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) 2011, 2016 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 DEY Storage Systems, Inc.
28 * Copyright 2014 HybridCluster. All rights reserved.
29 * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
30 * Copyright 2013 Saso Kiselkov. All rights reserved.
31 * Copyright (c) 2014 Integros [integros.com]
32 */
33
34 /* Portions Copyright 2010 Robert Milkowski */
35
36 #ifndef _SYS_DMU_H
37 #define _SYS_DMU_H
38
39 /*
40 * This file describes the interface that the DMU provides for its
41 * consumers.
42 *
43 * The DMU also interacts with the SPA. That interface is described in
44 * dmu_spa.h.
45 */
46
47 #include <sys/zfs_context.h>
48 #include <sys/cred.h>
49 #include <sys/fs/zfs.h>
50 #include <sys/zio_priority.h>
51
52 #ifdef __cplusplus
53 extern "C" {
54 #endif
55
56 struct uio;
57 struct xuio;
58 struct page;
59 struct vnode;
60 struct spa;
61 struct zilog;
62 struct zio;
63 struct blkptr;
64 struct zap_cursor;
65 struct dsl_dataset;
66 struct dsl_pool;
67 struct dnode;
68 struct drr_begin;
69 struct drr_end;
70 struct zbookmark_phys;
71 struct spa;
72 struct nvlist;
73 struct arc_buf;
74 struct zio_prop;
75 struct sa_handle;
76 struct file;
77
78 typedef struct objset objset_t;
79 typedef struct dmu_tx dmu_tx_t;
80 typedef struct dsl_dir dsl_dir_t;
81 typedef struct dnode dnode_t;
82
83 typedef enum dmu_object_byteswap {
84 DMU_BSWAP_UINT8,
85 DMU_BSWAP_UINT16,
86 DMU_BSWAP_UINT32,
87 DMU_BSWAP_UINT64,
88 DMU_BSWAP_ZAP,
89 DMU_BSWAP_DNODE,
90 DMU_BSWAP_OBJSET,
91 DMU_BSWAP_ZNODE,
92 DMU_BSWAP_OLDACL,
93 DMU_BSWAP_ACL,
94 /*
95 * Allocating a new byteswap type number makes the on-disk format
96 * incompatible with any other format that uses the same number.
97 *
98 * Data can usually be structured to work with one of the
99 * DMU_BSWAP_UINT* or DMU_BSWAP_ZAP types.
100 */
101 DMU_BSWAP_NUMFUNCS
102 } dmu_object_byteswap_t;
103
104 #define DMU_OT_NEWTYPE 0x80
105 #define DMU_OT_METADATA 0x40
106 #define DMU_OT_BYTESWAP_MASK 0x3f
107
108 /*
109 * Defines a uint8_t object type. Object types specify if the data
110 * in the object is metadata (boolean) and how to byteswap the data
111 * (dmu_object_byteswap_t).
112 */
113 #define DMU_OT(byteswap, metadata) \
114 (DMU_OT_NEWTYPE | \
115 ((metadata) ? DMU_OT_METADATA : 0) | \
116 ((byteswap) & DMU_OT_BYTESWAP_MASK))
117
118 #define DMU_OT_IS_VALID(ot) (((ot) & DMU_OT_NEWTYPE) ? \
119 ((ot) & DMU_OT_BYTESWAP_MASK) < DMU_BSWAP_NUMFUNCS : \
120 (ot) < DMU_OT_NUMTYPES)
121
122 #define DMU_OT_IS_METADATA(ot) (((ot) & DMU_OT_NEWTYPE) ? \
123 ((ot) & DMU_OT_METADATA) : \
124 dmu_ot[(ot)].ot_metadata)
125
126 /*
127 * These object types use bp_fill != 1 for their L0 bp's. Therefore they can't
128 * have their data embedded (i.e. use a BP_IS_EMBEDDED() bp), because bp_fill
129 * is repurposed for embedded BPs.
