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 * Copyright 2013 Saso Kiselkov. All rights reserved.
28 */
29
30 /* Portions Copyright 2010 Robert Milkowski */
31
32 #ifndef _SYS_DMU_H
33 #define _SYS_DMU_H
34
35 /*
36 * This file describes the interface that the DMU provides for its
37 * consumers.
38 *
39 * The DMU also interacts with the SPA. That interface is described in
40 * dmu_spa.h.
41 */
42
43 #include <sys/inttypes.h>
44 #include <sys/types.h>
45 #include <sys/param.h>
46 #include <sys/cred.h>
47 #include <sys/time.h>
48 #include <sys/fs/zfs.h>
49
50 #ifdef __cplusplus
51 extern "C" {
52 #endif
53
54 struct uio;
55 struct xuio;
56 struct page;
57 struct vnode;
58 struct spa;
59 struct zilog;
60 struct zio;
61 struct blkptr;
62 struct zap_cursor;
63 struct dsl_dataset;
64 struct dsl_pool;
65 struct dnode;
66 struct drr_begin;
67 struct drr_end;
68 struct zbookmark;
69 struct spa;
70 struct nvlist;
71 struct arc_buf;
72 struct zio_prop;
73 struct sa_handle;
74
75 typedef struct objset objset_t;
76 typedef struct dmu_tx dmu_tx_t;
77 typedef struct dsl_dir dsl_dir_t;
78
79 typedef enum dmu_object_byteswap {
80 DMU_BSWAP_UINT8,
81 DMU_BSWAP_UINT16,
82 DMU_BSWAP_UINT32,
83 DMU_BSWAP_UINT64,
84 DMU_BSWAP_ZAP,
85 DMU_BSWAP_DNODE,
86 DMU_BSWAP_OBJSET,
87 DMU_BSWAP_ZNODE,
88 DMU_BSWAP_OLDACL,
89 DMU_BSWAP_ACL,
90 /*
91 * Allocating a new byteswap type number makes the on-disk format
92 * incompatible with any other format that uses the same number.
93 *
94 * Data can usually be structured to work with one of the
95 * DMU_BSWAP_UINT* or DMU_BSWAP_ZAP types.
96 */
97 DMU_BSWAP_NUMFUNCS
98 } dmu_object_byteswap_t;
99
100 #define DMU_OT_NEWTYPE 0x80
101 #define DMU_OT_METADATA 0x40
102 #define DMU_OT_BYTESWAP_MASK 0x3f
103
104 /*
105 * Defines a uint8_t object type. Object types specify if the data
106 * in the object is metadata (boolean) and how to byteswap the data
107 * (dmu_object_byteswap_t).
108 */
109 #define DMU_OT(byteswap, metadata) \
110 (DMU_OT_NEWTYPE | \
111 ((metadata) ? DMU_OT_METADATA : 0) | \
112 ((byteswap) & DMU_OT_BYTESWAP_MASK))
113
114 #define DMU_OT_IS_VALID(ot) (((ot) & DMU_OT_NEWTYPE) ? \
115 ((ot) & DMU_OT_BYTESWAP_MASK) < DMU_BSWAP_NUMFUNCS : \
116 (ot) < DMU_OT_NUMTYPES)
117
118 #define DMU_OT_IS_METADATA(ot) (((ot) & DMU_OT_NEWTYPE) ? \
119 ((ot) & DMU_OT_METADATA) : \
120 dmu_ot[(ot)].ot_metadata)
121
122 #define DMU_OT_BYTESWAP(ot) (((ot) & DMU_OT_NEWTYPE) ? \
123 ((ot) & DMU_OT_BYTESWAP_MASK) : \
124 dmu_ot[(ot)].ot_byteswap)
125
126 typedef enum dmu_object_type {
127 DMU_OT_NONE,
128 /* general: */
129 DMU_OT_OBJECT_DIRECTORY, /* ZAP */
130 DMU_OT_OBJECT_ARRAY, /* UINT64 */
