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) 2012 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/zfs_context.h>
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_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 /*
286 * The names of zap entries in the DIRECTORY_OBJECT of the MOS.
287 */
288 #define DMU_POOL_DIRECTORY_OBJECT 1
289 #define DMU_POOL_CONFIG "config"
290 #define DMU_POOL_FEATURES_FOR_WRITE "features_for_write"
291 #define DMU_POOL_FEATURES_FOR_READ "features_for_read"
292 #define DMU_POOL_FEATURE_DESCRIPTIONS "feature_descriptions"
293 #define DMU_POOL_ROOT_DATASET "root_dataset"
294 #define DMU_POOL_SYNC_BPOBJ "sync_bplist"
295 #define DMU_POOL_ERRLOG_SCRUB "errlog_scrub"
296 #define DMU_POOL_ERRLOG_LAST "errlog_last"
297 #define DMU_POOL_SPARES "spares"
298 #define DMU_POOL_DEFLATE "deflate"
299 #define DMU_POOL_HISTORY "history"
300 #define DMU_POOL_PROPS "pool_props"
301 #define DMU_POOL_L2CACHE "l2cache"
302 #define DMU_POOL_TMP_USERREFS "tmp_userrefs"
303 #define DMU_POOL_DDT "DDT-%s-%s-%s"
304 #define DMU_POOL_DDT_STATS "DDT-statistics"
305 #define DMU_POOL_CREATION_VERSION "creation_version"
306 #define DMU_POOL_SCAN "scan"
307 #define DMU_POOL_FREE_BPOBJ "free_bpobj"
308 #define DMU_POOL_BPTREE_OBJ "bptree_obj"
309 #define DMU_POOL_EMPTY_BPOBJ "empty_bpobj"
310
311 /*
312 * Allocate an object from this objset. The range of object numbers
313 * available is (0, DN_MAX_OBJECT). Object 0 is the meta-dnode.
314 *
315 * The transaction must be assigned to a txg. The newly allocated
316 * object will be "held" in the transaction (ie. you can modify the
317 * newly allocated object in this transaction).
318 *
319 * dmu_object_alloc() chooses an object and returns it in *objectp.
320 *
321 * dmu_object_claim() allocates a specific object number. If that
322 * number is already allocated, it fails and returns EEXIST.
323 *
324 * Return 0 on success, or ENOSPC or EEXIST as specified above.
325 */
326 uint64_t dmu_object_alloc(objset_t *os, dmu_object_type_t ot,
327 int blocksize, dmu_object_type_t bonus_type, int bonus_len, dmu_tx_t *tx);
328 int dmu_object_claim(objset_t *os, uint64_t object, 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_reclaim(objset_t *os, uint64_t object, dmu_object_type_t ot,
331 int blocksize, dmu_object_type_t bonustype, int bonuslen);
332
333 /*
334 * Free an object from this objset.
335 *
336 * The object's data will be freed as well (ie. you don't need to call
337 * dmu_free(object, 0, -1, tx)).
338 *
339 * The object need not be held in the transaction.
340 *
341 * If there are any holds on this object's buffers (via dmu_buf_hold()),
342 * or tx holds on the object (via dmu_tx_hold_object()), you can not
343 * free it; it fails and returns EBUSY.
344 *
345 * If the object is not allocated, it fails and returns ENOENT.
346 *
347 * Return 0 on success, or EBUSY or ENOENT as specified above.
348 */
349 int dmu_object_free(objset_t *os, uint64_t object, dmu_tx_t *tx);
350
351 /*
352 * Find the next allocated or free object.
353 *
354 * The objectp parameter is in-out. It will be updated to be the next
355 * object which is allocated. Ignore objects which have not been
356 * modified since txg.
357 *
358 * XXX Can only be called on a objset with no dirty data.
359 *
360 * Returns 0 on success, or ENOENT if there are no more objects.