130 */
131 #define DMU_OT_HAS_FILL(ot) \
132 ((ot) == DMU_OT_DNODE || (ot) == DMU_OT_OBJSET)
133
134 #define DMU_OT_BYTESWAP(ot) (((ot) & DMU_OT_NEWTYPE) ? \
135 ((ot) & DMU_OT_BYTESWAP_MASK) : \
136 dmu_ot[(ot)].ot_byteswap)
137
138 typedef enum dmu_object_type {
139 DMU_OT_NONE,
140 /* general: */
141 DMU_OT_OBJECT_DIRECTORY, /* ZAP */
142 DMU_OT_OBJECT_ARRAY, /* UINT64 */
143 DMU_OT_PACKED_NVLIST, /* UINT8 (XDR by nvlist_pack/unpack) */
144 DMU_OT_PACKED_NVLIST_SIZE, /* UINT64 */
145 DMU_OT_BPOBJ, /* UINT64 */
146 DMU_OT_BPOBJ_HDR, /* UINT64 */
147 /* spa: */
148 DMU_OT_SPACE_MAP_HEADER, /* UINT64 */
149 DMU_OT_SPACE_MAP, /* UINT64 */
150 /* zil: */
151 DMU_OT_INTENT_LOG, /* UINT64 */
152 /* dmu: */
153 DMU_OT_DNODE, /* DNODE */
154 DMU_OT_OBJSET, /* OBJSET */
155 /* dsl: */
156 DMU_OT_DSL_DIR, /* UINT64 */
157 DMU_OT_DSL_DIR_CHILD_MAP, /* ZAP */
158 DMU_OT_DSL_DS_SNAP_MAP, /* ZAP */
159 DMU_OT_DSL_PROPS, /* ZAP */
160 DMU_OT_DSL_DATASET, /* UINT64 */
161 /* zpl: */
162 DMU_OT_ZNODE, /* ZNODE */
163 DMU_OT_OLDACL, /* Old ACL */
164 DMU_OT_PLAIN_FILE_CONTENTS, /* UINT8 */
165 DMU_OT_DIRECTORY_CONTENTS, /* ZAP */
166 DMU_OT_MASTER_NODE, /* ZAP */
167 DMU_OT_UNLINKED_SET, /* ZAP */
168 /* zvol: */
169 DMU_OT_ZVOL, /* UINT8 */
170 DMU_OT_ZVOL_PROP, /* ZAP */
171 /* other; for testing only! */
172 DMU_OT_PLAIN_OTHER, /* UINT8 */
173 DMU_OT_UINT64_OTHER, /* UINT64 */
174 DMU_OT_ZAP_OTHER, /* ZAP */
175 /* new object types: */
176 DMU_OT_ERROR_LOG, /* ZAP */
177 DMU_OT_SPA_HISTORY, /* UINT8 */
178 DMU_OT_SPA_HISTORY_OFFSETS, /* spa_his_phys_t */
179 DMU_OT_POOL_PROPS, /* ZAP */
180 DMU_OT_DSL_PERMS, /* ZAP */
181 DMU_OT_ACL, /* ACL */
182 DMU_OT_SYSACL, /* SYSACL */
183 DMU_OT_FUID, /* FUID table (Packed NVLIST UINT8) */
184 DMU_OT_FUID_SIZE, /* FUID table size UINT64 */
185 DMU_OT_NEXT_CLONES, /* ZAP */
186 DMU_OT_SCAN_QUEUE, /* ZAP */
187 DMU_OT_USERGROUP_USED, /* ZAP */
188 DMU_OT_USERGROUP_QUOTA, /* ZAP */
189 DMU_OT_USERREFS, /* ZAP */
190 DMU_OT_DDT_ZAP, /* ZAP */
191 DMU_OT_DDT_STATS, /* ZAP */
192 DMU_OT_SA, /* System attr */
193 DMU_OT_SA_MASTER_NODE, /* ZAP */
194 DMU_OT_SA_ATTR_REGISTRATION, /* ZAP */
195 DMU_OT_SA_ATTR_LAYOUTS, /* ZAP */
196 DMU_OT_SCAN_XLATE, /* ZAP */
197 DMU_OT_DEDUP, /* fake dedup BP from ddt_bp_create() */
198 DMU_OT_DEADLIST, /* ZAP */
199 DMU_OT_DEADLIST_HDR, /* UINT64 */
200 DMU_OT_DSL_CLONES, /* ZAP */
201 DMU_OT_BPOBJ_SUBOBJ, /* UINT64 */
202 /*
203 * Do not allocate new object types here. Doing so makes the on-disk
204 * format incompatible with any other format that uses the same object
205 * type number.
206 *
207 * When creating an object which does not have one of the above types
208 * use the DMU_OTN_* type with the correct byteswap and metadata
209 * values.
210 *
211 * The DMU_OTN_* types do not have entries in the dmu_ot table,
212 * use the DMU_OT_IS_METDATA() and DMU_OT_BYTESWAP() macros instead
213 * of indexing into dmu_ot directly (this works for both DMU_OT_* types
214 * and DMU_OTN_* types).
215 */
216 DMU_OT_NUMTYPES,
217
218 /*
219 * Names for valid types declared with DMU_OT().
