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 http://www.opensolaris.org/os/licensing.
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 /*
23 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
24 * Copyright (c) 2013 by Delphix. All rights reserved.
25 * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
26 * Copyright (c) 2012, Joyent, Inc. All rights reserved.
27 */
28
29 /* Portions Copyright 2010 Robert Milkowski */
30
31 #ifndef _SYS_DMU_H
32 #define _SYS_DMU_H
33
34 /*
35 * This file describes the interface that the DMU provides for its
36 * consumers.
37 *
38 * The DMU also interacts with the SPA. That interface is described in
39 * dmu_spa.h.
40 */
41
42 #include <sys/inttypes.h>
43 #include <sys/types.h>
44 #include <sys/param.h>
45 #include <sys/cred.h>
46 #include <sys/time.h>
47 #include <sys/fs/zfs.h>
48
49 #ifdef __cplusplus
50 extern "C" {
51 #endif
52
53 struct uio;
54 struct xuio;
55 struct page;
56 struct vnode;
57 struct spa;
58 struct zilog;
59 struct zio;
60 struct blkptr;
61 struct zap_cursor;
62 struct dsl_dataset;
63 struct dsl_pool;
64 struct dnode;
65 struct drr_begin;
66 struct drr_end;
67 struct zbookmark;
68 struct spa;
69 struct nvlist;
70 struct arc_buf;
71 struct zio_prop;
72 struct sa_handle;
73
74 typedef struct objset objset_t;
75 typedef struct dmu_tx dmu_tx_t;
76 typedef struct dsl_dir dsl_dir_t;
77
78 typedef enum dmu_object_byteswap {
79 DMU_BSWAP_UINT8,
80 DMU_BSWAP_UINT16,
81 DMU_BSWAP_UINT32,
82 DMU_BSWAP_UINT64,
83 DMU_BSWAP_ZAP,
84 DMU_BSWAP_DNODE,
85 DMU_BSWAP_OBJSET,
86 DMU_BSWAP_ZNODE,
87 DMU_BSWAP_OLDACL,
88 DMU_BSWAP_ACL,
89 /*
90 * Allocating a new byteswap type number makes the on-disk format
91 * incompatible with any other format that uses the same number.
92 *
93 * Data can usually be structured to work with one of the
94 * DMU_BSWAP_UINT* or DMU_BSWAP_ZAP types.
95 */
96 DMU_BSWAP_NUMFUNCS
97 } dmu_object_byteswap_t;
98
99 #define DMU_OT_NEWTYPE 0x80
100 #define DMU_OT_METADATA 0x40
101 #define DMU_OT_BYTESWAP_MASK 0x3f
102
103 /*
104 * Defines a uint8_t object type. Object types specify if the data
105 * in the object is metadata (boolean) and how to byteswap the data
106 * (dmu_object_byteswap_t).
107 */
108 #define DMU_OT(byteswap, metadata) \
109 (DMU_OT_NEWTYPE | \
110 ((metadata) ? DMU_OT_METADATA : 0) | \
111 ((byteswap) & DMU_OT_BYTESWAP_MASK))
112
113 #define DMU_OT_IS_VALID(ot) (((ot) & DMU_OT_NEWTYPE) ? \
114 ((ot) & DMU_OT_BYTESWAP_MASK) < DMU_BSWAP_NUMFUNCS : \
115 (ot) < DMU_OT_NUMTYPES)
116
117 #define DMU_OT_IS_METADATA(ot) (((ot) & DMU_OT_NEWTYPE) ? \
118 ((ot) & DMU_OT_METADATA) : \
119 dmu_ot[(ot)].ot_metadata)
120
121 #define DMU_OT_BYTESWAP(ot) (((ot) & DMU_OT_NEWTYPE) ? \
122 ((ot) & DMU_OT_BYTESWAP_MASK) : \
123 dmu_ot[(ot)].ot_byteswap)
124
125 typedef enum dmu_object_type {