361 */
362 int dmu_object_next(objset_t *os, uint64_t *objectp,
363 boolean_t hole, uint64_t txg);
364
365 /*
366 * Set the data blocksize for an object.
367 *
368 * The object cannot have any blocks allcated beyond the first. If
369 * the first block is allocated already, the new size must be greater
370 * than the current block size. If these conditions are not met,
371 * ENOTSUP will be returned.
372 *
373 * Returns 0 on success, or EBUSY if there are any holds on the object
374 * contents, or ENOTSUP as described above.
375 */
376 int dmu_object_set_blocksize(objset_t *os, uint64_t object, uint64_t size,
377 int ibs, dmu_tx_t *tx);
378
379 /*
380 * Set the checksum property on a dnode. The new checksum algorithm will
381 * apply to all newly written blocks; existing blocks will not be affected.
382 */
383 void dmu_object_set_checksum(objset_t *os, uint64_t object, uint8_t checksum,
384 dmu_tx_t *tx);
385
386 /*
387 * Set the compress property on a dnode. The new compression algorithm will
388 * apply to all newly written blocks; existing blocks will not be affected.
389 */
390 void dmu_object_set_compress(objset_t *os, uint64_t object, uint8_t compress,
391 dmu_tx_t *tx);
392
393 /*
394 * Decide how to write a block: checksum, compression, number of copies, etc.
395 */
396 #define WP_NOFILL 0x1
397 #define WP_DMU_SYNC 0x2
398 #define WP_SPILL 0x4
399
400 void dmu_write_policy(objset_t *os, struct dnode *dn, int level, int wp,
401 struct zio_prop *zp);
402 /*
403 * The bonus data is accessed more or less like a regular buffer.
404 * You must dmu_bonus_hold() to get the buffer, which will give you a
405 * dmu_buf_t with db_offset==-1ULL, and db_size = the size of the bonus
406 * data. As with any normal buffer, you must call dmu_buf_read() to
407 * read db_data, dmu_buf_will_dirty() before modifying it, and the
408 * object must be held in an assigned transaction before calling
409 * dmu_buf_will_dirty. You may use dmu_buf_set_user() on the bonus
410 * buffer as well. You must release your hold with dmu_buf_rele().
411 */
412 int dmu_bonus_hold(objset_t *os, uint64_t object, void *tag, dmu_buf_t **);
413 int dmu_bonus_max(void);
414 int dmu_set_bonus(dmu_buf_t *, int, dmu_tx_t *);
415 int dmu_set_bonustype(dmu_buf_t *, dmu_object_type_t, dmu_tx_t *);
416 dmu_object_type_t dmu_get_bonustype(dmu_buf_t *);
417 int dmu_rm_spill(objset_t *, uint64_t, dmu_tx_t *);
418
419 /*
420 * Special spill buffer support used by "SA" framework
421 */
422
423 int dmu_spill_hold_by_bonus(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp);
424 int dmu_spill_hold_by_dnode(struct dnode *dn, uint32_t flags,
425 void *tag, dmu_buf_t **dbp);
426 int dmu_spill_hold_existing(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp);
427
428 /*
429 * Obtain the DMU buffer from the specified object which contains the
430 * specified offset. dmu_buf_hold() puts a "hold" on the buffer, so
431 * that it will remain in memory. You must release the hold with
432 * dmu_buf_rele(). You musn't access the dmu_buf_t after releasing your
433 * hold. You must have a hold on any dmu_buf_t* you pass to the DMU.
434 *
435 * You must call dmu_buf_read, dmu_buf_will_dirty, or dmu_buf_will_fill
436 * on the returned buffer before reading or writing the buffer's
437 * db_data. The comments for those routines describe what particular
438 * operations are valid after calling them.
439 *
440 * The object number must be a valid, allocated object number.