220 */
221 DMU_OTN_UINT8_DATA = DMU_OT(DMU_BSWAP_UINT8, B_FALSE),
222 DMU_OTN_UINT8_METADATA = DMU_OT(DMU_BSWAP_UINT8, B_TRUE),
223 DMU_OTN_UINT16_DATA = DMU_OT(DMU_BSWAP_UINT16, B_FALSE),
224 DMU_OTN_UINT16_METADATA = DMU_OT(DMU_BSWAP_UINT16, B_TRUE),
225 DMU_OTN_UINT32_DATA = DMU_OT(DMU_BSWAP_UINT32, B_FALSE),
226 DMU_OTN_UINT32_METADATA = DMU_OT(DMU_BSWAP_UINT32, B_TRUE),
227 DMU_OTN_UINT64_DATA = DMU_OT(DMU_BSWAP_UINT64, B_FALSE),
228 DMU_OTN_UINT64_METADATA = DMU_OT(DMU_BSWAP_UINT64, B_TRUE),
229 DMU_OTN_ZAP_DATA = DMU_OT(DMU_BSWAP_ZAP, B_FALSE),
230 DMU_OTN_ZAP_METADATA = DMU_OT(DMU_BSWAP_ZAP, B_TRUE),
231 } dmu_object_type_t;
232
233 /*
234 * These flags are intended to be used to specify the "txg_how"
235 * parameter when calling the dmu_tx_assign() function. See the comment
236 * above dmu_tx_assign() for more details on the meaning of these flags.
237 */
238 #define TXG_NOWAIT (0ULL)
239 #define TXG_WAIT (1ULL<<0)
240 #define TXG_NOTHROTTLE (1ULL<<1)
241
242 void byteswap_uint64_array(void *buf, size_t size);
243 void byteswap_uint32_array(void *buf, size_t size);
244 void byteswap_uint16_array(void *buf, size_t size);
245 void byteswap_uint8_array(void *buf, size_t size);
246 void zap_byteswap(void *buf, size_t size);
247 void zfs_oldacl_byteswap(void *buf, size_t size);
248 void zfs_acl_byteswap(void *buf, size_t size);
249 void zfs_znode_byteswap(void *buf, size_t size);
250
251 #define DS_FIND_SNAPSHOTS (1<<0)
252 #define DS_FIND_CHILDREN (1<<1)
253 #define DS_FIND_SERIALIZE (1<<2)
254
255 /*
256 * The maximum number of bytes that can be accessed as part of one
257 * operation, including metadata.
258 */
259 #define DMU_MAX_ACCESS (32 * 1024 * 1024) /* 32MB */
260 #define DMU_MAX_DELETEBLKCNT (20480) /* ~5MB of indirect blocks */
261
262 #define DMU_USERUSED_OBJECT (-1ULL)
263 #define DMU_GROUPUSED_OBJECT (-2ULL)
264
265 /*
266 * artificial blkids for bonus buffer and spill blocks
267 */
268 #define DMU_BONUS_BLKID (-1ULL)
269 #define DMU_SPILL_BLKID (-2ULL)
270 /*
271 * Public routines to create, destroy, open, and close objsets.
272 */
273 int dmu_objset_hold(const char *name, void *tag, objset_t **osp);
274 int dmu_objset_own(const char *name, dmu_objset_type_t type,
275 boolean_t readonly, void *tag, objset_t **osp);
276 void dmu_objset_rele(objset_t *os, void *tag);
277 void dmu_objset_disown(objset_t *os, void *tag);
278 int dmu_objset_open_ds(struct dsl_dataset *ds, objset_t **osp);
279
280 void dmu_objset_evict_dbufs(objset_t *os);
281 int dmu_objset_create(const char *name, dmu_objset_type_t type, uint64_t flags,
282 void (*func)(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx), void *arg);
283 int dmu_get_recursive_snaps_nvl(char *fsname, const char *snapname,
284 struct nvlist *snaps);
285 int dmu_objset_clone(const char *name, const char *origin);
286 int dsl_destroy_snapshots_nvl(struct nvlist *snaps, boolean_t defer,
287 struct nvlist *errlist);
288 int dmu_objset_snapshot_one(const char *fsname, const char *snapname);
289 int dmu_objset_snapshot_tmp(const char *, const char *, int);
290 int dmu_objset_find(char *name, int func(const char *, void *), void *arg,
291 int flags);
292 void dmu_objset_byteswap(void *buf, size_t size);
293 int dsl_dataset_rename_snapshot(const char *fsname,
294 const char *oldsnapname, const char *newsnapname, boolean_t recursive);
295
296 typedef struct dmu_buf {
297 uint64_t db_object; /* object that this buffer is part of */
298 uint64_t db_offset; /* byte offset in this object */
299 uint64_t db_size; /* size of buffer in bytes */
300 void *db_data; /* data in buffer */
301 } dmu_buf_t;
302
303 /*
304 * The names of zap entries in the DIRECTORY_OBJECT of the MOS.