126 DMU_OT_NONE,
127 /* general: */
128 DMU_OT_OBJECT_DIRECTORY, /* ZAP */
129 DMU_OT_OBJECT_ARRAY, /* UINT64 */
130 DMU_OT_PACKED_NVLIST, /* UINT8 (XDR by nvlist_pack/unpack) */
131 DMU_OT_PACKED_NVLIST_SIZE, /* UINT64 */
132 DMU_OT_BPOBJ, /* UINT64 */
133 DMU_OT_BPOBJ_HDR, /* UINT64 */
134 /* spa: */
135 DMU_OT_SPACE_MAP_HEADER, /* UINT64 */
136 DMU_OT_SPACE_MAP, /* UINT64 */
137 /* zil: */
138 DMU_OT_INTENT_LOG, /* UINT64 */
139 /* dmu: */
140 DMU_OT_DNODE, /* DNODE */
141 DMU_OT_OBJSET, /* OBJSET */
142 /* dsl: */
143 DMU_OT_DSL_DIR, /* UINT64 */
144 DMU_OT_DSL_DIR_CHILD_MAP, /* ZAP */
145 DMU_OT_DSL_DS_SNAP_MAP, /* ZAP */
146 DMU_OT_DSL_PROPS, /* ZAP */
147 DMU_OT_DSL_DATASET, /* UINT64 */
148 /* zpl: */
149 DMU_OT_ZNODE, /* ZNODE */
150 DMU_OT_OLDACL, /* Old ACL */
151 DMU_OT_PLAIN_FILE_CONTENTS, /* UINT8 */
152 DMU_OT_DIRECTORY_CONTENTS, /* ZAP */
153 DMU_OT_MASTER_NODE, /* ZAP */
154 DMU_OT_UNLINKED_SET, /* ZAP */
155 /* zvol: */
156 DMU_OT_ZVOL, /* UINT8 */
157 DMU_OT_ZVOL_PROP, /* ZAP */
158 /* other; for testing only! */
159 DMU_OT_PLAIN_OTHER, /* UINT8 */
160 DMU_OT_UINT64_OTHER, /* UINT64 */
161 DMU_OT_ZAP_OTHER, /* ZAP */
162 /* new object types: */
163 DMU_OT_ERROR_LOG, /* ZAP */
164 DMU_OT_SPA_HISTORY, /* UINT8 */
165 DMU_OT_SPA_HISTORY_OFFSETS, /* spa_his_phys_t */
166 DMU_OT_POOL_PROPS, /* ZAP */
167 DMU_OT_DSL_PERMS, /* ZAP */
168 DMU_OT_ACL, /* ACL */
169 DMU_OT_SYSACL, /* SYSACL */
170 DMU_OT_FUID, /* FUID table (Packed NVLIST UINT8) */
171 DMU_OT_FUID_SIZE, /* FUID table size UINT64 */
172 DMU_OT_NEXT_CLONES, /* ZAP */
173 DMU_OT_SCAN_QUEUE, /* ZAP */
174 DMU_OT_USERGROUP_USED, /* ZAP */
175 DMU_OT_USERGROUP_QUOTA, /* ZAP */
176 DMU_OT_USERREFS, /* ZAP */
177 DMU_OT_DDT_ZAP, /* ZAP */
178 DMU_OT_DDT_STATS, /* ZAP */
179 DMU_OT_SA, /* System attr */
180 DMU_OT_SA_MASTER_NODE, /* ZAP */
181 DMU_OT_SA_ATTR_REGISTRATION, /* ZAP */
182 DMU_OT_SA_ATTR_LAYOUTS, /* ZAP */
183 DMU_OT_SCAN_XLATE, /* ZAP */
184 DMU_OT_DEDUP, /* fake dedup BP from ddt_bp_create() */
185 DMU_OT_DEADLIST, /* ZAP */
186 DMU_OT_DEADLIST_HDR, /* UINT64 */
187 DMU_OT_DSL_CLONES, /* ZAP */
188 DMU_OT_BPOBJ_SUBOBJ, /* UINT64 */
189 /*
190 * Do not allocate new object types here. Doing so makes the on-disk
191 * format incompatible with any other format that uses the same object
192 * type number.
193 *
194 * When creating an object which does not have one of the above types
195 * use the DMU_OTN_* type with the correct byteswap and metadata
196 * values.
197 *
198 * The DMU_OTN_* types do not have entries in the dmu_ot table,
199 * use the DMU_OT_IS_METDATA() and DMU_OT_BYTESWAP() macros instead
200 * of indexing into dmu_ot directly (this works for both DMU_OT_* types
201 * and DMU_OTN_* types).
202 */
203 DMU_OT_NUMTYPES,
204
205 /*
206 * Names for valid types declared with DMU_OT().