131 DMU_OT_PACKED_NVLIST, /* UINT8 (XDR by nvlist_pack/unpack) */
132 DMU_OT_PACKED_NVLIST_SIZE, /* UINT64 */
133 DMU_OT_BPOBJ, /* UINT64 */
134 DMU_OT_BPOBJ_HDR, /* UINT64 */
135 /* spa: */
136 DMU_OT_SPACE_MAP_HEADER, /* UINT64 */
137 DMU_OT_SPACE_MAP, /* UINT64 */
138 /* zil: */
139 DMU_OT_INTENT_LOG, /* UINT64 */
140 /* dmu: */
141 DMU_OT_DNODE, /* DNODE */
142 DMU_OT_OBJSET, /* OBJSET */
143 /* dsl: */
144 DMU_OT_DSL_DIR, /* UINT64 */
145 DMU_OT_DSL_DIR_CHILD_MAP, /* ZAP */
146 DMU_OT_DSL_DS_SNAP_MAP, /* ZAP */
147 DMU_OT_DSL_PROPS, /* ZAP */
148 DMU_OT_DSL_DATASET, /* UINT64 */
149 /* zpl: */
150 DMU_OT_ZNODE, /* ZNODE */
151 DMU_OT_OLDACL, /* Old ACL */
152 DMU_OT_PLAIN_FILE_CONTENTS, /* UINT8 */
153 DMU_OT_DIRECTORY_CONTENTS, /* ZAP */
154 DMU_OT_MASTER_NODE, /* ZAP */
155 DMU_OT_UNLINKED_SET, /* ZAP */
156 /* zvol: */
157 DMU_OT_ZVOL, /* UINT8 */
158 DMU_OT_ZVOL_PROP, /* ZAP */
159 /* other; for testing only! */
160 DMU_OT_PLAIN_OTHER, /* UINT8 */
161 DMU_OT_UINT64_OTHER, /* UINT64 */
162 DMU_OT_ZAP_OTHER, /* ZAP */
163 /* new object types: */
164 DMU_OT_ERROR_LOG, /* ZAP */
165 DMU_OT_SPA_HISTORY, /* UINT8 */
166 DMU_OT_SPA_HISTORY_OFFSETS, /* spa_his_phys_t */
167 DMU_OT_POOL_PROPS, /* ZAP */
168 DMU_OT_DSL_PERMS, /* ZAP */
169 DMU_OT_ACL, /* ACL */
170 DMU_OT_SYSACL, /* SYSACL */
171 DMU_OT_FUID, /* FUID table (Packed NVLIST UINT8) */
172 DMU_OT_FUID_SIZE, /* FUID table size UINT64 */
173 DMU_OT_NEXT_CLONES, /* ZAP */
174 DMU_OT_SCAN_QUEUE, /* ZAP */
175 DMU_OT_USERGROUP_USED, /* ZAP */
176 DMU_OT_USERGROUP_QUOTA, /* ZAP */
177 DMU_OT_USERREFS, /* ZAP */
178 DMU_OT_DDT_ZAP, /* ZAP */
179 DMU_OT_DDT_STATS, /* ZAP */
180 DMU_OT_SA, /* System attr */
181 DMU_OT_SA_MASTER_NODE, /* ZAP */
182 DMU_OT_SA_ATTR_REGISTRATION, /* ZAP */
183 DMU_OT_SA_ATTR_LAYOUTS, /* ZAP */
184 DMU_OT_SCAN_XLATE, /* ZAP */
185 DMU_OT_DEDUP, /* fake dedup BP from ddt_bp_create() */
186 DMU_OT_DEADLIST, /* ZAP */
187 DMU_OT_DEADLIST_HDR, /* UINT64 */
188 DMU_OT_DSL_CLONES, /* ZAP */
189 DMU_OT_BPOBJ_SUBOBJ, /* UINT64 */
190 /*
191 * Do not allocate new object types here. Doing so makes the on-disk
192 * format incompatible with any other format that uses the same object
193 * type number.
194 *
195 * When creating an object which does not have one of the above types
196 * use the DMU_OTN_* type with the correct byteswap and metadata
197 * values.
198 *
199 * The DMU_OTN_* types do not have entries in the dmu_ot table,
200 * use the DMU_OT_IS_METDATA() and DMU_OT_BYTESWAP() macros instead
201 * of indexing into dmu_ot directly (this works for both DMU_OT_* types
202 * and DMU_OTN_* types).
203 */
204 DMU_OT_NUMTYPES,
205
206 /*
207 * Names for valid types declared with DMU_OT().