305 */
306 #define DMU_POOL_DIRECTORY_OBJECT 1
307 #define DMU_POOL_CONFIG "config"
308 #define DMU_POOL_FEATURES_FOR_WRITE "features_for_write"
309 #define DMU_POOL_FEATURES_FOR_READ "features_for_read"
310 #define DMU_POOL_FEATURE_DESCRIPTIONS "feature_descriptions"
311 #define DMU_POOL_FEATURE_ENABLED_TXG "feature_enabled_txg"
312 #define DMU_POOL_ROOT_DATASET "root_dataset"
313 #define DMU_POOL_SYNC_BPOBJ "sync_bplist"
314 #define DMU_POOL_ERRLOG_SCRUB "errlog_scrub"
315 #define DMU_POOL_ERRLOG_LAST "errlog_last"
316 #define DMU_POOL_SPARES "spares"
317 #define DMU_POOL_DEFLATE "deflate"
318 #define DMU_POOL_HISTORY "history"
319 #define DMU_POOL_PROPS "pool_props"
320 #define DMU_POOL_L2CACHE "l2cache"
321 #define DMU_POOL_TMP_USERREFS "tmp_userrefs"
322 #define DMU_POOL_DDT "DDT-%s-%s-%s"
323 #define DMU_POOL_DDT_STATS "DDT-statistics"
324 #define DMU_POOL_CREATION_VERSION "creation_version"
325 #define DMU_POOL_SCAN "scan"
326 #define DMU_POOL_FREE_BPOBJ "free_bpobj"
327 #define DMU_POOL_BPTREE_OBJ "bptree_obj"
328 #define DMU_POOL_EMPTY_BPOBJ "empty_bpobj"
329 #define DMU_POOL_CHECKSUM_SALT "org.illumos:checksum_salt"
330
331 /*
332 * Allocate an object from this objset. The range of object numbers
333 * available is (0, DN_MAX_OBJECT). Object 0 is the meta-dnode.
334 *
335 * The transaction must be assigned to a txg. The newly allocated
336 * object will be "held" in the transaction (ie. you can modify the
337 * newly allocated object in this transaction).
338 *
339 * dmu_object_alloc() chooses an object and returns it in *objectp.
340 *
341 * dmu_object_claim() allocates a specific object number. If that
342 * number is already allocated, it fails and returns EEXIST.
343 *
344 * Return 0 on success, or ENOSPC or EEXIST as specified above.
345 */
346 uint64_t dmu_object_alloc(objset_t *os, dmu_object_type_t ot,
347 int blocksize, dmu_object_type_t bonus_type, int bonus_len, dmu_tx_t *tx);
348 int dmu_object_claim(objset_t *os, uint64_t object, dmu_object_type_t ot,
349 int blocksize, dmu_object_type_t bonus_type, int bonus_len, dmu_tx_t *tx);
350 int dmu_object_reclaim(objset_t *os, uint64_t object, dmu_object_type_t ot,
351 int blocksize, dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *txp);
352
353 /*
354 * Free an object from this objset.
355 *
356 * The object's data will be freed as well (ie. you don't need to call
357 * dmu_free(object, 0, -1, tx)).
358 *
359 * The object need not be held in the transaction.
360 *
361 * If there are any holds on this object's buffers (via dmu_buf_hold()),
362 * or tx holds on the object (via dmu_tx_hold_object()), you can not
363 * free it; it fails and returns EBUSY.
364 *
365 * If the object is not allocated, it fails and returns ENOENT.
366 *
367 * Return 0 on success, or EBUSY or ENOENT as specified above.
368 */
369 int dmu_object_free(objset_t *os, uint64_t object, dmu_tx_t *tx);
370
371 /*
372 * Find the next allocated or free object.
373 *
374 * The objectp parameter is in-out. It will be updated to be the next
375 * object which is allocated. Ignore objects which have not been
376 * modified since txg.
377 *
378 * XXX Can only be called on a objset with no dirty data.
379 *
380 * Returns 0 on success, or ENOENT if there are no more objects.
381 */
382 int dmu_object_next(objset_t *os, uint64_t *objectp,
383 boolean_t hole, uint64_t txg);
384
385 /*
386 * Set the data blocksize for an object.
387 *
388 * The object cannot have any blocks allcated beyond the first. If
389 * the first block is allocated already, the new size must be greater
390 * than the current block size. If these conditions are not met,
391 * ENOTSUP will be returned.
392 *
393 * Returns 0 on success, or EBUSY if there are any holds on the object
394 * contents, or ENOTSUP as described above.