207 */
208 DMU_OTN_UINT8_DATA = DMU_OT(DMU_BSWAP_UINT8, B_FALSE),
209 DMU_OTN_UINT8_METADATA = DMU_OT(DMU_BSWAP_UINT8, B_TRUE),
210 DMU_OTN_UINT16_DATA = DMU_OT(DMU_BSWAP_UINT16, B_FALSE),
211 DMU_OTN_UINT16_METADATA = DMU_OT(DMU_BSWAP_UINT16, B_TRUE),
212 DMU_OTN_UINT32_DATA = DMU_OT(DMU_BSWAP_UINT32, B_FALSE),
213 DMU_OTN_UINT32_METADATA = DMU_OT(DMU_BSWAP_UINT32, B_TRUE),
214 DMU_OTN_UINT64_DATA = DMU_OT(DMU_BSWAP_UINT64, B_FALSE),
215 DMU_OTN_UINT64_METADATA = DMU_OT(DMU_BSWAP_UINT64, B_TRUE),
216 DMU_OTN_ZAP_DATA = DMU_OT(DMU_BSWAP_ZAP, B_FALSE),
217 DMU_OTN_ZAP_METADATA = DMU_OT(DMU_BSWAP_ZAP, B_TRUE),
218 } dmu_object_type_t;
219
220 typedef enum txg_how {
221 TXG_WAIT = 1,
222 TXG_NOWAIT,
223 TXG_WAITED,
224 } txg_how_t;
225
226 void byteswap_uint64_array(void *buf, size_t size);
227 void byteswap_uint32_array(void *buf, size_t size);
228 void byteswap_uint16_array(void *buf, size_t size);
229 void byteswap_uint8_array(void *buf, size_t size);
230 void zap_byteswap(void *buf, size_t size);
231 void zfs_oldacl_byteswap(void *buf, size_t size);
232 void zfs_acl_byteswap(void *buf, size_t size);
233 void zfs_znode_byteswap(void *buf, size_t size);
234
235 #define DS_FIND_SNAPSHOTS (1<<0)
236 #define DS_FIND_CHILDREN (1<<1)
237
238 /*
239 * The maximum number of bytes that can be accessed as part of one
240 * operation, including metadata.
241 */
242 #define DMU_MAX_ACCESS (10<<20) /* 10MB */
243 #define DMU_MAX_DELETEBLKCNT (20480) /* ~5MB of indirect blocks */
244
245 #define DMU_USERUSED_OBJECT (-1ULL)
246 #define DMU_GROUPUSED_OBJECT (-2ULL)
247 #define DMU_DEADLIST_OBJECT (-3ULL)
248
249 /*
250 * artificial blkids for bonus buffer and spill blocks
251 */
252 #define DMU_BONUS_BLKID (-1ULL)
253 #define DMU_SPILL_BLKID (-2ULL)
254 /*
255 * Public routines to create, destroy, open, and close objsets.
256 */
257 int dmu_objset_hold(const char *name, void *tag, objset_t **osp);
258 int dmu_objset_own(const char *name, dmu_objset_type_t type,
259 boolean_t readonly, void *tag, objset_t **osp);
260 void dmu_objset_rele(objset_t *os, void *tag);
261 void dmu_objset_disown(objset_t *os, void *tag);
262 int dmu_objset_open_ds(struct dsl_dataset *ds, objset_t **osp);
263
264 void dmu_objset_evict_dbufs(objset_t *os);
265 int dmu_objset_create(const char *name, dmu_objset_type_t type, uint64_t flags,
266 void (*func)(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx), void *arg);
267 int dmu_objset_clone(const char *name, const char *origin);
268 int dsl_destroy_snapshots_nvl(struct nvlist *snaps, boolean_t defer,
269 struct nvlist *errlist);
270 int dmu_objset_snapshot_one(const char *fsname, const char *snapname);
271 int dmu_objset_snapshot_tmp(const char *, const char *, int);
272 int dmu_objset_find(char *name, int func(const char *, void *), void *arg,
273 int flags);
274 void dmu_objset_byteswap(void *buf, size_t size);
275 int dsl_dataset_rename_snapshot(const char *fsname,
276 const char *oldsnapname, const char *newsnapname, boolean_t recursive);
277
278 typedef struct dmu_buf {
279 uint64_t db_object; /* object that this buffer is part of */
280 uint64_t db_offset; /* byte offset in this object */
281 uint64_t db_size; /* size of buffer in bytes */
282 void *db_data; /* data in buffer */
283 } dmu_buf_t;
284
285 typedef void dmu_buf_evict_func_t(struct dmu_buf *db, void *user_ptr);
286
287 /*
288 * The names of zap entries in the DIRECTORY_OBJECT of the MOS.
289 */
290 #define DMU_POOL_DIRECTORY_OBJECT 1
291 #define DMU_POOL_CONFIG "config"
292 #define DMU_POOL_FEATURES_FOR_WRITE "features_for_write"
293 #define DMU_POOL_FEATURES_FOR_READ "features_for_read"
294 #define DMU_POOL_FEATURE_DESCRIPTIONS "feature_descriptions"
295 #define DMU_POOL_ROOT_DATASET "root_dataset"
296 #define DMU_POOL_SYNC_BPOBJ "sync_bplist"
297 #define DMU_POOL_ERRLOG_SCRUB "errlog_scrub"
298 #define DMU_POOL_ERRLOG_LAST "errlog_last"
299 #define DMU_POOL_SPARES "spares"
300 #define DMU_POOL_DEFLATE "deflate"
301 #define DMU_POOL_HISTORY "history"
302 #define DMU_POOL_PROPS "pool_props"
303 #define DMU_POOL_L2CACHE "l2cache"
304 #define DMU_POOL_TMP_USERREFS "tmp_userrefs"
305 #define DMU_POOL_DDT "DDT-%s-%s-%s"
306 #define DMU_POOL_DDT_STATS "DDT-statistics"
307 #define DMU_POOL_CREATION_VERSION "creation_version"
308 #define DMU_POOL_SCAN "scan"
309 #define DMU_POOL_FREE_BPOBJ "free_bpobj"
310 #define DMU_POOL_BPTREE_OBJ "bptree_obj"
311 #define DMU_POOL_EMPTY_BPOBJ "empty_bpobj"
312
313 /*
314 * Allocate an object from this objset. The range of object numbers
315 * available is (0, DN_MAX_OBJECT). Object 0 is the meta-dnode.