208 */
209 DMU_OTN_UINT8_DATA = DMU_OT(DMU_BSWAP_UINT8, B_FALSE),
210 DMU_OTN_UINT8_METADATA = DMU_OT(DMU_BSWAP_UINT8, B_TRUE),
211 DMU_OTN_UINT16_DATA = DMU_OT(DMU_BSWAP_UINT16, B_FALSE),
212 DMU_OTN_UINT16_METADATA = DMU_OT(DMU_BSWAP_UINT16, B_TRUE),
213 DMU_OTN_UINT32_DATA = DMU_OT(DMU_BSWAP_UINT32, B_FALSE),
214 DMU_OTN_UINT32_METADATA = DMU_OT(DMU_BSWAP_UINT32, B_TRUE),
215 DMU_OTN_UINT64_DATA = DMU_OT(DMU_BSWAP_UINT64, B_FALSE),
216 DMU_OTN_UINT64_METADATA = DMU_OT(DMU_BSWAP_UINT64, B_TRUE),
217 DMU_OTN_ZAP_DATA = DMU_OT(DMU_BSWAP_ZAP, B_FALSE),
218 DMU_OTN_ZAP_METADATA = DMU_OT(DMU_BSWAP_ZAP, B_TRUE),
219 } dmu_object_type_t;
220
221 typedef enum txg_how {
222 TXG_WAIT = 1,
223 TXG_NOWAIT,
224 TXG_WAITED,
225 } txg_how_t;
226
227 void byteswap_uint64_array(void *buf, size_t size);
228 void byteswap_uint32_array(void *buf, size_t size);
229 void byteswap_uint16_array(void *buf, size_t size);
230 void byteswap_uint8_array(void *buf, size_t size);
231 void zap_byteswap(void *buf, size_t size);
232 void zfs_oldacl_byteswap(void *buf, size_t size);
233 void zfs_acl_byteswap(void *buf, size_t size);
234 void zfs_znode_byteswap(void *buf, size_t size);
235
236 #define DS_FIND_SNAPSHOTS (1<<0)
237 #define DS_FIND_CHILDREN (1<<1)
238
239 /*
240 * The maximum number of bytes that can be accessed as part of one
241 * operation, including metadata.
242 */
243 #define DMU_MAX_ACCESS (10<<20) /* 10MB */
244 #define DMU_MAX_DELETEBLKCNT (20480) /* ~5MB of indirect blocks */
245
246 #define DMU_USERUSED_OBJECT (-1ULL)
247 #define DMU_GROUPUSED_OBJECT (-2ULL)
248 #define DMU_DEADLIST_OBJECT (-3ULL)
249
250 /*
251 * artificial blkids for bonus buffer and spill blocks
252 */
253 #define DMU_BONUS_BLKID (-1ULL)
254 #define DMU_SPILL_BLKID (-2ULL)
255 /*
256 * Public routines to create, destroy, open, and close objsets.
257 */
258 int dmu_objset_hold(const char *name, void *tag, objset_t **osp);
259 int dmu_objset_own(const char *name, dmu_objset_type_t type,
260 boolean_t readonly, void *tag, objset_t **osp);
261 void dmu_objset_rele(objset_t *os, void *tag);
262 void dmu_objset_disown(objset_t *os, void *tag);
263 int dmu_objset_open_ds(struct dsl_dataset *ds, objset_t **osp);
264
265 void dmu_objset_evict_dbufs(objset_t *os);
266 int dmu_objset_create(const char *name, dmu_objset_type_t type, uint64_t flags,
267 void (*func)(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx), void *arg);
268 int dmu_objset_clone(const char *name, const char *origin);
269 int dsl_destroy_snapshots_nvl(struct nvlist *snaps, boolean_t defer,
270 struct nvlist *errlist);
271 int dmu_objset_snapshot_one(const char *fsname, const char *snapname);
272 int dmu_objset_snapshot_tmp(const char *, const char *, int);
273 int dmu_objset_find(char *name, int func(const char *, void *), void *arg,
274 int flags);
275 void dmu_objset_byteswap(void *buf, size_t size);
276 int dsl_dataset_rename_snapshot(const char *fsname,
277 const char *oldsnapname, const char *newsnapname, boolean_t recursive);
278
279 typedef struct dmu_buf {
280 uint64_t db_object; /* object that this buffer is part of */
281 uint64_t db_offset; /* byte offset in this object */
282 uint64_t db_size; /* size of buffer in bytes */
283 void *db_data; /* data in buffer */
284 } dmu_buf_t;
285
286 typedef void dmu_buf_evict_func_t(struct dmu_buf *db, void *user_ptr);
287
288 /*
289 * The names of zap entries in the DIRECTORY_OBJECT of the MOS.
290 */
291 #define DMU_POOL_DIRECTORY_OBJECT 1
292 #define DMU_POOL_CONFIG "config"
293 #define DMU_POOL_FEATURES_FOR_WRITE "features_for_write"
294 #define DMU_POOL_FEATURES_FOR_READ "features_for_read"
295 #define DMU_POOL_FEATURE_DESCRIPTIONS "feature_descriptions"
296 #define DMU_POOL_ROOT_DATASET "root_dataset"
297 #define DMU_POOL_SYNC_BPOBJ "sync_bplist"
298 #define DMU_POOL_ERRLOG_SCRUB "errlog_scrub"
299 #define DMU_POOL_ERRLOG_LAST "errlog_last"
300 #define DMU_POOL_SPARES "spares"
301 #define DMU_POOL_DEFLATE "deflate"
302 #define DMU_POOL_HISTORY "history"
303 #define DMU_POOL_PROPS "pool_props"
304 #define DMU_POOL_L2CACHE "l2cache"
305 #define DMU_POOL_TMP_USERREFS "tmp_userrefs"
306 #define DMU_POOL_DDT "DDT-%s-%s-%s"
307 #define DMU_POOL_DDT_STATS "DDT-statistics"
308 #define DMU_POOL_CREATION_VERSION "creation_version"
309 #define DMU_POOL_SCAN "scan"
310 #define DMU_POOL_FREE_BPOBJ "free_bpobj"
311 #define DMU_POOL_BPTREE_OBJ "bptree_obj"
312 #define DMU_POOL_EMPTY_BPOBJ "empty_bpobj"
313 #define DMU_POOL_CHECKSUM_SALT "checksum_salt"
314
315 /*
316 * Allocate an object from this objset. The range of object numbers
317 * available is (0, DN_MAX_OBJECT). Object 0 is the meta-dnode.
