typedef struct dsl_dir dsl_dir_t;
83 typedef struct dnode dnode_t;
84 
85 typedef enum dmu_object_byteswap {
86 	DMU_BSWAP_UINT8,
87 	DMU_BSWAP_UINT16,
88 	DMU_BSWAP_UINT32,
89 	DMU_BSWAP_UINT64,
90 	DMU_BSWAP_ZAP,
91 	DMU_BSWAP_DNODE,
92 	DMU_BSWAP_OBJSET,
93 	DMU_BSWAP_ZNODE,
94 	DMU_BSWAP_OLDACL,
95 	DMU_BSWAP_ACL,
96 	/*
97 	 * Allocating a new byteswap type number makes the on-disk format
98 	 * incompatible with any other format that uses the same number.
99 	 *
100 	 * Data can usually be structured to work with one of the
101 	 * DMU_BSWAP_UINT* or DMU_BSWAP_ZAP types.
102 	 */
103 	DMU_BSWAP_NUMFUNCS
104 } dmu_object_byteswap_t;
105 
106 #define	DMU_OT_NEWTYPE 0x80
107 #define	DMU_OT_METADATA 0x40
108 #define	DMU_OT_ENCRYPTED 0x20
109 #define	DMU_OT_BYTESWAP_MASK 0x1f
110 
111 /*
112  * Defines a uint8_t object type. Object types specify if the data
113  * in the object is metadata (boolean) and how to byteswap the data
114  * (dmu_object_byteswap_t). All of the types created by this method
115  * are cached in the dbuf metadata cache.
116  */
117 #define	DMU_OT(byteswap, metadata, encrypted) \
118 	(DMU_OT_NEWTYPE | \
119 	((metadata) ? DMU_OT_METADATA : 0) | \
120 	((encrypted) ? DMU_OT_ENCRYPTED : 0) | \
121 	((byteswap) & DMU_OT_BYTESWAP_MASK))
122 
123 #define	DMU_OT_IS_VALID(ot) (((ot) & DMU_OT_NEWTYPE) ? \
124 	((ot) & DMU_OT_BYTESWAP_MASK) < DMU_BSWAP_NUMFUNCS : \
125 	(ot) < DMU_OT_NUMTYPES)
126 
127 #define	DMU_OT_IS_METADATA_CACHED(ot) (((ot) & DMU_OT_NEWTYPE) ? \
128 	B_TRUE : dmu_ot[(ot)].ot_dbuf_metadata_cache)
129 
130 /*
131  * MDB doesn't have dmu_ot; it defines these macros itself.
132  */
133 #ifndef ZFS_MDB
134 #define	DMU_OT_IS_METADATA_IMPL(ot) (dmu_ot[ot].ot_metadata)
135 #define	DMU_OT_IS_ENCRYPTED_IMPL(ot) (dmu_ot[ot].ot_encrypt)
136 #define	DMU_OT_BYTESWAP_IMPL(ot) (dmu_ot[ot].ot_byteswap)
137 #endif
138 
139 #define	DMU_OT_IS_METADATA(ot) (((ot) & DMU_OT_NEWTYPE) ? \
140 	(((ot) & DMU_OT_METADATA) != 0) : \
141 	DMU_OT_IS_METADATA_IMPL(ot))
142 
143 #define	DMU_OT_IS_DDT(ot) \
144 	((ot) == DMU_OT_DDT_ZAP)
145 
146 #define	DMU_OT_IS_CRITICAL(ot) \
147 	(DMU_OT_IS_METADATA(ot) && \
148 	(ot) != DMU_OT_DNODE && \
149 	(ot) != DMU_OT_DIRECTORY_CONTENTS && \
150 	(ot) != DMU_OT_SA)
151 
152 /* Note: ztest uses DMU_OT_UINT64_OTHER as a proxy for file blocks */
153 #define	DMU_OT_IS_FILE(ot) \
154 	((ot) == DMU_OT_PLAIN_FILE_CONTENTS || (ot) == DMU_OT_UINT64_OTHER)
155 
156 #define	DMU_OT_IS_ENCRYPTED(ot) (((ot) & DMU_OT_NEWTYPE) ? \
157 	(((ot) & DMU_OT_ENCRYPTED) != 0) : \
158 	DMU_OT_IS_ENCRYPTED_IMPL(ot))
159 
160 /*
161  * These object types use bp_fill != 1 for their L0 bp's. Therefore they can't
162  * have their data embedded (i.e. use a BP_IS_EMBEDDED() bp), because bp_fill
163  * is repurposed for embedded BPs.
164  */
165 #define	DMU_OT_HAS_FILL(ot) \
166 	((ot) == DMU_OT_DNODE || (ot) == DMU_OT_OBJSET)
167 
168 #define	DMU_OT_BYTESWAP(ot) (((ot) & DMU_OT_NEWTYPE) ? \
169 	((ot) & DMU_OT_BYTESWAP_MASK) : \
170 	DMU_OT_BYTESWAP_IMPL(ot))
171 
172 typedef enum dmu_object_type {
173 	DMU_OT_NONE,
174 	/* general: */
175 	DMU_OT_OBJECT_DIRECTORY,	/* ZAP */
176 	DMU_OT_OBJECT_ARRAY,		/* UINT64 */
177 	DMU_OT_PACKED_NVLIST,		/* UINT8 (XDR by nvlist_pack/unpack) */
178 	DMU_OT_PACKED_NVLIST_SIZE,	/* UINT64 */
179 	DMU_OT_BPOBJ,			/* UINT64 */
180 	DMU_OT_BPOBJ_HDR,		/* UINT64 */
181 	/* spa: */
182 	DMU_OT_SPACE_MAP_HEADER,	/* UINT64 */
183 	DMU_OT_SPACE_MAP,		/* UINT64 */
184 	/* zil: */
185 	DMU_OT_INTENT_LOG,		/* UINT64 */
186 	/* dmu: */
187 	DMU_OT_DNODE,			/* DNODE */
188 	DMU_OT_OBJSET,			/* OBJSET */
189 	/* dsl: */
190 	DMU_OT_DSL_DIR,			/* UINT64 */
191 	DMU_OT_DSL_DIR_CHILD_MAP,	/* ZAP */
192 	DMU_OT_DSL_DS_SNAP_MAP,		/* ZAP */
193 	DMU_OT_DSL_PROPS,		/* ZAP */
194 	DMU_OT_DSL_DATASET,		/* UINT64 */
195 	/* zpl: */
196 	DMU_OT_ZNODE,			/* ZNODE */
197 	DMU_OT_OLDACL,			/* Old ACL */
198 	DMU_OT_PLAIN_FILE_CONTENTS,	/* UINT8 */
199 	DMU_OT_DIRECTORY_CONTENTS,	/* ZAP */
200 	DMU_OT_MASTER_NODE,		/* ZAP */
201 	DMU_OT_UNLINKED_SET,		/* ZAP */
202 	/* zvol: */
203 	DMU_OT_ZVOL,			/* UINT8 */
204 	DMU_OT_ZVOL_PROP,		/* ZAP */
205 	/* other; for testing only! */
206 	DMU_OT_PLAIN_OTHER,		/* UINT8 */
207 	DMU_OT_UINT64_OTHER,		/* UINT64 */