316 *
317 * The transaction must be assigned to a txg. The newly allocated
318 * object will be "held" in the transaction (ie. you can modify the
319 * newly allocated object in this transaction).
320 *
321 * dmu_object_alloc() chooses an object and returns it in *objectp.
322 *
323 * dmu_object_claim() allocates a specific object number. If that
324 * number is already allocated, it fails and returns EEXIST.
325 *
326 * Return 0 on success, or ENOSPC or EEXIST as specified above.
327 */
328 uint64_t dmu_object_alloc(objset_t *os, dmu_object_type_t ot,
329 int blocksize, dmu_object_type_t bonus_type, int bonus_len, dmu_tx_t *tx);
330 int dmu_object_claim(objset_t *os, uint64_t object, dmu_object_type_t ot,
331 int blocksize, dmu_object_type_t bonus_type, int bonus_len, dmu_tx_t *tx);
332 int dmu_object_reclaim(objset_t *os, uint64_t object, dmu_object_type_t ot,
333 int blocksize, dmu_object_type_t bonustype, int bonuslen);
334
335 /*
336 * Free an object from this objset.
337 *
338 * The object's data will be freed as well (ie. you don't need to call
339 * dmu_free(object, 0, -1, tx)).
340 *
341 * The object need not be held in the transaction.
342 *
343 * If there are any holds on this object's buffers (via dmu_buf_hold()),
344 * or tx holds on the object (via dmu_tx_hold_object()), you can not
345 * free it; it fails and returns EBUSY.
346 *
347 * If the object is not allocated, it fails and returns ENOENT.
348 *
349 * Return 0 on success, or EBUSY or ENOENT as specified above.
350 */
351 int dmu_object_free(objset_t *os, uint64_t object, dmu_tx_t *tx);
352
353 /*
354 * Find the next allocated or free object.
355 *
356 * The objectp parameter is in-out. It will be updated to be the next
357 * object which is allocated. Ignore objects which have not been
358 * modified since txg.
359 *
360 * XXX Can only be called on a objset with no dirty data.
361 *
362 * Returns 0 on success, or ENOENT if there are no more objects.
363 */
364 int dmu_object_next(objset_t *os, uint64_t *objectp,
365 boolean_t hole, uint64_t txg);
366
367 /*
368 * Set the data blocksize for an object.
369 *
370 * The object cannot have any blocks allcated beyond the first. If
371 * the first block is allocated already, the new size must be greater
372 * than the current block size. If these conditions are not met,
373 * ENOTSUP will be returned.
374 *
375 * Returns 0 on success, or EBUSY if there are any holds on the object
376 * contents, or ENOTSUP as described above.
377 */
378 int dmu_object_set_blocksize(objset_t *os, uint64_t object, uint64_t size,
379 int ibs, dmu_tx_t *tx);
380
381 /*
382 * Set the checksum property on a dnode. The new checksum algorithm will
383 * apply to all newly written blocks; existing blocks will not be affected.
384 */
385 void dmu_object_set_checksum(objset_t *os, uint64_t object, uint8_t checksum,
386 dmu_tx_t *tx);
387
388 /*
389 * Set the compress property on a dnode. The new compression algorithm will
390 * apply to all newly written blocks; existing blocks will not be affected.
391 */
392 void dmu_object_set_compress(objset_t *os, uint64_t object, uint8_t compress,
393 dmu_tx_t *tx);
394
395 /*
396 * Decide how to write a block: checksum, compression, number of copies, etc.
397 */
398 #define WP_NOFILL 0x1
399 #define WP_DMU_SYNC 0x2
400 #define WP_SPILL 0x4
401
402 void dmu_write_policy(objset_t *os, struct dnode *dn, int level, int wp,
403 struct zio_prop *zp);
404 /*
405 * The bonus data is accessed more or less like a regular buffer.