318 *
319 * The transaction must be assigned to a txg. The newly allocated
320 * object will be "held" in the transaction (ie. you can modify the
321 * newly allocated object in this transaction).
322 *
323 * dmu_object_alloc() chooses an object and returns it in *objectp.
324 *
325 * dmu_object_claim() allocates a specific object number. If that
326 * number is already allocated, it fails and returns EEXIST.
327 *
328 * Return 0 on success, or ENOSPC or EEXIST as specified above.
329 */
330 uint64_t dmu_object_alloc(objset_t *os, 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_claim(objset_t *os, uint64_t object, dmu_object_type_t ot,
333 int blocksize, dmu_object_type_t bonus_type, int bonus_len, dmu_tx_t *tx);
334 int dmu_object_reclaim(objset_t *os, uint64_t object, dmu_object_type_t ot,
335 int blocksize, dmu_object_type_t bonustype, int bonuslen);
336
337 /*
338 * Free an object from this objset.
339 *
340 * The object's data will be freed as well (ie. you don't need to call
341 * dmu_free(object, 0, -1, tx)).
342 *
343 * The object need not be held in the transaction.
344 *
345 * If there are any holds on this object's buffers (via dmu_buf_hold()),
346 * or tx holds on the object (via dmu_tx_hold_object()), you can not
347 * free it; it fails and returns EBUSY.
348 *
349 * If the object is not allocated, it fails and returns ENOENT.
350 *
351 * Return 0 on success, or EBUSY or ENOENT as specified above.
352 */
353 int dmu_object_free(objset_t *os, uint64_t object, dmu_tx_t *tx);
354
355 /*
356 * Find the next allocated or free object.
357 *
358 * The objectp parameter is in-out. It will be updated to be the next
359 * object which is allocated. Ignore objects which have not been
360 * modified since txg.
361 *
362 * XXX Can only be called on a objset with no dirty data.
363 *
364 * Returns 0 on success, or ENOENT if there are no more objects.
365 */
366 int dmu_object_next(objset_t *os, uint64_t *objectp,
367 boolean_t hole, uint64_t txg);
368
369 /*
370 * Set the data blocksize for an object.
371 *
372 * The object cannot have any blocks allcated beyond the first. If
373 * the first block is allocated already, the new size must be greater
374 * than the current block size. If these conditions are not met,
375 * ENOTSUP will be returned.
376 *
377 * Returns 0 on success, or EBUSY if there are any holds on the object
378 * contents, or ENOTSUP as described above.
379 */
380 int dmu_object_set_blocksize(objset_t *os, uint64_t object, uint64_t size,
381 int ibs, dmu_tx_t *tx);
382
383 /*
384 * Set the checksum property on a dnode. The new checksum algorithm will
385 * apply to all newly written blocks; existing blocks will not be affected.
386 */
387 void dmu_object_set_checksum(objset_t *os, uint64_t object, uint8_t checksum,
388 dmu_tx_t *tx);
389
390 /*
391 * Set the compress property on a dnode. The new compression algorithm will
392 * apply to all newly written blocks; existing blocks will not be affected.
393 */
394 void dmu_object_set_compress(objset_t *os, uint64_t object, uint8_t compress,
395 dmu_tx_t *tx);
396
397 /*
398 * Decide how to write a block: checksum, compression, number of copies, etc.
399 */
400 #define WP_NOFILL 0x1
401 #define WP_DMU_SYNC 0x2
402 #define WP_SPILL 0x4
403
404 void dmu_write_policy(objset_t *os, struct dnode *dn, int level, int wp,
405 struct zio_prop *zp);
406 /*
407 * The bonus data is accessed more or less like a regular buffer.
408 * You must dmu_bonus_hold() to get the buffer, which will give you a
409 * dmu_buf_t with db_offset==-1ULL, and db_size = the size of the bonus
410 * data. As with any normal buffer, you must call dmu_buf_read() to
411 * read db_data, dmu_buf_will_dirty() before modifying it, and the
412 * object must be held in an assigned transaction before calling
413 * dmu_buf_will_dirty. You may use dmu_buf_set_user() on the bonus
414 * buffer as well. You must release your hold with dmu_buf_rele().