208 	DMU_OT_ZAP_OTHER,		/* ZAP */
209 	/* new object types: */
210 	DMU_OT_ERROR_LOG,		/* ZAP */
211 	DMU_OT_SPA_HISTORY,		/* UINT8 */
212 	DMU_OT_SPA_HISTORY_OFFSETS,	/* spa_his_phys_t */
213 	DMU_OT_POOL_PROPS,		/* ZAP */
214 	DMU_OT_DSL_PERMS,		/* ZAP */
215 	DMU_OT_ACL,			/* ACL */
216 	DMU_OT_SYSACL,			/* SYSACL */
217 	DMU_OT_FUID,			/* FUID table (Packed NVLIST UINT8) */
218 	DMU_OT_FUID_SIZE,		/* FUID table size UINT64 */
219 	DMU_OT_NEXT_CLONES,		/* ZAP */
220 	DMU_OT_SCAN_QUEUE,		/* ZAP */
221 	DMU_OT_USERGROUP_USED,		/* ZAP */
222 	DMU_OT_USERGROUP_QUOTA,		/* ZAP */
223 	DMU_OT_USERREFS,		/* ZAP */
224 	DMU_OT_DDT_ZAP,			/* ZAP */
225 	DMU_OT_DDT_STATS,		/* ZAP */
226 	DMU_OT_SA,			/* System attr */
227 	DMU_OT_SA_MASTER_NODE,		/* ZAP */
228 	DMU_OT_SA_ATTR_REGISTRATION,	/* ZAP */
229 	DMU_OT_SA_ATTR_LAYOUTS,		/* ZAP */
230 	DMU_OT_SCAN_XLATE,		/* ZAP */
231 	DMU_OT_DEDUP,			/* fake dedup BP from ddt_bp_create() */
232 	DMU_OT_DEADLIST,		/* ZAP */
233 	DMU_OT_DEADLIST_HDR,		/* UINT64 */
234 	DMU_OT_DSL_CLONES,		/* ZAP */
235 	DMU_OT_BPOBJ_SUBOBJ,		/* UINT64 */
236 	/*
237 	 * Do not allocate new object types here. Doing so makes the on-disk
238 	 * format incompatible with any other format that uses the same object
239 	 * type number.
240 	 *
241 	 * When creating an object which does not have one of the above types
242 	 * use the DMU_OTN_* type with the correct byteswap and metadata
243 	 * values.
244 	 *
245 	 * The DMU_OTN_* types do not have entries in the dmu_ot table,
246 	 * use the DMU_OT_IS_METADATA() and DMU_OT_BYTESWAP() macros instead
247 	 * of indexing into dmu_ot directly (this works for both DMU_OT_* types
248 	 * and DMU_OTN_* types).
249 	 */
250 	DMU_OT_NUMTYPES,
251 
252 	/*
253 	 * Names for valid types declared with DMU_OT().
254 	 */
255 	DMU_OTN_UINT8_DATA = DMU_OT(DMU_BSWAP_UINT8, B_FALSE, B_FALSE),
256 	DMU_OTN_UINT8_METADATA = DMU_OT(DMU_BSWAP_UINT8, B_TRUE, B_FALSE),
257 	DMU_OTN_UINT16_DATA = DMU_OT(DMU_BSWAP_UINT16, B_FALSE, B_FALSE),
258 	DMU_OTN_UINT16_METADATA = DMU_OT(DMU_BSWAP_UINT16, B_TRUE, B_FALSE),
259 	DMU_OTN_UINT32_DATA = DMU_OT(DMU_BSWAP_UINT32, B_FALSE, B_FALSE),
260 	DMU_OTN_UINT32_METADATA = DMU_OT(DMU_BSWAP_UINT32, B_TRUE, B_FALSE),
261 	DMU_OTN_UINT64_DATA = DMU_OT(DMU_BSWAP_UINT64, B_FALSE, B_FALSE),
262 	DMU_OTN_UINT64_METADATA = DMU_OT(DMU_BSWAP_UINT64, B_TRUE, B_FALSE),
263 	DMU_OTN_ZAP_DATA = DMU_OT(DMU_BSWAP_ZAP, B_FALSE, B_FALSE),
264 	DMU_OTN_ZAP_METADATA = DMU_OT(DMU_BSWAP_ZAP, B_TRUE, B_FALSE),
265 
266 	DMU_OTN_UINT8_ENC_DATA = DMU_OT(DMU_BSWAP_UINT8, B_FALSE, B_TRUE),
267 	DMU_OTN_UINT8_ENC_METADATA = DMU_OT(DMU_BSWAP_UINT8, B_TRUE, B_TRUE),
268 	DMU_OTN_UINT16_ENC_DATA = DMU_OT(DMU_BSWAP_UINT16, B_FALSE, B_TRUE),
269 	DMU_OTN_UINT16_ENC_METADATA = DMU_OT(DMU_BSWAP_UINT16, B_TRUE, B_TRUE),
270 	DMU_OTN_UINT32_ENC_DATA = DMU_OT(DMU_BSWAP_UINT32, B_FALSE, B_TRUE),
271 	DMU_OTN_UINT32_ENC_METADATA = DMU_OT(DMU_BSWAP_UINT32, B_TRUE, B_TRUE),
272 	DMU_OTN_UINT64_ENC_DATA = DMU_OT(DMU_BSWAP_UINT64, B_FALSE, B_TRUE),
273 	DMU_OTN_UINT64_ENC_METADATA = DMU_OT(DMU_BSWAP_UINT64, B_TRUE, B_TRUE),
274 	DMU_OTN_ZAP_ENC_DATA = DMU_OT(DMU_BSWAP_ZAP, B_FALSE, B_TRUE),
275 	DMU_OTN_ZAP_ENC_METADATA = DMU_OT(DMU_BSWAP_ZAP, B_TRUE, B_TRUE),
276 } dmu_object_type_t;
277 
278 /*
279  * These flags are intended to be used to specify the "txg_how"
280  * parameter when calling the dmu_tx_assign() function. See the comment
281  * above dmu_tx_assign() for more details on the meaning of these flags.
282  */
283 #define	TXG_NOWAIT	(0ULL)
284 #define	TXG_WAIT	(1ULL<<0)
285 #define	TXG_NOTHROTTLE	(1ULL<<1)
286 
287 void byteswap_uint64_array(void *buf, size_t size);
288 void byteswap_uint32_array(void *buf, size_t size);
289 void byteswap_uint16_array(void *buf, size_t size);
290 void byteswap_uint8_array(void *buf, size_t size);
291 void zap_byteswap(void *buf, size_t size);
292 void zfs_oldacl_byteswap(void *buf, size_t size);
293 void zfs_acl_byteswap(void *buf, size_t size);
294 void zfs_znode_byteswap(void *buf, size_t size);
295 
296 #define	DS_FIND_SNAPSHOTS	(1<<0)
297 #define	DS_FIND_CHILDREN	(1<<1)
298 #define	DS_FIND_SERIALIZE	(1<<2)
299 
300 /*
301  * The maximum number of bytes that can be accessed as part of one
302  * operation, including metadata.