395 */
396 int dmu_object_set_blocksize(objset_t *os, uint64_t object, uint64_t size,
397 int ibs, dmu_tx_t *tx);
398
399 /*
400 * Set the checksum property on a dnode. The new checksum algorithm will
401 * apply to all newly written blocks; existing blocks will not be affected.
402 */
403 void dmu_object_set_checksum(objset_t *os, uint64_t object, uint8_t checksum,
404 dmu_tx_t *tx);
405
406 /*
407 * Set the compress property on a dnode. The new compression algorithm will
408 * apply to all newly written blocks; existing blocks will not be affected.
409 */
410 void dmu_object_set_compress(objset_t *os, uint64_t object, uint8_t compress,
411 dmu_tx_t *tx);
412
413 void
414 dmu_write_embedded(objset_t *os, uint64_t object, uint64_t offset,
415 void *data, uint8_t etype, uint8_t comp, int uncompressed_size,
416 int compressed_size, int byteorder, dmu_tx_t *tx);
417
418 /*
419 * Decide how to write a block: checksum, compression, number of copies, etc.
420 */
421 #define WP_NOFILL 0x1
422 #define WP_DMU_SYNC 0x2
423 #define WP_SPILL 0x4
424
425 void dmu_write_policy(objset_t *os, dnode_t *dn, int level, int wp,
426 struct zio_prop *zp);
427 /*
428 * The bonus data is accessed more or less like a regular buffer.
429 * You must dmu_bonus_hold() to get the buffer, which will give you a
430 * dmu_buf_t with db_offset==-1ULL, and db_size = the size of the bonus
431 * data. As with any normal buffer, you must call dmu_buf_read() to
432 * read db_data, dmu_buf_will_dirty() before modifying it, and the
433 * object must be held in an assigned transaction before calling
434 * dmu_buf_will_dirty. You may use dmu_buf_set_user() on the bonus
435 * buffer as well. You must release your hold with dmu_buf_rele().
436 *
437 * Returns ENOENT, EIO, or 0.
438 */
439 int dmu_bonus_hold(objset_t *os, uint64_t object, void *tag, dmu_buf_t **);
440 int dmu_bonus_max(void);
441 int dmu_set_bonus(dmu_buf_t *, int, dmu_tx_t *);
442 int dmu_set_bonustype(dmu_buf_t *, dmu_object_type_t, dmu_tx_t *);
443 dmu_object_type_t dmu_get_bonustype(dmu_buf_t *);
444 int dmu_rm_spill(objset_t *, uint64_t, dmu_tx_t *);
445
446 /*
447 * Special spill buffer support used by "SA" framework
448 */
449
450 int dmu_spill_hold_by_bonus(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp);
451 int dmu_spill_hold_by_dnode(dnode_t *dn, uint32_t flags,
452 void *tag, dmu_buf_t **dbp);
453 int dmu_spill_hold_existing(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp);
454
455 /*
456 * Obtain the DMU buffer from the specified object which contains the
457 * specified offset. dmu_buf_hold() puts a "hold" on the buffer, so
458 * that it will remain in memory. You must release the hold with
459 * dmu_buf_rele(). You musn't access the dmu_buf_t after releasing your
460 * hold. You must have a hold on any dmu_buf_t* you pass to the DMU.
461 *
462 * You must call dmu_buf_read, dmu_buf_will_dirty, or dmu_buf_will_fill
463 * on the returned buffer before reading or writing the buffer's
464 * db_data. The comments for those routines describe what particular
465 * operations are valid after calling them.
466 *
467 * The object number must be a valid, allocated object number.
468 */
469 int dmu_buf_hold(objset_t *os, uint64_t object, uint64_t offset,
470 void *tag, dmu_buf_t **, int flags);
471 int dmu_buf_hold_by_dnode(dnode_t *dn, uint64_t offset,
472 void *tag, dmu_buf_t **dbp, int flags);
473
474 /*
475 * Add a reference to a dmu buffer that has already been held via
476 * dmu_buf_hold() in the current context.
477 */
478 void dmu_buf_add_ref(dmu_buf_t *db, void* tag);
479
480 /*
481 * Attempt to add a reference to a dmu buffer that is in an unknown state,
482 * using a pointer that may have been invalidated by eviction processing.
483 * The request will succeed if the passed in dbuf still represents the
484 * same os/object/blkid, is ineligible for eviction, and has at least
485 * one hold by a user other than the syncer.
486 */
487 boolean_t dmu_buf_try_add_ref(dmu_buf_t *, objset_t *os, uint64_t object,
488 uint64_t blkid, void *tag);
489
490 void dmu_buf_rele(dmu_buf_t *db, void *tag);
491 uint64_t dmu_buf_refcount(dmu_buf_t *db);
492
493 /*
494 * dmu_buf_hold_array holds the DMU buffers which contain all bytes in a
495 * range of an object. A pointer to an array of dmu_buf_t*'s is
496 * returned (in *dbpp).