415 *
416 * Returns ENOENT, EIO, or 0.
417 */
418 int dmu_bonus_hold(objset_t *os, uint64_t object, void *tag, dmu_buf_t **);
419 int dmu_bonus_max(void);
420 int dmu_set_bonus(dmu_buf_t *, int, dmu_tx_t *);
421 int dmu_set_bonustype(dmu_buf_t *, dmu_object_type_t, dmu_tx_t *);
422 dmu_object_type_t dmu_get_bonustype(dmu_buf_t *);
423 int dmu_rm_spill(objset_t *, uint64_t, dmu_tx_t *);
424
425 /*
426 * Special spill buffer support used by "SA" framework
427 */
428
429 int dmu_spill_hold_by_bonus(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp);
430 int dmu_spill_hold_by_dnode(struct dnode *dn, uint32_t flags,
431 void *tag, dmu_buf_t **dbp);
432 int dmu_spill_hold_existing(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp);
433
434 /*
435 * Obtain the DMU buffer from the specified object which contains the
436 * specified offset. dmu_buf_hold() puts a "hold" on the buffer, so
437 * that it will remain in memory. You must release the hold with
438 * dmu_buf_rele(). You musn't access the dmu_buf_t after releasing your
439 * hold. You must have a hold on any dmu_buf_t* you pass to the DMU.
440 *
441 * You must call dmu_buf_read, dmu_buf_will_dirty, or dmu_buf_will_fill
442 * on the returned buffer before reading or writing the buffer's
443 * db_data. The comments for those routines describe what particular
444 * operations are valid after calling them.
445 *
446 * The object number must be a valid, allocated object number.
447 */
448 int dmu_buf_hold(objset_t *os, uint64_t object, uint64_t offset,
449 void *tag, dmu_buf_t **, int flags);
450 void dmu_buf_add_ref(dmu_buf_t *db, void* tag);
451 void dmu_buf_rele(dmu_buf_t *db, void *tag);
452 uint64_t dmu_buf_refcount(dmu_buf_t *db);
453
454 /*
455 * dmu_buf_hold_array holds the DMU buffers which contain all bytes in a
456 * range of an object. A pointer to an array of dmu_buf_t*'s is
457 * returned (in *dbpp).
458 *
459 * dmu_buf_rele_array releases the hold on an array of dmu_buf_t*'s, and
460 * frees the array. The hold on the array of buffers MUST be released
461 * with dmu_buf_rele_array. You can NOT release the hold on each buffer
462 * individually with dmu_buf_rele.
463 */
464 int dmu_buf_hold_array_by_bonus(dmu_buf_t *db, uint64_t offset,
465 uint64_t length, int read, void *tag, int *numbufsp, dmu_buf_t ***dbpp);
466 void dmu_buf_rele_array(dmu_buf_t **, int numbufs, void *tag);
467
468 /*
469 * Returns NULL on success, or the existing user ptr if it's already
470 * been set.
471 *
472 * user_ptr is for use by the user and can be obtained via dmu_buf_get_user().
473 *
474 * user_data_ptr_ptr should be NULL, or a pointer to a pointer which
475 * will be set to db->db_data when you are allowed to access it. Note
476 * that db->db_data (the pointer) can change when you do dmu_buf_read(),
477 * dmu_buf_tryupgrade(), dmu_buf_will_dirty(), or dmu_buf_will_fill().
478 * *user_data_ptr_ptr will be set to the new value when it changes.
479 *
480 * If non-NULL, pageout func will be called when this buffer is being
481 * excised from the cache, so that you can clean up the data structure
482 * pointed to by user_ptr.
483 *
484 * dmu_evict_user() will call the pageout func for all buffers in a
485 * objset with a given pageout func.
486 */
487 void *dmu_buf_set_user(dmu_buf_t *db, void *user_ptr, void *user_data_ptr_ptr,
488 dmu_buf_evict_func_t *pageout_func);
489 /*
490 * set_user_ie is the same as set_user, but request immediate eviction
491 * when hold count goes to zero.
492 */
493 void *dmu_buf_set_user_ie(dmu_buf_t *db, void *user_ptr,
494 void *user_data_ptr_ptr, dmu_buf_evict_func_t *pageout_func);
495 void *dmu_buf_update_user(dmu_buf_t *db_fake, void *old_user_ptr,
496 void *user_ptr, void *user_data_ptr_ptr,
497 dmu_buf_evict_func_t *pageout_func);
498 void dmu_evict_user(objset_t *os, dmu_buf_evict_func_t *func);
499
500 /*
501 * Returns the user_ptr set with dmu_buf_set_user(), or NULL if not set.