303  */
304 #define	DMU_MAX_ACCESS (64 * 1024 * 1024) /* 64MB */
305 #define	DMU_MAX_DELETEBLKCNT (20480) /* ~5MB of indirect blocks */
306 
307 #define	DMU_USERUSED_OBJECT	(-1ULL)
308 #define	DMU_GROUPUSED_OBJECT	(-2ULL)
309 #define	DMU_PROJECTUSED_OBJECT	(-3ULL)
310 
311 /*
312  * Zap prefix for object accounting in DMU_{USER,GROUP,PROJECT}USED_OBJECT.
313  */
314 #define	DMU_OBJACCT_PREFIX	"obj-"
315 #define	DMU_OBJACCT_PREFIX_LEN	4
316 
317 /*
318  * artificial blkids for bonus buffer and spill blocks
319  */
320 #define	DMU_BONUS_BLKID		(-1ULL)
321 #define	DMU_SPILL_BLKID		(-2ULL)
322 
323 /*
324  * Public routines to create, destroy, open, and close objsets.
325  */
326 typedef void dmu_objset_create_sync_func_t(objset_t *os, void *arg,
327     cred_t *cr, dmu_tx_t *tx);
328 
329 int dmu_objset_hold(const char *name, const void *tag, objset_t **osp);
330 int dmu_objset_own(const char *name, dmu_objset_type_t type,
331     boolean_t readonly, boolean_t key_required, const void *tag,
332     objset_t **osp);
333 void dmu_objset_rele(objset_t *os, const void *tag);
334 void dmu_objset_disown(objset_t *os, boolean_t key_required, const void *tag);
335 int dmu_objset_open_ds(struct dsl_dataset *ds, objset_t **osp);
336 
337 void dmu_objset_evict_dbufs(objset_t *os);
338 int dmu_objset_create(const char *name, dmu_objset_type_t type, uint64_t flags,
339     struct dsl_crypto_params *dcp, dmu_objset_create_sync_func_t func,
340     void *arg);
341 int dmu_objset_clone(const char *name, const char *origin);
342 int dsl_destroy_snapshots_nvl(struct nvlist *snaps, boolean_t defer,
343     struct nvlist *errlist);
344 int dmu_objset_snapshot_one(const char *fsname, const char *snapname);
345 int dmu_objset_find(const char *name, int func(const char *, void *), void *arg,
346     int flags);
347 void dmu_objset_byteswap(void *buf, size_t size);
348 int dsl_dataset_rename_snapshot(const char *fsname,
349     const char *oldsnapname, const char *newsnapname, boolean_t recursive);
350 
351 typedef struct dmu_buf {
352 	uint64_t db_object;		/* object that this buffer is part of */
353 	uint64_t db_offset;		/* byte offset in this object */
354 	uint64_t db_size;		/* size of buffer in bytes */
355 	void *db_data;			/* data in buffer */
356 } dmu_buf_t;
357 
358 /*
359  * The names of zap entries in the DIRECTORY_OBJECT of the MOS.
360  */
361 #define	DMU_POOL_DIRECTORY_OBJECT	1
362 #define	DMU_POOL_CONFIG			"config"
363 #define	DMU_POOL_FEATURES_FOR_WRITE	"features_for_write"
364 #define	DMU_POOL_FEATURES_FOR_READ	"features_for_read"
365 #define	DMU_POOL_FEATURE_DESCRIPTIONS	"feature_descriptions"
366 #define	DMU_POOL_FEATURE_ENABLED_TXG	"feature_enabled_txg"
367 #define	DMU_POOL_ROOT_DATASET		"root_dataset"
368 #define	DMU_POOL_SYNC_BPOBJ		"sync_bplist"
369 #define	DMU_POOL_ERRLOG_SCRUB		"errlog_scrub"
370 #define	DMU_POOL_ERRLOG_LAST		"errlog_last"
371 #define	DMU_POOL_SPARES			"spares"
372 #define	DMU_POOL_DEFLATE		"deflate"
373 #define	DMU_POOL_HISTORY		"history"
374 #define	DMU_POOL_PROPS			"pool_props"
375 #define	DMU_POOL_L2CACHE		"l2cache"
376 #define	DMU_POOL_TMP_USERREFS		"tmp_userrefs"
377 #define	DMU_POOL_DDT			"DDT-%s-%s-%s"
378 #define	DMU_POOL_DDT_STATS		"DDT-statistics"
379 #define	DMU_POOL_CREATION_VERSION	"creation_version"
380 #define	DMU_POOL_SCAN			"scan"
381 #define	DMU_POOL_ERRORSCRUB		"error_scrub"
382 #define	DMU_POOL_FREE_BPOBJ		"free_bpobj"
383 #define	DMU_POOL_BPTREE_OBJ		"bptree_obj"
384 #define	DMU_POOL_EMPTY_BPOBJ		"empty_bpobj"
385 #define	DMU_POOL_CHECKSUM_SALT		"org.illumos:checksum_salt"
386 #define	DMU_POOL_VDEV_ZAP_MAP		"com.delphix:vdev_zap_map"
387 #define	DMU_POOL_REMOVING		"com.delphix:removing"
388 #define	DMU_POOL_OBSOLETE_BPOBJ		"com.delphix:obsolete_bpobj"
389 #define	DMU_POOL_CONDENSING_INDIRECT	"com.delphix:condensing_indirect"
390 #define	DMU_POOL_ZPOOL_CHECKPOINT	"com.delphix:zpool_checkpoint"
391 #define	DMU_POOL_LOG_SPACEMAP_ZAP	"com.delphix:log_spacemap_zap"
392 #define	DMU_POOL_DELETED_CLONES		"com.delphix:deleted_clones"
393 
394 /*
395  * Allocate an object from this objset.  The range of object numbers
396  * available is (0, DN_MAX_OBJECT).  Object 0 is the meta-dnode.
397  *
398  * The transaction must be assigned to a txg.  The newly allocated
399  * object will be "held" in the transaction (ie. you can modify the
400  * newly allocated object in this transaction).
401  *
402  * dmu_object_alloc() chooses an object and returns it in *objectp.
403  *
404  * dmu_object_claim() allocates a specific object number.  If that
405  * number is already allocated, it fails and returns EEXIST.
406  *
407  * Return 0 on success, or ENOSPC or EEXIST as specified above.