497 *
498 * dmu_buf_rele_array releases the hold on an array of dmu_buf_t*'s, and
499 * frees the array. The hold on the array of buffers MUST be released
500 * with dmu_buf_rele_array. You can NOT release the hold on each buffer
501 * individually with dmu_buf_rele.
502 */
503 int dmu_buf_hold_array_by_bonus(dmu_buf_t *db, uint64_t offset,
504 uint64_t length, boolean_t read, void *tag,
505 int *numbufsp, dmu_buf_t ***dbpp);
506 void dmu_buf_rele_array(dmu_buf_t **, int numbufs, void *tag);
507
508 typedef void dmu_buf_evict_func_t(void *user_ptr);
509
510 /*
511 * A DMU buffer user object may be associated with a dbuf for the
512 * duration of its lifetime. This allows the user of a dbuf (client)
513 * to attach private data to a dbuf (e.g. in-core only data such as a
514 * dnode_children_t, zap_t, or zap_leaf_t) and be optionally notified
515 * when that dbuf has been evicted. Clients typically respond to the
516 * eviction notification by freeing their private data, thus ensuring
517 * the same lifetime for both dbuf and private data.
518 *
519 * The mapping from a dmu_buf_user_t to any client private data is the
520 * client's responsibility. All current consumers of the API with private
521 * data embed a dmu_buf_user_t as the first member of the structure for
522 * their private data. This allows conversions between the two types
523 * with a simple cast. Since the DMU buf user API never needs access
524 * to the private data, other strategies can be employed if necessary
525 * or convenient for the client (e.g. using container_of() to do the
526 * conversion for private data that cannot have the dmu_buf_user_t as
527 * its first member).
528 *
529 * Eviction callbacks are executed without the dbuf mutex held or any
530 * other type of mechanism to guarantee that the dbuf is still available.
531 * For this reason, users must assume the dbuf has already been freed
532 * and not reference the dbuf from the callback context.
533 *
534 * Users requesting "immediate eviction" are notified as soon as the dbuf
535 * is only referenced by dirty records (dirties == holds). Otherwise the
536 * notification occurs after eviction processing for the dbuf begins.
537 */
538 typedef struct dmu_buf_user {
539 /*
540 * Asynchronous user eviction callback state.
541 */
542 taskq_ent_t dbu_tqent;
543
544 /* This instance's eviction function pointer. */
545 dmu_buf_evict_func_t *dbu_evict_func;
546 #ifdef ZFS_DEBUG
547 /*
548 * Pointer to user's dbuf pointer. NULL for clients that do
549 * not associate a dbuf with their user data.
550 *
551 * The dbuf pointer is cleared upon eviction so as to catch
552 * use-after-evict bugs in clients.
553 */
554 dmu_buf_t **dbu_clear_on_evict_dbufp;
555 #endif
556 } dmu_buf_user_t;
557
558 /*
559 * Initialize the given dmu_buf_user_t instance with the eviction function
560 * evict_func, to be called when the user is evicted.
561 *
562 * NOTE: This function should only be called once on a given dmu_buf_user_t.
563 * To allow enforcement of this, dbu must already be zeroed on entry.
564 */
565 #ifdef __lint
566 /* Very ugly, but it beats issuing suppression directives in many Makefiles. */
567 extern void
568 dmu_buf_init_user(dmu_buf_user_t *dbu, dmu_buf_evict_func_t *evict_func,
569 dmu_buf_t **clear_on_evict_dbufp);
570 #else /* __lint */
571 static inline void
dmu_buf_init_user(dmu_buf_user_t * dbu,dmu_buf_evict_func_t * evict_func,dmu_buf_t ** clear_on_evict_dbufp)572 dmu_buf_init_user(dmu_buf_user_t *dbu, dmu_buf_evict_func_t *evict_func,
573 dmu_buf_t **clear_on_evict_dbufp)
574 {
575 ASSERT(dbu->dbu_evict_func == NULL);
576 ASSERT(evict_func != NULL);
577 dbu->dbu_evict_func = evict_func;
578 #ifdef ZFS_DEBUG
579 dbu->dbu_clear_on_evict_dbufp = clear_on_evict_dbufp;
580 #endif
581 }
582 #endif /* __lint */
583
584 /*
585 * Attach user data to a dbuf and mark it for normal (when the dbuf's
586 * data is cleared or its reference count goes to zero) eviction processing.
587 *
588 * Returns NULL on success, or the existing user if another user currently
589 * owns the buffer.