406 * You must dmu_bonus_hold() to get the buffer, which will give you a
407 * dmu_buf_t with db_offset==-1ULL, and db_size = the size of the bonus
408 * data. As with any normal buffer, you must call dmu_buf_read() to
409 * read db_data, dmu_buf_will_dirty() before modifying it, and the
410 * object must be held in an assigned transaction before calling
411 * dmu_buf_will_dirty. You may use dmu_buf_set_user() on the bonus
412 * buffer as well. You must release your hold with dmu_buf_rele().
413 *
414 * Returns ENOENT, EIO, or 0.
415 */
416 int dmu_bonus_hold(objset_t *os, uint64_t object, void *tag, dmu_buf_t **);
417 int dmu_bonus_max(void);
418 int dmu_set_bonus(dmu_buf_t *, int, dmu_tx_t *);
419 int dmu_set_bonustype(dmu_buf_t *, dmu_object_type_t, dmu_tx_t *);
420 dmu_object_type_t dmu_get_bonustype(dmu_buf_t *);
421 int dmu_rm_spill(objset_t *, uint64_t, dmu_tx_t *);
422
423 /*
424 * Special spill buffer support used by "SA" framework
425 */
426
427 int dmu_spill_hold_by_bonus(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp);
428 int dmu_spill_hold_by_dnode(struct dnode *dn, uint32_t flags,
429 void *tag, dmu_buf_t **dbp);
430 int dmu_spill_hold_existing(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp);
431
432 /*
433 * Obtain the DMU buffer from the specified object which contains the
434 * specified offset. dmu_buf_hold() puts a "hold" on the buffer, so
435 * that it will remain in memory. You must release the hold with
436 * dmu_buf_rele(). You musn't access the dmu_buf_t after releasing your
437 * hold. You must have a hold on any dmu_buf_t* you pass to the DMU.
438 *
439 * You must call dmu_buf_read, dmu_buf_will_dirty, or dmu_buf_will_fill
440 * on the returned buffer before reading or writing the buffer's
441 * db_data. The comments for those routines describe what particular
442 * operations are valid after calling them.
443 *
444 * The object number must be a valid, allocated object number.
445 */
446 int dmu_buf_hold(objset_t *os, uint64_t object, uint64_t offset,
447 void *tag, dmu_buf_t **, int flags);
448 void dmu_buf_add_ref(dmu_buf_t *db, void* tag);
449 void dmu_buf_rele(dmu_buf_t *db, void *tag);
450 uint64_t dmu_buf_refcount(dmu_buf_t *db);
451
452 /*
453 * dmu_buf_hold_array holds the DMU buffers which contain all bytes in a
454 * range of an object. A pointer to an array of dmu_buf_t*'s is
455 * returned (in *dbpp).
456 *
457 * dmu_buf_rele_array releases the hold on an array of dmu_buf_t*'s, and
458 * frees the array. The hold on the array of buffers MUST be released
459 * with dmu_buf_rele_array. You can NOT release the hold on each buffer
460 * individually with dmu_buf_rele.
461 */
462 int dmu_buf_hold_array_by_bonus(dmu_buf_t *db, uint64_t offset,
463 uint64_t length, int read, void *tag, int *numbufsp, dmu_buf_t ***dbpp);
464 void dmu_buf_rele_array(dmu_buf_t **, int numbufs, void *tag);
465
466 /*
467 * Returns NULL on success, or the existing user ptr if it's already
468 * been set.
469 *
470 * user_ptr is for use by the user and can be obtained via dmu_buf_get_user().
471 *
472 * user_data_ptr_ptr should be NULL, or a pointer to a pointer which
473 * will be set to db->db_data when you are allowed to access it. Note
474 * that db->db_data (the pointer) can change when you do dmu_buf_read(),
475 * dmu_buf_tryupgrade(), dmu_buf_will_dirty(), or dmu_buf_will_fill().
476 * *user_data_ptr_ptr will be set to the new value when it changes.
477 *
478 * If non-NULL, pageout func will be called when this buffer is being
479 * excised from the cache, so that you can clean up the data structure
480 * pointed to by user_ptr.
481 *
482 * dmu_evict_user() will call the pageout func for all buffers in a
483 * objset with a given pageout func.
484 */
485 void *dmu_buf_set_user(dmu_buf_t *db, void *user_ptr, void *user_data_ptr_ptr,
486 dmu_buf_evict_func_t *pageout_func);
487 /*
488 * set_user_ie is the same as set_user, but request immediate eviction
489 * when hold count goes to zero.
490 */
491 void *dmu_buf_set_user_ie(dmu_buf_t *db, void *user_ptr,
492 void *user_data_ptr_ptr, dmu_buf_evict_func_t *pageout_func);
493 void *dmu_buf_update_user(dmu_buf_t *db_fake, void *old_user_ptr,
494 void *user_ptr, void *user_data_ptr_ptr,
495 dmu_buf_evict_func_t *pageout_func);
496 void dmu_evict_user(objset_t *os, dmu_buf_evict_func_t *func);
497
498 /*
499 * Returns the user_ptr set with dmu_buf_set_user(), or NULL if not set.