441 */
442 int dmu_buf_hold(objset_t *os, uint64_t object, uint64_t offset,
443 void *tag, dmu_buf_t **, int flags);
444 void dmu_buf_add_ref(dmu_buf_t *db, void* tag);
445 void dmu_buf_rele(dmu_buf_t *db, void *tag);
446 uint64_t dmu_buf_refcount(dmu_buf_t *db);
447
448 /*
449 * dmu_buf_hold_array holds the DMU buffers which contain all bytes in a
450 * range of an object. A pointer to an array of dmu_buf_t*'s is
451 * returned (in *dbpp).
452 *
453 * dmu_buf_rele_array releases the hold on an array of dmu_buf_t*'s, and
454 * frees the array. The hold on the array of buffers MUST be released
455 * with dmu_buf_rele_array. You can NOT release the hold on each buffer
456 * individually with dmu_buf_rele.
457 */
458 int dmu_buf_hold_array_by_bonus(dmu_buf_t *db, uint64_t offset,
459 uint64_t length, int read, void *tag, int *numbufsp, dmu_buf_t ***dbpp);
460 void dmu_buf_rele_array(dmu_buf_t **, int numbufs, void *tag);
461
462 struct dmu_buf_user;
463
464 typedef void dmu_buf_evict_func_t(struct dmu_buf_user *);
465
466 /*
467 * The DMU buffer user object is used to allow private data to be
468 * associated with a dbuf for the duration of its lifetime. This private
469 * data must include a dmu_buf_user_t as its first object, which is passed
470 * into the DMU user data API and can be attached to a dbuf. Clients can
471 * regain access to their private data structure with a cast.
472 *
473 * DMU buffer users can be notified via a callback when their associated
474 * dbuf has been evicted. This is typically used to free the user's
475 * private data. The eviction callback is executed without the dbuf
476 * mutex held or any other type of mechanism to guarantee that the
477 * dbuf is still available. For this reason, users must assume the dbuf
478 * has already been freed and not reference the dbuf from the callback
479 * context.
480 *
481 * Users requestion "immediate eviction" are notified as soon as the dbuf
482 * is only referenced by dirty records (dirties == holds). Otherwise the
483 * eviction callback occurs after the last reference to the dbuf is dropped.
484 *
485 * Eviction Callback Processing
486 * ============================
487 * In any context where a dbuf reference drop may trigger an eviction, an
488 * eviction queue object must be provided. This queue must then be
489 * processed while not holding any dbuf locks. In this way, the user can
490 * perform any work needed in their eviction function without fear of
491 * lock order reversals.
492 *
493 * Implementation Note
494 * ============================
495 * Some users will occasionally want to map a structure directly onto the
496 * backing dbuf. Using an union with an name alias macro to access these
497 * overlays reduces the ugliness of code that accesses them. Initial work on
498 * user objects involved using a macro that took the user object as an
499 * argument to access the fields, which resulted in hundreds of lines of
500 * needless diffs and wasn't any easier to read.
501 */
502 typedef struct dmu_buf_user {
503 /*
504 * This instance's link in the eviction queue. Set when the buffer
505 * has evicted and the callback needs to be called.
506 */
507 list_node_t evict_queue_link;
508 /** This instance's eviction function pointer. */
509 dmu_buf_evict_func_t *evict_func;
510 } dmu_buf_user_t;
511
512 /*
513 * Initialize the given dmu_buf_user_t instance with the eviction function
514 * evict_func, to be called when the user is evicted.
515 *
516 * NOTE: This function should only be called once on a given object. To
517 * help enforce this, dbu should already be zeroed on entry.