590 */
591 void *dmu_buf_set_user(dmu_buf_t *db, dmu_buf_user_t *user);
592
593 /*
594 * Attach user data to a dbuf and mark it for immediate (its dirty and
595 * reference counts are equal) eviction processing.
596 *
597 * Returns NULL on success, or the existing user if another user currently
598 * owns the buffer.
599 */
600 void *dmu_buf_set_user_ie(dmu_buf_t *db, dmu_buf_user_t *user);
601
602 /*
603 * Replace the current user of a dbuf.
604 *
605 * If given the current user of a dbuf, replaces the dbuf's user with
606 * "new_user" and returns the user data pointer that was replaced.
607 * Otherwise returns the current, and unmodified, dbuf user pointer.
608 */
609 void *dmu_buf_replace_user(dmu_buf_t *db,
610 dmu_buf_user_t *old_user, dmu_buf_user_t *new_user);
611
612 /*
613 * Remove the specified user data for a DMU buffer.
614 *
615 * Returns the user that was removed on success, or the current user if
616 * another user currently owns the buffer.
617 */
618 void *dmu_buf_remove_user(dmu_buf_t *db, dmu_buf_user_t *user);
619
620 /*
621 * Returns the user data (dmu_buf_user_t *) associated with this dbuf.
622 */
623 void *dmu_buf_get_user(dmu_buf_t *db);
624
625 objset_t *dmu_buf_get_objset(dmu_buf_t *db);
626 dnode_t *dmu_buf_dnode_enter(dmu_buf_t *db);
627 void dmu_buf_dnode_exit(dmu_buf_t *db);
628
629 /* Block until any in-progress dmu buf user evictions complete. */
630 void dmu_buf_user_evict_wait(void);
631
632 /*
633 * Returns the blkptr associated with this dbuf, or NULL if not set.
634 */
635 struct blkptr *dmu_buf_get_blkptr(dmu_buf_t *db);
636
637 /*
638 * Indicate that you are going to modify the buffer's data (db_data).
639 *
640 * The transaction (tx) must be assigned to a txg (ie. you've called
641 * dmu_tx_assign()). The buffer's object must be held in the tx
642 * (ie. you've called dmu_tx_hold_object(tx, db->db_object)).
643 */
644 void dmu_buf_will_dirty(dmu_buf_t *db, dmu_tx_t *tx);
645
646 /*
647 * Tells if the given dbuf is freeable.
648 */
649 boolean_t dmu_buf_freeable(dmu_buf_t *);
650
651 /*
652 * You must create a transaction, then hold the objects which you will
653 * (or might) modify as part of this transaction. Then you must assign
654 * the transaction to a transaction group. Once the transaction has
655 * been assigned, you can modify buffers which belong to held objects as
656 * part of this transaction. You can't modify buffers before the
657 * transaction has been assigned; you can't modify buffers which don't
658 * belong to objects which this transaction holds; you can't hold
659 * objects once the transaction has been assigned. You may hold an
660 * object which you are going to free (with dmu_object_free()), but you
661 * don't have to.
662 *
663 * You can abort the transaction before it has been assigned.
664 *
665 * Note that you may hold buffers (with dmu_buf_hold) at any time,
666 * regardless of transaction state.
667 */
668
669 #define DMU_NEW_OBJECT (-1ULL)
670 #define DMU_OBJECT_END (-1ULL)
671
672 dmu_tx_t *dmu_tx_create(objset_t *os);
673 void dmu_tx_hold_write(dmu_tx_t *tx, uint64_t object, uint64_t off, int len);
674 void dmu_tx_hold_free(dmu_tx_t *tx, uint64_t object, uint64_t off,
675 uint64_t len);
676 void dmu_tx_hold_zap(dmu_tx_t *tx, uint64_t object, int add, const char *name);
677 void dmu_tx_hold_bonus(dmu_tx_t *tx, uint64_t object);
678 void dmu_tx_hold_spill(dmu_tx_t *tx, uint64_t object);
679 void dmu_tx_hold_sa(dmu_tx_t *tx, struct sa_handle *hdl, boolean_t may_grow);
680 void dmu_tx_hold_sa_create(dmu_tx_t *tx, int total_size);
681 void dmu_tx_abort(dmu_tx_t *tx);
682 int dmu_tx_assign(dmu_tx_t *tx, uint64_t txg_how);
683 void dmu_tx_wait(dmu_tx_t *tx);
684 void dmu_tx_commit(dmu_tx_t *tx);
685 void dmu_tx_mark_netfree(dmu_tx_t *tx);
686
687 /*
688 * To register a commit callback, dmu_tx_callback_register() must be called.
689 *
690 * dcb_data is a pointer to caller private data that is passed on as a
691 * callback parameter. The caller is responsible for properly allocating and
692 * freeing it.