500 */
501 void *dmu_buf_get_user(dmu_buf_t *db);
502
503 /*
504 * Returns the blkptr associated with this dbuf, or NULL if not set.
505 */
506 struct blkptr *dmu_buf_get_blkptr(dmu_buf_t *db);
507
508 /*
509 * Indicate that you are going to modify the buffer's data (db_data).
510 *
511 * The transaction (tx) must be assigned to a txg (ie. you've called
512 * dmu_tx_assign()). The buffer's object must be held in the tx
513 * (ie. you've called dmu_tx_hold_object(tx, db->db_object)).
514 */
515 void dmu_buf_will_dirty(dmu_buf_t *db, dmu_tx_t *tx);
516
517 /*
518 * Tells if the given dbuf is freeable.
519 */
520 boolean_t dmu_buf_freeable(dmu_buf_t *);
521
522 /*
523 * You must create a transaction, then hold the objects which you will
524 * (or might) modify as part of this transaction. Then you must assign
525 * the transaction to a transaction group. Once the transaction has
526 * been assigned, you can modify buffers which belong to held objects as
527 * part of this transaction. You can't modify buffers before the
528 * transaction has been assigned; you can't modify buffers which don't
529 * belong to objects which this transaction holds; you can't hold
530 * objects once the transaction has been assigned. You may hold an
531 * object which you are going to free (with dmu_object_free()), but you
532 * don't have to.
533 *
534 * You can abort the transaction before it has been assigned.
535 *
536 * Note that you may hold buffers (with dmu_buf_hold) at any time,
537 * regardless of transaction state.
538 */
539
540 #define DMU_NEW_OBJECT (-1ULL)
541 #define DMU_OBJECT_END (-1ULL)
542
543 dmu_tx_t *dmu_tx_create(objset_t *os);
544 void dmu_tx_hold_write(dmu_tx_t *tx, uint64_t object, uint64_t off, int len);
545 void dmu_tx_hold_free(dmu_tx_t *tx, uint64_t object, uint64_t off,
546 uint64_t len);
547 void dmu_tx_hold_zap(dmu_tx_t *tx, uint64_t object, int add, const char *name);
548 void dmu_tx_hold_bonus(dmu_tx_t *tx, uint64_t object);
549 void dmu_tx_hold_spill(dmu_tx_t *tx, uint64_t object);
550 void dmu_tx_hold_sa(dmu_tx_t *tx, struct sa_handle *hdl, boolean_t may_grow);
551 void dmu_tx_hold_sa_create(dmu_tx_t *tx, int total_size);
552 void dmu_tx_abort(dmu_tx_t *tx);
553 int dmu_tx_assign(dmu_tx_t *tx, enum txg_how txg_how);
554 void dmu_tx_wait(dmu_tx_t *tx);
555 void dmu_tx_commit(dmu_tx_t *tx);
556
557 /*
558 * To register a commit callback, dmu_tx_callback_register() must be called.
559 *
560 * dcb_data is a pointer to caller private data that is passed on as a
561 * callback parameter. The caller is responsible for properly allocating and
562 * freeing it.
563 *
564 * When registering a callback, the transaction must be already created, but
565 * it cannot be committed or aborted. It can be assigned to a txg or not.
566 *
567 * The callback will be called after the transaction has been safely written
568 * to stable storage and will also be called if the dmu_tx is aborted.
569 * If there is any error which prevents the transaction from being committed to
570 * disk, the callback will be called with a value of error != 0.
571 */
572 typedef void dmu_tx_callback_func_t(void *dcb_data, int error);
573
574 void dmu_tx_callback_register(dmu_tx_t *tx, dmu_tx_callback_func_t *dcb_func,
575 void *dcb_data);
576
577 /*
578 * Free up the data blocks for a defined range of a file. If size is
579 * -1, the range from offset to end-of-file is freed.
580 */
581 int dmu_free_range(objset_t *os, uint64_t object, uint64_t offset,
582 uint64_t size, dmu_tx_t *tx);
583 int dmu_free_long_range(objset_t *os, uint64_t object, uint64_t offset,
584 uint64_t size);
585 int dmu_free_long_object(objset_t *os, uint64_t object);
586
587 /*
588 * Convenience functions.
589 *
590 * Canfail routines will return 0 on success, or an errno if there is a
591 * nonrecoverable I/O error.