518 */
519 static inline void
520 dmu_buf_init_user(dmu_buf_user_t *dbu, dmu_buf_evict_func_t *evict_func)
521 {
522 ASSERT(dbu->evict_func == NULL);
523 ASSERT(!list_link_active(&dbu->evict_queue_link));
524 dbu->evict_func = evict_func;
525 }
526
527 static inline void
528 dmu_buf_create_user_evict_list(list_t *evict_list_p)
529 {
530 list_create(evict_list_p, sizeof(dmu_buf_user_t),
531 offsetof(dmu_buf_user_t, evict_queue_link));
532 }
533
534 static inline void
535 dmu_buf_process_user_evicts(list_t *evict_list_p)
536 {
537 dmu_buf_user_t *dbu, *next;
538
539 for (dbu = (dmu_buf_user_t *)list_head(evict_list_p); dbu != NULL;
540 dbu = next) {
541 next = (dmu_buf_user_t *)list_next(evict_list_p, dbu);
542 list_remove(evict_list_p, dbu);
543 dbu->evict_func(dbu);
544 }
545 }
546
547 static inline void
548 dmu_buf_destroy_user_evict_list(list_t *evict_list_p)
549 {
550 dmu_buf_process_user_evicts(evict_list_p);
551 list_destroy(evict_list_p);
552 }
553
554 dmu_buf_user_t *dmu_buf_set_user(dmu_buf_t *db, dmu_buf_user_t *user);
555 dmu_buf_user_t *dmu_buf_set_user_ie(dmu_buf_t *db, dmu_buf_user_t *user);
556 dmu_buf_user_t *dmu_buf_replace_user(dmu_buf_t *db,
557 dmu_buf_user_t *old_user, dmu_buf_user_t *new_user);
558 dmu_buf_user_t *dmu_buf_remove_user(dmu_buf_t *db, dmu_buf_user_t *user);
559 dmu_buf_user_t *dmu_buf_get_user(dmu_buf_t *db);
560
561 /*
562 * Returns the blkptr associated with this dbuf, or NULL if not set.
563 */
564 struct blkptr *dmu_buf_get_blkptr(dmu_buf_t *db);
565
566 /*
567 * Indicate that you are going to modify the buffer's data (db_data).
568 *
569 * The transaction (tx) must be assigned to a txg (ie. you've called
570 * dmu_tx_assign()). The buffer's object must be held in the tx
571 * (ie. you've called dmu_tx_hold_object(tx, db->db_object)).
572 */
573 void dmu_buf_will_dirty(dmu_buf_t *db, dmu_tx_t *tx);
574
575 /*
576 * Tells if the given dbuf is freeable.
577 */
578 boolean_t dmu_buf_freeable(dmu_buf_t *);
579
580 /*
581 * You must create a transaction, then hold the objects which you will
582 * (or might) modify as part of this transaction. Then you must assign
583 * the transaction to a transaction group. Once the transaction has
584 * been assigned, you can modify buffers which belong to held objects as
585 * part of this transaction. You can't modify buffers before the
586 * transaction has been assigned; you can't modify buffers which don't
587 * belong to objects which this transaction holds; you can't hold
588 * objects once the transaction has been assigned. You may hold an
589 * object which you are going to free (with dmu_object_free()), but you
590 * don't have to.
591 *
592 * You can abort the transaction before it has been assigned.
593 *
594 * Note that you may hold buffers (with dmu_buf_hold) at any time,
595 * regardless of transaction state.
596 */
597
598 #define DMU_NEW_OBJECT (-1ULL)
599 #define DMU_OBJECT_END (-1ULL)
600
601 dmu_tx_t *dmu_tx_create(objset_t *os);
602 void dmu_tx_hold_write(dmu_tx_t *tx, uint64_t object, uint64_t off, int len);
603 void dmu_tx_hold_free(dmu_tx_t *tx, uint64_t object, uint64_t off,
604 uint64_t len);
605 void dmu_tx_hold_zap(dmu_tx_t *tx, uint64_t object, int add, const char *name);
606 void dmu_tx_hold_bonus(dmu_tx_t *tx, uint64_t object);
607 void dmu_tx_hold_spill(dmu_tx_t *tx, uint64_t object);
608 void dmu_tx_hold_sa(dmu_tx_t *tx, struct sa_handle *hdl, boolean_t may_grow);
609 void dmu_tx_hold_sa_create(dmu_tx_t *tx, int total_size);
610 void dmu_tx_abort(dmu_tx_t *tx);
611 int dmu_tx_assign(dmu_tx_t *tx, enum txg_how txg_how);
612 void dmu_tx_wait(dmu_tx_t *tx);
613 void dmu_tx_commit(dmu_tx_t *tx);
614
615 /*
616 * To register a commit callback, dmu_tx_callback_register() must be called.