502 */
503 void *dmu_buf_get_user(dmu_buf_t *db);
504
505 /*
506 * Returns the blkptr associated with this dbuf, or NULL if not set.
507 */
508 struct blkptr *dmu_buf_get_blkptr(dmu_buf_t *db);
509
510 /*
511 * Indicate that you are going to modify the buffer's data (db_data).
512 *
513 * The transaction (tx) must be assigned to a txg (ie. you've called
514 * dmu_tx_assign()). The buffer's object must be held in the tx
515 * (ie. you've called dmu_tx_hold_object(tx, db->db_object)).
516 */
517 void dmu_buf_will_dirty(dmu_buf_t *db, dmu_tx_t *tx);
518
519 /*
520 * Tells if the given dbuf is freeable.
521 */
522 boolean_t dmu_buf_freeable(dmu_buf_t *);
523
524 /*
525 * You must create a transaction, then hold the objects which you will
526 * (or might) modify as part of this transaction. Then you must assign
527 * the transaction to a transaction group. Once the transaction has
528 * been assigned, you can modify buffers which belong to held objects as
529 * part of this transaction. You can't modify buffers before the
530 * transaction has been assigned; you can't modify buffers which don't
531 * belong to objects which this transaction holds; you can't hold
532 * objects once the transaction has been assigned. You may hold an
533 * object which you are going to free (with dmu_object_free()), but you
534 * don't have to.
535 *
536 * You can abort the transaction before it has been assigned.
537 *
538 * Note that you may hold buffers (with dmu_buf_hold) at any time,
539 * regardless of transaction state.
540 */
541
542 #define DMU_NEW_OBJECT (-1ULL)
543 #define DMU_OBJECT_END (-1ULL)
544
545 dmu_tx_t *dmu_tx_create(objset_t *os);
546 void dmu_tx_hold_write(dmu_tx_t *tx, uint64_t object, uint64_t off, int len);
547 void dmu_tx_hold_free(dmu_tx_t *tx, uint64_t object, uint64_t off,
548 uint64_t len);
549 void dmu_tx_hold_zap(dmu_tx_t *tx, uint64_t object, int add, const char *name);
550 void dmu_tx_hold_bonus(dmu_tx_t *tx, uint64_t object);
551 void dmu_tx_hold_spill(dmu_tx_t *tx, uint64_t object);
552 void dmu_tx_hold_sa(dmu_tx_t *tx, struct sa_handle *hdl, boolean_t may_grow);
553 void dmu_tx_hold_sa_create(dmu_tx_t *tx, int total_size);
554 void dmu_tx_abort(dmu_tx_t *tx);
555 int dmu_tx_assign(dmu_tx_t *tx, enum txg_how txg_how);
556 void dmu_tx_wait(dmu_tx_t *tx);
557 void dmu_tx_commit(dmu_tx_t *tx);
558
559 /*
560 * To register a commit callback, dmu_tx_callback_register() must be called.
561 *
562 * dcb_data is a pointer to caller private data that is passed on as a
563 * callback parameter. The caller is responsible for properly allocating and
564 * freeing it.
565 *
566 * When registering a callback, the transaction must be already created, but
567 * it cannot be committed or aborted. It can be assigned to a txg or not.
568 *
569 * The callback will be called after the transaction has been safely written
570 * to stable storage and will also be called if the dmu_tx is aborted.
571 * If there is any error which prevents the transaction from being committed to
572 * disk, the callback will be called with a value of error != 0.
573 */
574 typedef void dmu_tx_callback_func_t(void *dcb_data, int error);
575
576 void dmu_tx_callback_register(dmu_tx_t *tx, dmu_tx_callback_func_t *dcb_func,
577 void *dcb_data);
578
579 /*
580 * Free up the data blocks for a defined range of a file. If size is
581 * -1, the range from offset to end-of-file is freed.
582 */
583 int dmu_free_range(objset_t *os, uint64_t object, uint64_t offset,
584 uint64_t size, dmu_tx_t *tx);
585 int dmu_free_long_range(objset_t *os, uint64_t object, uint64_t offset,
586 uint64_t size);
587 int dmu_free_long_object(objset_t *os, uint64_t object);
588
589 /*
590 * Convenience functions.
591 *
592 * Canfail routines will return 0 on success, or an errno if there is a
593 * nonrecoverable I/O error.