408  */
409 uint64_t dmu_object_alloc(objset_t *os, dmu_object_type_t ot,
410     int blocksize, dmu_object_type_t bonus_type, int bonus_len, dmu_tx_t *tx);
411 uint64_t dmu_object_alloc_ibs(objset_t *os, dmu_object_type_t ot, int blocksize,
412     int indirect_blockshift,
413     dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx);
414 uint64_t dmu_object_alloc_dnsize(objset_t *os, dmu_object_type_t ot,
415     int blocksize, dmu_object_type_t bonus_type, int bonus_len,
416     int dnodesize, dmu_tx_t *tx);
417 uint64_t dmu_object_alloc_hold(objset_t *os, dmu_object_type_t ot,
418     int blocksize, int indirect_blockshift, dmu_object_type_t bonustype,
419     int bonuslen, int dnodesize, dnode_t **allocated_dnode, const void *tag,
420     dmu_tx_t *tx);
421 int dmu_object_claim(objset_t *os, uint64_t object, dmu_object_type_t ot,
422     int blocksize, dmu_object_type_t bonus_type, int bonus_len, dmu_tx_t *tx);
423 int dmu_object_claim_dnsize(objset_t *os, uint64_t object, dmu_object_type_t ot,
424     int blocksize, dmu_object_type_t bonus_type, int bonus_len,
425     int dnodesize, dmu_tx_t *tx);
426 int dmu_object_reclaim(objset_t *os, uint64_t object, dmu_object_type_t ot,
427     int blocksize, dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *txp);
428 int dmu_object_reclaim_dnsize(objset_t *os, uint64_t object,
429     dmu_object_type_t ot, int blocksize, dmu_object_type_t bonustype,
430     int bonuslen, int dnodesize, boolean_t keep_spill, dmu_tx_t *tx);
431 int dmu_object_rm_spill(objset_t *os, uint64_t object, dmu_tx_t *tx);
432 
433 /*
434  * Free an object from this objset.
435  *
436  * The object's data will be freed as well (ie. you don't need to call
437  * dmu_free(object, 0, -1, tx)).
438  *
439  * The object need not be held in the transaction.
440  *
441  * If there are any holds on this object's buffers (via dmu_buf_hold()),
442  * or tx holds on the object (via dmu_tx_hold_object()), you can not
443  * free it; it fails and returns EBUSY.
444  *
445  * If the object is not allocated, it fails and returns ENOENT.
446  *
447  * Return 0 on success, or EBUSY or ENOENT as specified above.
448  */
449 int dmu_object_free(objset_t *os, uint64_t object, dmu_tx_t *tx);
450 
451 /*
452  * Find the next allocated or free object.
453  *
454  * The objectp parameter is in-out.  It will be updated to be the next
455  * object which is allocated.  Ignore objects which have not been
456  * modified since txg.
457  *
458  * XXX Can only be called on a objset with no dirty data.
459  *
460  * Returns 0 on success, or ENOENT if there are no more objects.
461  */
462 int dmu_object_next(objset_t *os, uint64_t *objectp,
463     boolean_t hole, uint64_t txg);
464 
465 /*
466  * Set the number of levels on a dnode. nlevels must be greater than the
467  * current number of levels or an EINVAL will be returned.
468  */
469 int dmu_object_set_nlevels(objset_t *os, uint64_t object, int nlevels,
470     dmu_tx_t *tx);
471 
472 /*
473  * Set the data blocksize for an object.
474  *
475  * The object cannot have any blocks allocated beyond the first.  If
476  * the first block is allocated already, the new size must be greater
477  * than the current block size.  If these conditions are not met,
478  * ENOTSUP will be returned.
479  *
480  * Returns 0 on success, or EBUSY if there are any holds on the object
481  * contents, or ENOTSUP as described above.
482  */
483 int dmu_object_set_blocksize(objset_t *os, uint64_t object, uint64_t size,
484     int ibs, dmu_tx_t *tx);
485 
486 /*
487  * Manually set the maxblkid on a dnode. This will adjust nlevels accordingly
488  * to accommodate the change. When calling this function, the caller must
489  * ensure that the object's nlevels can sufficiently support the new maxblkid.
490  */
491 int dmu_object_set_maxblkid(objset_t *os, uint64_t object, uint64_t maxblkid,
492     dmu_tx_t *tx);
493 
494 /*
495  * Set the checksum property on a dnode.  The new checksum algorithm will
496  * apply to all newly written blocks; existing blocks will not be affected.
497  */
498 void dmu_object_set_checksum(objset_t *os, uint64_t object, uint8_t checksum,
499     dmu_tx_t *tx);
500 
501 /*
502  * Set the compress property on a dnode.  The new compression algorithm will
503  * apply to all newly written blocks; existing blocks will not be affected.
504  */
505 void dmu_object_set_compress(objset_t *os, uint64_t object, uint8_t compress,
506     dmu_tx_t *tx);
507 
508 /*
509  * Get an estimated cache size for an object. Caller must expect races.
510  */
511 int dmu_object_cached_size(objset_t *os, uint64_t object,
512     uint64_t *l1sz, uint64_t *l2sz);
513 
514 void dmu_write_embedded(objset_t *os, uint64_t object, uint64_t offset,
515     void *data, uint8_t etype, uint8_t comp, int uncompressed_size,
516     int compressed_size, int byteorder, dmu_tx_t *tx);
517 void dmu_redact(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
518     dmu_tx_t *tx);
519 
520 /*
521  * Decide how to write a block: checksum, compression, number of copies, etc.
522  */
523 #define	WP_NOFILL	0x1
524 #define	WP_DMU_SYNC	0x2
525 #define	WP_SPILL	0x4
526 
527 void dmu_write_policy(objset_t *os, dnode_t *dn, int level, int wp,
528     struct zio_prop *zp);
529 
530 /*
531  * The bonus data is accessed more or less like a regular buffer.
532  * You must dmu_bonus_hold() to get the buffer, which will give you a
533  * dmu_buf_t with db_offset==-1ULL, and db_size = the size of the bonus
534  * data.  As with any normal buffer, you must call dmu_buf_will_dirty()
535  * before modifying it, and the
536  * object must be held in an assigned transaction before calling
537  * dmu_buf_will_dirty.  You may use dmu_buf_set_user() on the bonus
538  * buffer as well.  You must release what you hold with dmu_buf_rele().
539  *
540  * Returns ENOENT, EIO, or 0.
541  */
542 int dmu_bonus_hold(objset_t *os, uint64_t object, const void *tag,
543     dmu_buf_t **dbp);
544 int dmu_bonus_hold_by_dnode(dnode_t *dn, const void *tag, dmu_buf_t **dbp,
545     uint32_t flags);
546 int dmu_bonus_max(void);
547 int dmu_set_bonus(dmu_buf_t *, int, dmu_tx_t *);
548 int dmu_set_bonustype(dmu_buf_t *, dmu_object_type_t, dmu_tx_t *);
549 dmu_object_type_t dmu_get_bonustype(dmu_buf_t *);
550 int dmu_rm_spill(objset_t *, uint64_t, dmu_tx_t *);
551 
552 /*
553  * Special spill buffer support used by "SA" framework
554  */
555 
556 int dmu_spill_hold_by_bonus(dmu_buf_t *bonus, uint32_t flags, const void *tag,
557     dmu_buf_t **dbp);
558 int dmu_spill_hold_by_dnode(dnode_t *dn, uint32_t flags,
559     const void *tag, dmu_buf_t **dbp);
560 int dmu_spill_hold_existing(dmu_buf_t *bonus, const void *tag, dmu_buf_t **dbp);
561 
562 /*
563  * Obtain the DMU buffer from the specified object which contains the
564  * specified offset.  dmu_buf_hold() puts a "hold" on the buffer, so
565  * that it will remain in memory.  You must release the hold with
566  * dmu_buf_rele().  You must not access the dmu_buf_t after releasing
567  * what you hold.  You must have a hold on any dmu_buf_t* you pass to the DMU.