592 */
593 #define DMU_READ_PREFETCH 0 /* prefetch */
594 #define DMU_READ_NO_PREFETCH 1 /* don't prefetch */
595 int dmu_read(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
596 void *buf, uint32_t flags);
597 void dmu_write(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
598 const void *buf, dmu_tx_t *tx);
599 void dmu_prealloc(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
600 dmu_tx_t *tx);
601 int dmu_read_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size);
602 int dmu_write_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size,
603 dmu_tx_t *tx);
604 int dmu_write_uio_dbuf(dmu_buf_t *zdb, struct uio *uio, uint64_t size,
605 dmu_tx_t *tx);
606 int dmu_write_pages(objset_t *os, uint64_t object, uint64_t offset,
607 uint64_t size, struct page *pp, dmu_tx_t *tx);
608 struct arc_buf *dmu_request_arcbuf(dmu_buf_t *handle, int size);
609 void dmu_return_arcbuf(struct arc_buf *buf);
610 void dmu_assign_arcbuf(dmu_buf_t *handle, uint64_t offset, struct arc_buf *buf,
611 dmu_tx_t *tx);
612 int dmu_xuio_init(struct xuio *uio, int niov);
613 void dmu_xuio_fini(struct xuio *uio);
614 int dmu_xuio_add(struct xuio *uio, struct arc_buf *abuf, offset_t off,
615 size_t n);
616 int dmu_xuio_cnt(struct xuio *uio);
617 struct arc_buf *dmu_xuio_arcbuf(struct xuio *uio, int i);
618 void dmu_xuio_clear(struct xuio *uio, int i);
619 void xuio_stat_wbuf_copied();
620 void xuio_stat_wbuf_nocopy();
621
622 extern int zfs_prefetch_disable;
623
624 /*
625 * Asynchronously try to read in the data.
626 */
627 void dmu_prefetch(objset_t *os, uint64_t object, uint64_t offset,
628 uint64_t len);
629
630 typedef struct dmu_object_info {
631 /* All sizes are in bytes unless otherwise indicated. */
632 uint32_t doi_data_block_size;
633 uint32_t doi_metadata_block_size;
634 dmu_object_type_t doi_type;
635 dmu_object_type_t doi_bonus_type;
636 uint64_t doi_bonus_size;
637 uint8_t doi_indirection; /* 2 = dnode->indirect->data */
638 uint8_t doi_checksum;
639 uint8_t doi_compress;
640 uint8_t doi_pad[5];
641 uint64_t doi_physical_blocks_512; /* data + metadata, 512b blks */
642 uint64_t doi_max_offset;
643 uint64_t doi_fill_count; /* number of non-empty blocks */
644 } dmu_object_info_t;
645
646 typedef void arc_byteswap_func_t(void *buf, size_t size);
647
648 typedef struct dmu_object_type_info {
649 dmu_object_byteswap_t ot_byteswap;
650 boolean_t ot_metadata;
651 char *ot_name;
652 } dmu_object_type_info_t;
653
654 typedef struct dmu_object_byteswap_info {
655 arc_byteswap_func_t *ob_func;
656 char *ob_name;
657 } dmu_object_byteswap_info_t;
658
659 extern const dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES];
660 extern const dmu_object_byteswap_info_t dmu_ot_byteswap[DMU_BSWAP_NUMFUNCS];
661
662 /*
663 * Get information on a DMU object.
664 *
665 * Return 0 on success or ENOENT if object is not allocated.
666 *
667 * If doi is NULL, just indicates whether the object exists.
668 */
669 int dmu_object_info(objset_t *os, uint64_t object, dmu_object_info_t *doi);
670 /* Like dmu_object_info, but faster if you have a held dnode in hand. */
671 void dmu_object_info_from_dnode(struct dnode *dn, dmu_object_info_t *doi);
672 /* Like dmu_object_info, but faster if you have a held dbuf in hand. */
673 void dmu_object_info_from_db(dmu_buf_t *db, dmu_object_info_t *doi);
674 /*
675 * Like dmu_object_info_from_db, but faster still when you only care about
676 * the size. This is specifically optimized for zfs_getattr().
677 */
678 void dmu_object_size_from_db(dmu_buf_t *db, uint32_t *blksize,
679 u_longlong_t *nblk512);
680
681 typedef struct dmu_objset_stats {
682 uint64_t dds_num_clones; /* number of clones of this */
683 uint64_t dds_creation_txg;
684 uint64_t dds_guid;
685 dmu_objset_type_t dds_type;
686 uint8_t dds_is_snapshot;
687 uint8_t dds_inconsistent;
688 char dds_origin[MAXNAMELEN];
689 } dmu_objset_stats_t;
690
691 /*
692 * Get stats on a dataset.
693 */
694 void dmu_objset_fast_stat(objset_t *os, dmu_objset_stats_t *stat);
695
696 /*
697 * Add entries to the nvlist for all the objset's properties. See
698 * zfs_prop_table[] and zfs(1m) for details on the properties.
699 */
700 void dmu_objset_stats(objset_t *os, struct nvlist *nv);
701
702 /*
703 * Get the space usage statistics for statvfs().
704 *
705 * refdbytes is the amount of space "referenced" by this objset.