594 */
595 #define DMU_READ_PREFETCH 0 /* prefetch */
596 #define DMU_READ_NO_PREFETCH 1 /* don't prefetch */
597 int dmu_read(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
598 void *buf, uint32_t flags);
599 void dmu_write(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
600 const void *buf, dmu_tx_t *tx);
601 void dmu_prealloc(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
602 dmu_tx_t *tx);
603 int dmu_read_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size);
604 int dmu_write_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size,
605 dmu_tx_t *tx);
606 int dmu_write_uio_dbuf(dmu_buf_t *zdb, struct uio *uio, uint64_t size,
607 dmu_tx_t *tx);
608 int dmu_write_pages(objset_t *os, uint64_t object, uint64_t offset,
609 uint64_t size, struct page *pp, dmu_tx_t *tx);
610 struct arc_buf *dmu_request_arcbuf(dmu_buf_t *handle, int size);
611 void dmu_return_arcbuf(struct arc_buf *buf);
612 void dmu_assign_arcbuf(dmu_buf_t *handle, uint64_t offset, struct arc_buf *buf,
613 dmu_tx_t *tx);
614 int dmu_xuio_init(struct xuio *uio, int niov);
615 void dmu_xuio_fini(struct xuio *uio);
616 int dmu_xuio_add(struct xuio *uio, struct arc_buf *abuf, offset_t off,
617 size_t n);
618 int dmu_xuio_cnt(struct xuio *uio);
619 struct arc_buf *dmu_xuio_arcbuf(struct xuio *uio, int i);
620 void dmu_xuio_clear(struct xuio *uio, int i);
621 void xuio_stat_wbuf_copied();
622 void xuio_stat_wbuf_nocopy();
623
624 extern int zfs_prefetch_disable;
625
626 /*
627 * Asynchronously try to read in the data.
628 */
629 void dmu_prefetch(objset_t *os, uint64_t object, uint64_t offset,
630 uint64_t len);
631
632 typedef struct dmu_object_info {
633 /* All sizes are in bytes unless otherwise indicated. */
634 uint32_t doi_data_block_size;
635 uint32_t doi_metadata_block_size;
636 dmu_object_type_t doi_type;
637 dmu_object_type_t doi_bonus_type;
638 uint64_t doi_bonus_size;
639 uint8_t doi_indirection; /* 2 = dnode->indirect->data */
640 uint8_t doi_checksum;
641 uint8_t doi_compress;
642 uint8_t doi_pad[5];
643 uint64_t doi_physical_blocks_512; /* data + metadata, 512b blks */
644 uint64_t doi_max_offset;
645 uint64_t doi_fill_count; /* number of non-empty blocks */
646 } dmu_object_info_t;
647
648 typedef void arc_byteswap_func_t(void *buf, size_t size);
649
650 typedef struct dmu_object_type_info {
651 dmu_object_byteswap_t ot_byteswap;
652 boolean_t ot_metadata;
653 char *ot_name;
654 } dmu_object_type_info_t;
655
656 typedef struct dmu_object_byteswap_info {
657 arc_byteswap_func_t *ob_func;
658 char *ob_name;
659 } dmu_object_byteswap_info_t;
660
661 extern const dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES];
662 extern const dmu_object_byteswap_info_t dmu_ot_byteswap[DMU_BSWAP_NUMFUNCS];
663
664 /*
665 * Get information on a DMU object.
666 *
667 * Return 0 on success or ENOENT if object is not allocated.
668 *
669 * If doi is NULL, just indicates whether the object exists.
670 */
671 int dmu_object_info(objset_t *os, uint64_t object, dmu_object_info_t *doi);
672 /* Like dmu_object_info, but faster if you have a held dnode in hand. */
673 void dmu_object_info_from_dnode(struct dnode *dn, dmu_object_info_t *doi);
674 /* Like dmu_object_info, but faster if you have a held dbuf in hand. */
675 void dmu_object_info_from_db(dmu_buf_t *db, dmu_object_info_t *doi);
676 /*
677 * Like dmu_object_info_from_db, but faster still when you only care about
678 * the size. This is specifically optimized for zfs_getattr().
679 */
680 void dmu_object_size_from_db(dmu_buf_t *db, uint32_t *blksize,
681 u_longlong_t *nblk512);
682
683 typedef struct dmu_objset_stats {
684 uint64_t dds_num_clones; /* number of clones of this */
685 uint64_t dds_creation_txg;
686 uint64_t dds_guid;
687 dmu_objset_type_t dds_type;
688 uint8_t dds_is_snapshot;
689 uint8_t dds_inconsistent;
690 char dds_origin[MAXNAMELEN];
691 } dmu_objset_stats_t;
692
693 /*
694 * Get stats on a dataset.
695 */
696 void dmu_objset_fast_stat(objset_t *os, dmu_objset_stats_t *stat);
697
698 /*
699 * Add entries to the nvlist for all the objset's properties. See
700 * zfs_prop_table[] and zfs(1m) for details on the properties.
701 */
702 void dmu_objset_stats(objset_t *os, struct nvlist *nv);
703
704 /*
705 * Get the space usage statistics for statvfs().
706 *
707 * refdbytes is the amount of space "referenced" by this objset.