568  *
569  * You must call dmu_buf_read, dmu_buf_will_dirty, or dmu_buf_will_fill
570  * on the returned buffer before reading or writing the buffer's
571  * db_data.  The comments for those routines describe what particular
572  * operations are valid after calling them.
573  *
574  * The object number must be a valid, allocated object number.
575  */
576 int dmu_buf_hold(objset_t *os, uint64_t object, uint64_t offset,
577     const void *tag, dmu_buf_t **, int flags);
578 int dmu_buf_hold_array(objset_t *os, uint64_t object, uint64_t offset,
579     uint64_t length, int read, const void *tag, int *numbufsp,
580     dmu_buf_t ***dbpp);
581 int dmu_buf_hold_noread(objset_t *os, uint64_t object, uint64_t offset,
582     const void *tag, dmu_buf_t **dbp);
583 int dmu_buf_hold_by_dnode(dnode_t *dn, uint64_t offset,
584     const void *tag, dmu_buf_t **dbp, int flags);
585 int dmu_buf_hold_array_by_dnode(dnode_t *dn, uint64_t offset,
586     uint64_t length, boolean_t read, const void *tag, int *numbufsp,
587     dmu_buf_t ***dbpp, uint32_t flags);
588 int dmu_buf_hold_noread_by_dnode(dnode_t *dn, uint64_t offset, const void *tag,
589     dmu_buf_t **dbp);
590 /*
591  * Add a reference to a dmu buffer that has already been held via
592  * dmu_buf_hold() in the current context.
593  */
594 void dmu_buf_add_ref(dmu_buf_t *db, const void *tag);
595 
596 /*
597  * Attempt to add a reference to a dmu buffer that is in an unknown state,
598  * using a pointer that may have been invalidated by eviction processing.
599  * The request will succeed if the passed in dbuf still represents the
600  * same os/object/blkid, is ineligible for eviction, and has at least
601  * one hold by a user other than the syncer.
602  */
603 boolean_t dmu_buf_try_add_ref(dmu_buf_t *, objset_t *os, uint64_t object,
604     uint64_t blkid, const void *tag);
605 
606 void dmu_buf_rele(dmu_buf_t *db, const void *tag);
607 uint64_t dmu_buf_refcount(dmu_buf_t *db);
608 uint64_t dmu_buf_user_refcount(dmu_buf_t *db);
609 
610 /*
611  * dmu_buf_hold_array holds the DMU buffers which contain all bytes in a
612  * range of an object.  A pointer to an array of dmu_buf_t*'s is
613  * returned (in *dbpp).
614  *
615  * dmu_buf_rele_array releases the hold on an array of dmu_buf_t*'s, and
616  * frees the array.  The hold on the array of buffers MUST be released
617  * with dmu_buf_rele_array.  You can NOT release the hold on each buffer
618  * individually with dmu_buf_rele.
619  */
620 int dmu_buf_hold_array_by_bonus(dmu_buf_t *db, uint64_t offset,
621     uint64_t length, boolean_t read, const void *tag,
622     int *numbufsp, dmu_buf_t ***dbpp);
623 void dmu_buf_rele_array(dmu_buf_t **, int numbufs, const void *tag);
624 
625 typedef void dmu_buf_evict_func_t(void *user_ptr);
626 
627 /*
628  * A DMU buffer user object may be associated with a dbuf for the
629  * duration of its lifetime.  This allows the user of a dbuf (client)
630  * to attach private data to a dbuf (e.g. in-core only data such as a
631  * dnode_children_t, zap_t, or zap_leaf_t) and be optionally notified
632  * when that dbuf has been evicted.  Clients typically respond to the
633  * eviction notification by freeing their private data, thus ensuring
634  * the same lifetime for both dbuf and private data.
635  *
636  * The mapping from a dmu_buf_user_t to any client private data is the
637  * client's responsibility.  All current consumers of the API with private
638  * data embed a dmu_buf_user_t as the first member of the structure for
639  * their private data.  This allows conversions between the two types
640  * with a simple cast.  Since the DMU buf user API never needs access
641  * to the private data, other strategies can be employed if necessary
642  * or convenient for the client (e.g. using container_of() to do the
643  * conversion for private data that cannot have the dmu_buf_user_t as
644  * its first member).
645  *
646  * Eviction callbacks are executed without the dbuf mutex held or any
647  * other type of mechanism to guarantee that the dbuf is still available.
648  * For this reason, users must assume the dbuf has already been freed
649  * and not reference the dbuf from the callback context.
650  *
651  * Users requesting "immediate eviction" are notified as soon as the dbuf
652  * is only referenced by dirty records (dirties == holds).  Otherwise the
653  * notification occurs after eviction processing for the dbuf begins.
654  */
655 typedef struct dmu_buf_user {
656 	/*
657 	 * Asynchronous user eviction callback state.
658 	 */
659 	taskq_ent_t	dbu_tqent;
660 
661 	/* Size of user data, for inclusion in dbuf_cache accounting. */
662 	uint64_t	dbu_size;
663 
664 	/*
665 	 * This instance's eviction function pointers.
666 	 *
667 	 * dbu_evict_func_sync is called synchronously and then
668 	 * dbu_evict_func_async is executed asynchronously on a taskq.
669 	 */
670 	dmu_buf_evict_func_t *dbu_evict_func_sync;
671 	dmu_buf_evict_func_t *dbu_evict_func_async;
672 #ifdef ZFS_DEBUG
673 	/*
674 	 * Pointer to user's dbuf pointer.  NULL for clients that do
675 	 * not associate a dbuf with their user data.
676 	 *
677 	 * The dbuf pointer is cleared upon eviction so as to catch
678 	 * use-after-evict bugs in clients.
679 	 */
680 	dmu_buf_t **dbu_clear_on_evict_dbufp;
681 #endif
682 } dmu_buf_user_t;
683 
684 /*
685  * Initialize the given dmu_buf_user_t instance with the eviction function
686  * evict_func, to be called when the user is evicted.
687  *
688  * NOTE: This function should only be called once on a given dmu_buf_user_t.
689  *       To allow enforcement of this, dbu must already be zeroed on entry.