617 *
618 * dcb_data is a pointer to caller private data that is passed on as a
619 * callback parameter. The caller is responsible for properly allocating and
620 * freeing it.
621 *
622 * When registering a callback, the transaction must be already created, but
623 * it cannot be committed or aborted. It can be assigned to a txg or not.
624 *
625 * The callback will be called after the transaction has been safely written
626 * to stable storage and will also be called if the dmu_tx is aborted.
627 * If there is any error which prevents the transaction from being committed to
628 * disk, the callback will be called with a value of error != 0.
629 */
630 typedef void dmu_tx_callback_func_t(void *dcb_data, int error);
631
632 void dmu_tx_callback_register(dmu_tx_t *tx, dmu_tx_callback_func_t *dcb_func,
633 void *dcb_data);
634
635 /*
636 * Free up the data blocks for a defined range of a file. If size is
637 * -1, the range from offset to end-of-file is freed.
638 */
639 int dmu_free_range(objset_t *os, uint64_t object, uint64_t offset,
640 uint64_t size, dmu_tx_t *tx);
641 int dmu_free_long_range(objset_t *os, uint64_t object, uint64_t offset,
642 uint64_t size);
643 int dmu_free_object(objset_t *os, uint64_t object);
644
645 /*
646 * Convenience functions.
647 *
648 * Canfail routines will return 0 on success, or an errno if there is a
649 * nonrecoverable I/O error.
650 */
651 #define DMU_READ_PREFETCH 0 /* prefetch */
652 #define DMU_READ_NO_PREFETCH 1 /* don't prefetch */
653 int dmu_read(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
654 void *buf, uint32_t flags);
655 void dmu_write(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
656 const void *buf, dmu_tx_t *tx);
657 void dmu_prealloc(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
658 dmu_tx_t *tx);
659 int dmu_read_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size);
660 int dmu_write_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size,
661 dmu_tx_t *tx);
662 int dmu_write_uio_dbuf(dmu_buf_t *zdb, struct uio *uio, uint64_t size,
663 dmu_tx_t *tx);
664 int dmu_write_pages(objset_t *os, uint64_t object, uint64_t offset,
665 uint64_t size, struct page *pp, dmu_tx_t *tx);
666 struct arc_buf *dmu_request_arcbuf(dmu_buf_t *handle, int size);
667 void dmu_return_arcbuf(struct arc_buf *buf);
668 void dmu_assign_arcbuf(dmu_buf_t *handle, uint64_t offset, struct arc_buf *buf,
669 dmu_tx_t *tx);
670 int dmu_xuio_init(struct xuio *uio, int niov);
671 void dmu_xuio_fini(struct xuio *uio);
672 int dmu_xuio_add(struct xuio *uio, struct arc_buf *abuf, offset_t off,
673 size_t n);
674 int dmu_xuio_cnt(struct xuio *uio);
675 struct arc_buf *dmu_xuio_arcbuf(struct xuio *uio, int i);
676 void dmu_xuio_clear(struct xuio *uio, int i);
677 void xuio_stat_wbuf_copied();
678 void xuio_stat_wbuf_nocopy();
679
680 extern int zfs_prefetch_disable;
681
682 /*
683 * Asynchronously try to read in the data.