706 * availbytes is the amount of space available to this objset, taking
707 * into account quotas & reservations, assuming that no other objsets
708 * use the space first. These values correspond to the 'referenced' and
709 * 'available' properties, described in the zfs(1m) manpage.
710 *
711 * usedobjs and availobjs are the number of objects currently allocated,
712 * and available.
713 */
714 void dmu_objset_space(objset_t *os, uint64_t *refdbytesp, uint64_t *availbytesp,
715 uint64_t *usedobjsp, uint64_t *availobjsp);
716
717 /*
718 * The fsid_guid is a 56-bit ID that can change to avoid collisions.
719 * (Contrast with the ds_guid which is a 64-bit ID that will never
720 * change, so there is a small probability that it will collide.)
721 */
722 uint64_t dmu_objset_fsid_guid(objset_t *os);
723
724 /*
725 * Get the [cm]time for an objset's snapshot dir
726 */
727 timestruc_t dmu_objset_snap_cmtime(objset_t *os);
728
729 int dmu_objset_is_snapshot(objset_t *os);
730
731 extern struct spa *dmu_objset_spa(objset_t *os);
732 extern struct zilog *dmu_objset_zil(objset_t *os);
733 extern struct dsl_pool *dmu_objset_pool(objset_t *os);
734 extern struct dsl_dataset *dmu_objset_ds(objset_t *os);
735 extern void dmu_objset_name(objset_t *os, char *buf);
736 extern dmu_objset_type_t dmu_objset_type(objset_t *os);
737 extern uint64_t dmu_objset_id(objset_t *os);
738 extern uint64_t dmu_objset_syncprop(objset_t *os);
739 extern uint64_t dmu_objset_logbias(objset_t *os);
740 extern int dmu_snapshot_list_next(objset_t *os, int namelen, char *name,
741 uint64_t *id, uint64_t *offp, boolean_t *case_conflict);
742 extern int dmu_snapshot_realname(objset_t *os, char *name, char *real,
743 int maxlen, boolean_t *conflict);
744 extern int dmu_dir_list_next(objset_t *os, int namelen, char *name,
745 uint64_t *idp, uint64_t *offp);
746
747 typedef int objset_used_cb_t(dmu_object_type_t bonustype,
748 void *bonus, uint64_t *userp, uint64_t *groupp);
749 extern void dmu_objset_register_type(dmu_objset_type_t ost,
750 objset_used_cb_t *cb);
751 extern void dmu_objset_set_user(objset_t *os, void *user_ptr);
752 extern void *dmu_objset_get_user(objset_t *os);
753
754 /*
755 * Return the txg number for the given assigned transaction.
756 */
757 uint64_t dmu_tx_get_txg(dmu_tx_t *tx);
758
759 /*
760 * Synchronous write.
761 * If a parent zio is provided this function initiates a write on the
762 * provided buffer as a child of the parent zio.
763 * In the absence of a parent zio, the write is completed synchronously.
764 * At write completion, blk is filled with the bp of the written block.
765 * Note that while the data covered by this function will be on stable
766 * storage when the write completes this new data does not become a
767 * permanent part of the file until the associated transaction commits.
768 */
769
770 /*
771 * {zfs,zvol,ztest}_get_done() args
772 */
773 typedef struct zgd {
774 struct zilog *zgd_zilog;
775 struct blkptr *zgd_bp;
776 dmu_buf_t *zgd_db;
777 struct rl *zgd_rl;
778 void *zgd_private;
779 } zgd_t;
780
781 typedef void dmu_sync_cb_t(zgd_t *arg, int error);
782 int dmu_sync(struct zio *zio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd);
783
784 /*
785 * Find the next hole or data block in file starting at *off
786 * Return found offset in *off. Return ESRCH for end of file.
787 */
788 int dmu_offset_next(objset_t *os, uint64_t object, boolean_t hole,
789 uint64_t *off);
790
791 /*
792 * Initial setup and final teardown.
793 */
794 extern void dmu_init(void);
795 extern void dmu_fini(void);
796
797 typedef void (*dmu_traverse_cb_t)(objset_t *os, void *arg, struct blkptr *bp,
798 uint64_t object, uint64_t offset, int len);
799 void dmu_traverse_objset(objset_t *os, uint64_t txg_start,
800 dmu_traverse_cb_t cb, void *arg);
801
802 int dmu_diff(const char *tosnap_name, const char *fromsnap_name,
803 struct vnode *vp, offset_t *offp);
804
805 /* CRC64 table */
806 #define ZFS_CRC64_POLY 0xC96C5795D7870F42ULL /* ECMA-182, reflected form */
807 extern uint64_t zfs_crc64_table[256];
808
809 #ifdef __cplusplus
810 }
811 #endif
812
813 #endif /* _SYS_DMU_H */