690  */
691 static inline void
692 dmu_buf_init_user(dmu_buf_user_t *dbu, dmu_buf_evict_func_t *evict_func_sync,
693     dmu_buf_evict_func_t *evict_func_async,
694     dmu_buf_t **clear_on_evict_dbufp __maybe_unused)
695 {
696 	ASSERT(dbu->dbu_evict_func_sync == NULL);
697 	ASSERT(dbu->dbu_evict_func_async == NULL);
698 
699 	/* must have at least one evict func */
700 	IMPLY(evict_func_sync == NULL, evict_func_async != NULL);
701 	dbu->dbu_evict_func_sync = evict_func_sync;
702 	dbu->dbu_evict_func_async = evict_func_async;
703 	taskq_init_ent(&dbu->dbu_tqent);
704 #ifdef ZFS_DEBUG
705 	dbu->dbu_clear_on_evict_dbufp = clear_on_evict_dbufp;
706 #endif
707 }
708 
709 /*
710  * Attach user data to a dbuf and mark it for normal (when the dbuf's
711  * data is cleared or its reference count goes to zero) eviction processing.
712  *
713  * Returns NULL on success, or the existing user if another user currently
714  * owns the buffer.
715  */
716 void *dmu_buf_set_user(dmu_buf_t *db, dmu_buf_user_t *user);
717 
718 /*
719  * Attach user data to a dbuf and mark it for immediate (its dirty and
720  * reference counts are equal) eviction processing.
721  *
722  * Returns NULL on success, or the existing user if another user currently
723  * owns the buffer.
724  */
725 void *dmu_buf_set_user_ie(dmu_buf_t *db, dmu_buf_user_t *user);
726 
727 /*
728  * Replace the current user of a dbuf.
729  *
730  * If given the current user of a dbuf, replaces the dbuf's user with
731  * "new_user" and returns the user data pointer that was replaced.
732  * Otherwise returns the current, and unmodified, dbuf user pointer.
733  */
734 void *dmu_buf_replace_user(dmu_buf_t *db,
735     dmu_buf_user_t *old_user, dmu_buf_user_t *new_user);
736 
737 /*
738  * Remove the specified user data for a DMU buffer.
739  *
740  * Returns the user that was removed on success, or the current user if
741  * another user currently owns the buffer.
742  */
743 void *dmu_buf_remove_user(dmu_buf_t *db, dmu_buf_user_t *user);
744 
745 /*
746  * User data size accounting. This can be used to artifically inflate the size
747  * of the dbuf during cache accounting, so that dbuf_evict_thread evicts enough
748  * to satisfy memory reclaim requests. It's not used for anything else, and
749  * defaults to 0.
750  */
751 uint64_t dmu_buf_user_size(dmu_buf_t *db);
752 void dmu_buf_add_user_size(dmu_buf_t *db, uint64_t nadd);
753 void dmu_buf_sub_user_size(dmu_buf_t *db, uint64_t nsub);
754 
755 /*
756  * Returns the user data (dmu_buf_user_t *) associated with this dbuf.
757  */
758 void *dmu_buf_get_user(dmu_buf_t *db);
759 
760 objset_t *dmu_buf_get_objset(dmu_buf_t *db);
761 
762 /* Block until any in-progress dmu buf user evictions complete. */
763 void dmu_buf_user_evict_wait(void);
764 
765 /*
766  * Returns the blkptr associated with this dbuf, or NULL if not set.
767  */
768 struct blkptr *dmu_buf_get_blkptr(dmu_buf_t *db);
769 
770 /*
771  * Indicate that you are going to modify the buffer's data (db_data).
772  *
773  * The transaction (tx) must be assigned to a txg (ie. you've called
774  * dmu_tx_assign()).  The buffer's object must be held in the tx
775  * (ie. you've called dmu_tx_hold_object(tx, db->db_object)).
776  */
777 void dmu_buf_will_dirty(dmu_buf_t *db, dmu_tx_t *tx);
778 boolean_t dmu_buf_is_dirty(dmu_buf_t *db, dmu_tx_t *tx);
779 void dmu_buf_set_crypt_params(dmu_buf_t *db_fake, boolean_t byteorder,
780     const uint8_t *salt, const uint8_t *iv, const uint8_t *mac, dmu_tx_t *tx);
781 
782 /*
783  * You must create a transaction, then hold the objects which you will
784  * (or might) modify as part of this transaction.  Then you must assign
785  * the transaction to a transaction group.  Once the transaction has
786  * been assigned, you can modify buffers which belong to held objects as
787  * part of this transaction.  You can't modify buffers before the
788  * transaction has been assigned; you can't modify buffers which don't
789  * belong to objects which this transaction holds; you can't hold
790  * objects once the transaction has been assigned.  You may hold an
791  * object which you are going to free (with dmu_object_free()), but you
792  * don't have to.
793  *
794  * You can abort the transaction before it has been assigned.
795  *
796  * Note that you may hold buffers (with dmu_buf_hold) at any time,
797  * regardless of transaction state.
798  */
799 
800 #define	DMU_NEW_OBJECT	(-1ULL)
801 #define	DMU_OBJECT_END	(-1ULL)
802 
803 dmu_tx_t *dmu_tx_create(objset_t *os);
804 void dmu_tx_hold_write(dmu_tx_t *tx, uint64_t object, uint64_t off, int len);
805 void dmu_tx_hold_write_by_dnode(dmu_tx_t *tx, dnode_t *dn, uint64_t off,
806     int len);
807 void dmu_tx_hold_append(dmu_tx_t *tx, uint64_t object, uint64_t off, int len);
808 void dmu_tx_hold_append_by_dnode(dmu_tx_t *tx, dnode_t *dn, uint64_t off,
809     int len);
810 void dmu_tx_hold_clone_by_dnode(dmu_tx_t *tx, dnode_t *dn, uint64_t off,
811     int len);
812 void dmu_tx_hold_free(dmu_tx_t *tx, uint64_t object, uint64_t off,
813     uint64_t len);
814 void dmu_tx_hold_free_by_dnode(dmu_tx_t *tx, dnode_t *dn, uint64_t off,
815     uint64_t len);
816 void dmu_tx_hold_zap(dmu_tx_t *tx, uint64_t object, int add, const char *name);
817 void dmu_tx_hold_zap_by_dnode(dmu_tx_t *tx, dnode_t *dn, int add,
818     const char *name);
819 void dmu_tx_hold_bonus(dmu_tx_t *tx, uint64_t object);
820 void dmu_tx_hold_bonus_by_dnode(dmu_tx_t *tx, dnode_t *dn);
821 void dmu_tx_hold_spill(dmu_tx_t *tx, uint64_t object);
822 void dmu_tx_hold_sa(dmu_tx_t *tx, struct sa_handle *hdl, boolean_t may_grow);
823 void dmu_tx_hold_sa_create(dmu_tx_t *tx, int total_size);
824 void dmu_tx_abort(dmu_tx_t *tx);
825 int dmu_tx_assign(dmu_tx_t *tx, uint64_t txg_how);
826 void dmu_tx_wait(dmu_tx_t *tx);
827 void dmu_tx_commit(dmu_tx_t *tx);
828 void dmu_tx_mark_netfree(dmu_tx_t *tx);
829 
830 /*
831  * To register a commit callback, dmu_tx_callback_register() must be called.
832  *
833  * dcb_data is a pointer to caller private data that is passed on as a
834  * callback parameter. The caller is responsible for properly allocating and
835  * freeing it.
836  *
837  * When registering a callback, the transaction must be already created, but
838  * it cannot be committed or aborted. It can be assigned to a txg or not.