684 */
685 void dmu_prefetch(objset_t *os, uint64_t object, uint64_t offset,
686 uint64_t len);
687
688 typedef struct dmu_object_info {
689 /* All sizes are in bytes unless otherwise indicated. */
690 uint32_t doi_data_block_size;
691 uint32_t doi_metadata_block_size;
692 dmu_object_type_t doi_type;
693 dmu_object_type_t doi_bonus_type;
694 uint64_t doi_bonus_size;
695 uint8_t doi_indirection; /* 2 = dnode->indirect->data */
696 uint8_t doi_checksum;
697 uint8_t doi_compress;
698 uint8_t doi_pad[5];
699 uint64_t doi_physical_blocks_512; /* data + metadata, 512b blks */
700 uint64_t doi_max_offset;
701 uint64_t doi_fill_count; /* number of non-empty blocks */
702 } dmu_object_info_t;
703
704 typedef void arc_byteswap_func_t(void *buf, size_t size);
705
706 typedef struct dmu_object_type_info {
707 dmu_object_byteswap_t ot_byteswap;
708 boolean_t ot_metadata;
709 char *ot_name;
710 } dmu_object_type_info_t;
711
712 typedef struct dmu_object_byteswap_info {
713 arc_byteswap_func_t *ob_func;
714 char *ob_name;
715 } dmu_object_byteswap_info_t;
716
717 extern const dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES];
718 extern const dmu_object_byteswap_info_t dmu_ot_byteswap[DMU_BSWAP_NUMFUNCS];
719
720 /*
721 * Get information on a DMU object.
722 *
723 * Return 0 on success or ENOENT if object is not allocated.
724 *
725 * If doi is NULL, just indicates whether the object exists.
726 */
727 int dmu_object_info(objset_t *os, uint64_t object, dmu_object_info_t *doi);
728 void dmu_object_info_from_dnode(struct dnode *dn, dmu_object_info_t *doi);
729 void dmu_object_info_from_db(dmu_buf_t *db, dmu_object_info_t *doi);
730 void dmu_object_size_from_db(dmu_buf_t *db, uint32_t *blksize,
731 u_longlong_t *nblk512);
732
733 typedef struct dmu_objset_stats {
734 uint64_t dds_num_clones; /* number of clones of this */
735 uint64_t dds_creation_txg;
736 uint64_t dds_guid;
737 dmu_objset_type_t dds_type;
738 uint8_t dds_is_snapshot;
739 uint8_t dds_inconsistent;
740 char dds_origin[MAXNAMELEN];
741 } dmu_objset_stats_t;
742
743 /*
744 * Get stats on a dataset.
745 */
746 void dmu_objset_fast_stat(objset_t *os, dmu_objset_stats_t *stat);
747
748 /*
749 * Add entries to the nvlist for all the objset's properties. See
750 * zfs_prop_table[] and zfs(1m) for details on the properties.
751 */
752 void dmu_objset_stats(objset_t *os, struct nvlist *nv);
753
754 /*
755 * Get the space usage statistics for statvfs().
756 *
757 * refdbytes is the amount of space "referenced" by this objset.
758 * availbytes is the amount of space available to this objset, taking
759 * into account quotas & reservations, assuming that no other objsets
760 * use the space first. These values correspond to the 'referenced' and
761 * 'available' properties, described in the zfs(1m) manpage.
762 *
763 * usedobjs and availobjs are the number of objects currently allocated,
764 * and available.
765 */
766 void dmu_objset_space(objset_t *os, uint64_t *refdbytesp, uint64_t *availbytesp,
767 uint64_t *usedobjsp, uint64_t *availobjsp);
768
769 /*
770 * The fsid_guid is a 56-bit ID that can change to avoid collisions.
771 * (Contrast with the ds_guid which is a 64-bit ID that will never
772 * change, so there is a small probability that it will collide.)