708 * availbytes is the amount of space available to this objset, taking
709 * into account quotas & reservations, assuming that no other objsets
710 * use the space first. These values correspond to the 'referenced' and
711 * 'available' properties, described in the zfs(1m) manpage.
712 *
713 * usedobjs and availobjs are the number of objects currently allocated,
714 * and available.
715 */
716 void dmu_objset_space(objset_t *os, uint64_t *refdbytesp, uint64_t *availbytesp,
717 uint64_t *usedobjsp, uint64_t *availobjsp);
718
719 /*
720 * The fsid_guid is a 56-bit ID that can change to avoid collisions.
721 * (Contrast with the ds_guid which is a 64-bit ID that will never
722 * change, so there is a small probability that it will collide.)
723 */
724 uint64_t dmu_objset_fsid_guid(objset_t *os);
725
726 /*
727 * Get the [cm]time for an objset's snapshot dir
728 */
729 timestruc_t dmu_objset_snap_cmtime(objset_t *os);
730
731 int dmu_objset_is_snapshot(objset_t *os);
732
733 extern struct spa *dmu_objset_spa(objset_t *os);
734 extern struct zilog *dmu_objset_zil(objset_t *os);
735 extern struct dsl_pool *dmu_objset_pool(objset_t *os);
736 extern struct dsl_dataset *dmu_objset_ds(objset_t *os);
737 extern void dmu_objset_name(objset_t *os, char *buf);
738 extern dmu_objset_type_t dmu_objset_type(objset_t *os);
739 extern uint64_t dmu_objset_id(objset_t *os);
740 extern uint64_t dmu_objset_syncprop(objset_t *os);
741 extern uint64_t dmu_objset_logbias(objset_t *os);
742 extern int dmu_snapshot_list_next(objset_t *os, int namelen, char *name,
743 uint64_t *id, uint64_t *offp, boolean_t *case_conflict);
744 extern int dmu_snapshot_realname(objset_t *os, char *name, char *real,
745 int maxlen, boolean_t *conflict);
746 extern int dmu_dir_list_next(objset_t *os, int namelen, char *name,
747 uint64_t *idp, uint64_t *offp);
748
749 typedef int objset_used_cb_t(dmu_object_type_t bonustype,
750 void *bonus, uint64_t *userp, uint64_t *groupp);
751 extern void dmu_objset_register_type(dmu_objset_type_t ost,
752 objset_used_cb_t *cb);
753 extern void dmu_objset_set_user(objset_t *os, void *user_ptr);
754 extern void *dmu_objset_get_user(objset_t *os);
755
756 /*
757 * Return the txg number for the given assigned transaction.
758 */
759 uint64_t dmu_tx_get_txg(dmu_tx_t *tx);
760
761 /*
762 * Synchronous write.
763 * If a parent zio is provided this function initiates a write on the
764 * provided buffer as a child of the parent zio.
765 * In the absence of a parent zio, the write is completed synchronously.
766 * At write completion, blk is filled with the bp of the written block.
767 * Note that while the data covered by this function will be on stable
768 * storage when the write completes this new data does not become a
769 * permanent part of the file until the associated transaction commits.
770 */
771
772 /*
773 * {zfs,zvol,ztest}_get_done() args
774 */
775 typedef struct zgd {
776 struct zilog *zgd_zilog;
777 struct blkptr *zgd_bp;
778 dmu_buf_t *zgd_db;
779 struct rl *zgd_rl;
780 void *zgd_private;
781 } zgd_t;
782
783 typedef void dmu_sync_cb_t(zgd_t *arg, int error);
784 int dmu_sync(struct zio *zio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd);
785
786 /*
787 * Find the next hole or data block in file starting at *off
788 * Return found offset in *off. Return ESRCH for end of file.
789 */
790 int dmu_offset_next(objset_t *os, uint64_t object, boolean_t hole,
791 uint64_t *off);
792
793 /*
794 * Initial setup and final teardown.
795 */
796 extern void dmu_init(void);
797 extern void dmu_fini(void);
798
799 typedef void (*dmu_traverse_cb_t)(objset_t *os, void *arg, struct blkptr *bp,
800 uint64_t object, uint64_t offset, int len);
801 void dmu_traverse_objset(objset_t *os, uint64_t txg_start,
802 dmu_traverse_cb_t cb, void *arg);
803
804 int dmu_diff(const char *tosnap_name, const char *fromsnap_name,
805 struct vnode *vp, offset_t *offp);
806
807 /* CRC64 table */
808 #define ZFS_CRC64_POLY 0xC96C5795D7870F42ULL /* ECMA-182, reflected form */
809 extern uint64_t zfs_crc64_table[256];
810
811 #ifdef __cplusplus
812 }
813 #endif
814
815 #endif /* _SYS_DMU_H */