839  *
840  * The callback will be called after the transaction has been safely written
841  * to stable storage and will also be called if the dmu_tx is aborted.
842  * If there is any error which prevents the transaction from being committed to
843  * disk, the callback will be called with a value of error != 0.
844  *
845  * When multiple callbacks are registered to the transaction, the callbacks
846  * will be called in reverse order to let Lustre, the only user of commit
847  * callback currently, take the fast path of its commit callback handling.
848  */
849 typedef void dmu_tx_callback_func_t(void *dcb_data, int error);
850 
851 void dmu_tx_callback_register(dmu_tx_t *tx, dmu_tx_callback_func_t *dcb_func,
852     void *dcb_data);
853 void dmu_tx_do_callbacks(list_t *cb_list, int error);
854 
855 /*
856  * Free up the data blocks for a defined range of a file.  If size is
857  * -1, the range from offset to end-of-file is freed.
858  */
859 int dmu_free_range(objset_t *os, uint64_t object, uint64_t offset,
860     uint64_t size, dmu_tx_t *tx);
861 int dmu_free_long_range(objset_t *os, uint64_t object, uint64_t offset,
862     uint64_t size);
863 int dmu_free_long_object(objset_t *os, uint64_t object);
864 
865 /*
866  * Convenience functions.
867  *
868  * Canfail routines will return 0 on success, or an errno if there is a
869  * nonrecoverable I/O error.
870  */
871 #define	DMU_READ_PREFETCH	0 /* prefetch */
872 #define	DMU_READ_NO_PREFETCH	1 /* don't prefetch */
873 #define	DMU_READ_NO_DECRYPT	2 /* don't decrypt */
874 int dmu_read(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
875 	void *buf, uint32_t flags);
876 int dmu_read_by_dnode(dnode_t *dn, uint64_t offset, uint64_t size, void *buf,
877     uint32_t flags);
878 void dmu_write(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
879 	const void *buf, dmu_tx_t *tx);
880 void dmu_write_by_dnode(dnode_t *dn, uint64_t offset, uint64_t size,
881     const void *buf, dmu_tx_t *tx);
882 void dmu_prealloc(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
883 	dmu_tx_t *tx);
884 #ifdef _KERNEL
885 int dmu_read_uio(objset_t *os, uint64_t object, zfs_uio_t *uio, uint64_t size);
886 int dmu_read_uio_dbuf(dmu_buf_t *zdb, zfs_uio_t *uio, uint64_t size);
887 int dmu_read_uio_dnode(dnode_t *dn, zfs_uio_t *uio, uint64_t size);
888 int dmu_write_uio(objset_t *os, uint64_t object, zfs_uio_t *uio, uint64_t size,
889 	dmu_tx_t *tx);
890 int dmu_write_uio_dbuf(dmu_buf_t *zdb, zfs_uio_t *uio, uint64_t size,
891 	dmu_tx_t *tx);
892 int dmu_write_uio_dnode(dnode_t *dn, zfs_uio_t *uio, uint64_t size,
893 	dmu_tx_t *tx);
894 #endif
895 struct arc_buf *dmu_request_arcbuf(dmu_buf_t *handle, int size);
896 void dmu_return_arcbuf(struct arc_buf *buf);
897 int dmu_assign_arcbuf_by_dnode(dnode_t *dn, uint64_t offset,
898     struct arc_buf *buf, dmu_tx_t *tx);
899 int dmu_assign_arcbuf_by_dbuf(dmu_buf_t *handle, uint64_t offset,
900     struct arc_buf *buf, dmu_tx_t *tx);
901 #define	dmu_assign_arcbuf	dmu_assign_arcbuf_by_dbuf
902 extern uint_t zfs_max_recordsize;
903 
904 /*
905  * Asynchronously try to read in the data.
906  */
907 void dmu_prefetch(objset_t *os, uint64_t object, int64_t level, uint64_t offset,
908 	uint64_t len, enum zio_priority pri);
909 void dmu_prefetch_by_dnode(dnode_t *dn, int64_t level, uint64_t offset,
910 	uint64_t len, enum zio_priority pri);
911 void dmu_prefetch_dnode(objset_t *os, uint64_t object, enum zio_priority pri);
912 int dmu_prefetch_wait(objset_t *os, uint64_t object, uint64_t offset,
913     uint64_t size);
914 
915 typedef struct dmu_object_info {
916 	/* All sizes are in bytes unless otherwise indicated. */
917 	uint32_t doi_data_block_size;
918 	uint32_t doi_metadata_block_size;
919 	dmu_object_type_t doi_type;
920 	dmu_object_type_t doi_bonus_type;
921 	uint64_t doi_bonus_size;
922 	uint8_t doi_indirection;		/* 2 = dnode->indirect->data */
923 	uint8_t doi_checksum;
924 	uint8_t doi_compress;
925 	uint8_t doi_nblkptr;
926 	uint8_t doi_pad[4];
927 	uint64_t doi_dnodesize;
928 	uint64_t doi_physical_blocks_512;	/* data + metadata, 512b blks */
929 	uint64_t doi_max_offset;
930 	uint64_t doi_fill_count;		/* number of non-empty blocks */
931 } dmu_object_info_t;
932 
933 typedef void (*const arc_byteswap_func_t)(void *buf, size_t size);
934 
935 typedef struct dmu_object_type_info {
936 	dmu_object_byteswap_t	ot_byteswap;
937 	boolean_t		ot_metadata;
938 	boolean_t		ot_dbuf_metadata_cache;
939 	boolean_t		ot_encrypt;
940 	const char		*ot_name;
941 } dmu_object_type_info_t;
942 
943 typedef const struct dmu_object_byteswap_info {
944 	arc_byteswap_func_t	 ob_func;
945 	const char		*ob_name;
946 } dmu_object_byteswap_info_t;
947 
948 extern const dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES];
949 extern dmu_object_byteswap_info_t dmu_ot_byteswap[DMU_BSWAP_NUMFUNCS];
950 
951 /*
952  * Get information on a DMU object.
953  *
954  * Return 0 on success or ENOENT if object is not allocated.
955  *
956  * If doi is NULL, just indicates whether the object exists.
957  */
958 int dmu_object_info(objset_t *os, uint64_t object, dmu_object_info_t *doi);
959 void __dmu_object_info_from_dnode(struct dnode *dn, dmu_object_info_t *doi);
960 /* Like dmu_object_info, but faster if you have a held dnode in hand. */
961 void dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi);
962 /* Like dmu_object_info, but faster if you have a held dbuf in hand. */
963 void dmu_object_info_from_db(dmu_buf_t *db, dmu_object_info_t *doi);
964 /*
965  * Like dmu_object_info_from_db, but faster still when you only care about
966  * the size.