773 */
774 uint64_t dmu_objset_fsid_guid(objset_t *os);
775
776 /*
777 * Get the [cm]time for an objset's snapshot dir
778 */
779 timestruc_t dmu_objset_snap_cmtime(objset_t *os);
780
781 int dmu_objset_is_snapshot(objset_t *os);
782
783 extern struct spa *dmu_objset_spa(objset_t *os);
784 extern struct zilog *dmu_objset_zil(objset_t *os);
785 extern struct dsl_pool *dmu_objset_pool(objset_t *os);
786 extern struct dsl_dataset *dmu_objset_ds(objset_t *os);
787 extern void dmu_objset_name(objset_t *os, char *buf);
788 extern dmu_objset_type_t dmu_objset_type(objset_t *os);
789 extern uint64_t dmu_objset_id(objset_t *os);
790 extern uint64_t dmu_objset_syncprop(objset_t *os);
791 extern uint64_t dmu_objset_logbias(objset_t *os);
792 extern int dmu_snapshot_list_next(objset_t *os, int namelen, char *name,
793 uint64_t *id, uint64_t *offp, boolean_t *case_conflict);
794 extern int dmu_snapshot_realname(objset_t *os, char *name, char *real,
795 int maxlen, boolean_t *conflict);
796 extern int dmu_dir_list_next(objset_t *os, int namelen, char *name,
797 uint64_t *idp, uint64_t *offp);
798
799 typedef int objset_used_cb_t(dmu_object_type_t bonustype,
800 void *bonus, uint64_t *userp, uint64_t *groupp);
801 extern void dmu_objset_register_type(dmu_objset_type_t ost,
802 objset_used_cb_t *cb);
803 extern void dmu_objset_set_user(objset_t *os, void *user_ptr);
804 extern void *dmu_objset_get_user(objset_t *os);
805
806 /*
807 * Return the txg number for the given assigned transaction.
808 */
809 uint64_t dmu_tx_get_txg(dmu_tx_t *tx);
810
811 /*
812 * Synchronous write.
813 * If a parent zio is provided this function initiates a write on the
814 * provided buffer as a child of the parent zio.
815 * In the absence of a parent zio, the write is completed synchronously.
816 * At write completion, blk is filled with the bp of the written block.
817 * Note that while the data covered by this function will be on stable
818 * storage when the write completes this new data does not become a
819 * permanent part of the file until the associated transaction commits.
820 */
821
822 /*
823 * {zfs,zvol,ztest}_get_done() args
824 */
825 typedef struct zgd {
826 struct zilog *zgd_zilog;
827 struct blkptr *zgd_bp;
828 dmu_buf_t *zgd_db;
829 struct rl *zgd_rl;
830 void *zgd_private;
831 } zgd_t;
832
833 typedef void dmu_sync_cb_t(zgd_t *arg, int error);
834 int dmu_sync(struct zio *zio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd);
835
836 /*
837 * Find the next hole or data block in file starting at *off
838 * Return found offset in *off. Return ESRCH for end of file.
839 */
840 int dmu_offset_next(objset_t *os, uint64_t object, boolean_t hole,
841 uint64_t *off);
842
843 /*
844 * Initial setup and final teardown.
845 */
846 extern void dmu_init(void);
847 extern void dmu_fini(void);
848
849 typedef void (*dmu_traverse_cb_t)(objset_t *os, void *arg, struct blkptr *bp,
850 uint64_t object, uint64_t offset, int len);
851 void dmu_traverse_objset(objset_t *os, uint64_t txg_start,
852 dmu_traverse_cb_t cb, void *arg);
853
854 int dmu_diff(const char *tosnap_name, const char *fromsnap_name,
855 struct vnode *vp, offset_t *offp);
856
857 /* CRC64 table */
858 #define ZFS_CRC64_POLY 0xC96C5795D7870F42ULL /* ECMA-182, reflected form */
859 extern uint64_t zfs_crc64_table[256];
860
861 #ifdef __cplusplus
862 }
863 #endif
864
865 #endif /* _SYS_DMU_H */