967  */
968 void dmu_object_size_from_db(dmu_buf_t *db, uint32_t *blksize,
969     u_longlong_t *nblk512);
970 
971 void dmu_object_dnsize_from_db(dmu_buf_t *db, int *dnsize);
972 
973 typedef struct dmu_objset_stats {
974 	uint64_t dds_num_clones; /* number of clones of this */
975 	uint64_t dds_creation_txg;
976 	uint64_t dds_guid;
977 	dmu_objset_type_t dds_type;
978 	uint8_t dds_is_snapshot;
979 	uint8_t dds_inconsistent;
980 	uint8_t dds_redacted;
981 	char dds_origin[ZFS_MAX_DATASET_NAME_LEN];
982 } dmu_objset_stats_t;
983 
984 /*
985  * Get stats on a dataset.
986  */
987 void dmu_objset_fast_stat(objset_t *os, dmu_objset_stats_t *stat);
988 
989 /*
990  * Add entries to the nvlist for all the objset's properties.  See
991  * zfs_prop_table[] and zfs(1m) for details on the properties.
992  */
993 void dmu_objset_stats(objset_t *os, struct nvlist *nv);
994 
995 /*
996  * Get the space usage statistics for statvfs().
997  *
998  * refdbytes is the amount of space "referenced" by this objset.
999  * availbytes is the amount of space available to this objset, taking
1000  * into account quotas & reservations, assuming that no other objsets
1001  * use the space first.  These values correspond to the 'referenced' and
1002  * 'available' properties, described in the zfs(1m) manpage.
1003  *
1004  * usedobjs and availobjs are the number of objects currently allocated,
1005  * and available.
1006  */
1007 void dmu_objset_space(objset_t *os, uint64_t *refdbytesp, uint64_t *availbytesp,
1008     uint64_t *usedobjsp, uint64_t *availobjsp);
1009 
1010 /*
1011  * The fsid_guid is a 56-bit ID that can change to avoid collisions.
1012  * (Contrast with the ds_guid which is a 64-bit ID that will never
1013  * change, so there is a small probability that it will collide.)
1014  */
1015 uint64_t dmu_objset_fsid_guid(objset_t *os);
1016 
1017 /*
1018  * Get the [cm]time for an objset's snapshot dir
1019  */
1020 inode_timespec_t dmu_objset_snap_cmtime(objset_t *os);
1021 
1022 int dmu_objset_is_snapshot(objset_t *os);
1023 
1024 extern struct spa *dmu_objset_spa(objset_t *os);
1025 extern struct zilog *dmu_objset_zil(objset_t *os);
1026 extern struct dsl_pool *dmu_objset_pool(objset_t *os);
1027 extern struct dsl_dataset *dmu_objset_ds(objset_t *os);
1028 extern void dmu_objset_name(objset_t *os, char *buf);
1029 extern dmu_objset_type_t dmu_objset_type(objset_t *os);
1030 extern uint64_t dmu_objset_id(objset_t *os);
1031 extern uint64_t dmu_objset_dnodesize(objset_t *os);
1032 extern zfs_sync_type_t dmu_objset_syncprop(objset_t *os);
1033 extern zfs_logbias_op_t dmu_objset_logbias(objset_t *os);
1034 extern int dmu_objset_blksize(objset_t *os);
1035 extern int dmu_snapshot_list_next(objset_t *os, int namelen, char *name,
1036     uint64_t *id, uint64_t *offp, boolean_t *case_conflict);
1037 extern int dmu_snapshot_lookup(objset_t *os, const char *name, uint64_t *val);
1038 extern int dmu_snapshot_realname(objset_t *os, const char *name, char *real,
1039     int maxlen, boolean_t *conflict);
1040 extern int dmu_dir_list_next(objset_t *os, int namelen, char *name,
1041     uint64_t *idp, uint64_t *offp);
1042 
1043 typedef struct zfs_file_info {
1044 	uint64_t zfi_user;
1045 	uint64_t zfi_group;
1046 	uint64_t zfi_project;
1047 	uint64_t zfi_generation;
1048 } zfs_file_info_t;
1049 
1050 typedef int file_info_cb_t(dmu_object_type_t bonustype, const void *data,
1051     struct zfs_file_info *zoi);
1052 extern void dmu_objset_register_type(dmu_objset_type_t ost,
1053     file_info_cb_t *cb);
1054 extern void dmu_objset_set_user(objset_t *os, void *user_ptr);
1055 extern void *dmu_objset_get_user(objset_t *os);
1056 
1057 /*
1058  * Return the txg number for the given assigned transaction.
1059  */
1060 uint64_t dmu_tx_get_txg(dmu_tx_t *tx);
1061 
1062 /*
1063  * Synchronous write.
1064  * If a parent zio is provided this function initiates a write on the
1065  * provided buffer as a child of the parent zio.
1066  * In the absence of a parent zio, the write is completed synchronously.
1067  * At write completion, blk is filled with the bp of the written block.
1068  * Note that while the data covered by this function will be on stable
1069  * storage when the write completes this new data does not become a
1070  * permanent part of the file until the associated transaction commits.
1071  */
1072 
1073 /*
1074  * {zfs,zvol,ztest}_get_done() args
1075  */
1076 typedef struct zgd {
1077 	struct lwb	*zgd_lwb;
1078 	struct blkptr	*zgd_bp;
1079 	dmu_buf_t	*zgd_db;
1080 	struct zfs_locked_range *zgd_lr;
1081 	void		*zgd_private;
1082 } zgd_t;
1083 
1084 typedef void dmu_sync_cb_t(zgd_t *arg, int error);
1085 int dmu_sync(struct zio *zio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd);
1086 
1087 /*
1088  * Find the next hole or data block in file starting at *off
1089  * Return found offset in *off. Return ESRCH for end of file.
1090  */
1091 int dmu_offset_next(objset_t *os, uint64_t object, boolean_t hole,
1092     uint64_t *off);
1093 
1094 int dmu_read_l0_bps(objset_t *os, uint64_t object, uint64_t offset,
1095     uint64_t length, struct blkptr *bps, size_t *nbpsp);
1096 int dmu_brt_clone(objset_t *os, uint64_t object, uint64_t offset,
1097     uint64_t length, dmu_tx_t *tx, const struct blkptr *bps, size_t nbps);
1098 
1099 /*
1100  * Initial setup and final teardown.
1101  */
1102 extern void dmu_init(void);
1103 extern void dmu_fini(void);
1104 
1105 typedef void (*dmu_traverse_cb_t)(objset_t *os, void *arg, struct blkptr *bp,
1106     uint64_t object, uint64_t offset, int len);
1107 void dmu_traverse_objset(objset_t *os, uint64_t txg_start,
1108     dmu_traverse_cb_t cb, void *arg);
1109 
1110 int dmu_diff(const char *tosnap_name, const char *fromsnap_name,
1111     zfs_file_t *fp, offset_t *offp);
1112 
1113 /* CRC64 table */
1114 #define	ZFS_CRC64_POLY	0xC96C5795D7870F42ULL	/* ECMA-182, reflected form */
1115 extern uint64_t zfs_crc64_table[256];
1116 
1117 extern uint_t dmu_prefetch_max;
1118 
1119 #ifdef	__cplusplus
1120 }
1121 #endif
1122 
1123 #endif	/* _SYS_DMU_H */
1124