693 *
694 * When registering a callback, the transaction must be already created, but
695 * it cannot be committed or aborted. It can be assigned to a txg or not.
696 *
697 * The callback will be called after the transaction has been safely written
698 * to stable storage and will also be called if the dmu_tx is aborted.
699 * If there is any error which prevents the transaction from being committed to
700 * disk, the callback will be called with a value of error != 0.
701 */
702 typedef void dmu_tx_callback_func_t(void *dcb_data, int error);
703
704 void dmu_tx_callback_register(dmu_tx_t *tx, dmu_tx_callback_func_t *dcb_func,
705 void *dcb_data);
706
707 /*
708 * Free up the data blocks for a defined range of a file. If size is
709 * -1, the range from offset to end-of-file is freed.
710 */
711 int dmu_free_range(objset_t *os, uint64_t object, uint64_t offset,
712 uint64_t size, dmu_tx_t *tx);
713 int dmu_free_long_range(objset_t *os, uint64_t object, uint64_t offset,
714 uint64_t size);
715 int dmu_free_long_object(objset_t *os, uint64_t object);
716
717 /*
718 * Convenience functions.
719 *
720 * Canfail routines will return 0 on success, or an errno if there is a
721 * nonrecoverable I/O error.
722 */
723 #define DMU_READ_PREFETCH 0 /* prefetch */
724 #define DMU_READ_NO_PREFETCH 1 /* don't prefetch */
725 int dmu_read(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
726 void *buf, uint32_t flags);
727 void dmu_write(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
728 const void *buf, dmu_tx_t *tx);
729 void dmu_prealloc(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
730 dmu_tx_t *tx);
731 int dmu_read_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size);
732 int dmu_read_uio_dbuf(dmu_buf_t *zdb, struct uio *uio, uint64_t size);
733 int dmu_write_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size,
734 dmu_tx_t *tx);
735 int dmu_write_uio_dbuf(dmu_buf_t *zdb, struct uio *uio, uint64_t size,
736 dmu_tx_t *tx);
737 #ifdef _KERNEL
738 #ifdef illumos
739 int dmu_write_pages(objset_t *os, uint64_t object, uint64_t offset,
740 uint64_t size, struct page *pp, dmu_tx_t *tx);
741 #else
742 int dmu_write_pages(objset_t *os, uint64_t object, uint64_t offset,
743 uint64_t size, struct vm_page **ppa, dmu_tx_t *tx);
744 #endif
745 #endif
746 struct arc_buf *dmu_request_arcbuf(dmu_buf_t *handle, int size);
747 void dmu_return_arcbuf(struct arc_buf *buf);
748 void dmu_assign_arcbuf(dmu_buf_t *handle, uint64_t offset, struct arc_buf *buf,
749 dmu_tx_t *tx);
750 int dmu_xuio_init(struct xuio *uio, int niov);
751 void dmu_xuio_fini(struct xuio *uio);
752 int dmu_xuio_add(struct xuio *uio, struct arc_buf *abuf, offset_t off,
753 size_t n);
754 int dmu_xuio_cnt(struct xuio *uio);
755 struct arc_buf *dmu_xuio_arcbuf(struct xuio *uio, int i);
756 void dmu_xuio_clear(struct xuio *uio, int i);
757 void xuio_stat_wbuf_copied();
758 void xuio_stat_wbuf_nocopy();
759
760 extern boolean_t zfs_prefetch_disable;
761 extern int zfs_max_recordsize;
762
763 /*
764 * Asynchronously try to read in the data.
765 */
766 void dmu_prefetch(objset_t *os, uint64_t object, int64_t level, uint64_t offset,
767 uint64_t len, enum zio_priority pri);
768
769 typedef struct dmu_object_info {
770 /* All sizes are in bytes unless otherwise indicated. */
771 uint32_t doi_data_block_size;
772 uint32_t doi_metadata_block_size;
773 dmu_object_type_t doi_type;
774 dmu_object_type_t doi_bonus_type;
775 uint64_t doi_bonus_size;
776 uint8_t doi_indirection; /* 2 = dnode->indirect->data */
777 uint8_t doi_checksum;
778 uint8_t doi_compress;
779 uint8_t doi_nblkptr;
780 uint8_t doi_pad[4];
781 uint64_t doi_physical_blocks_512; /* data + metadata, 512b blks */
782 uint64_t doi_max_offset;
783 uint64_t doi_fill_count; /* number of non-empty blocks */
784 } dmu_object_info_t;
785
786 typedef void arc_byteswap_func_t(void *buf, size_t size);
787
788 typedef struct dmu_object_type_info {
789 dmu_object_byteswap_t ot_byteswap;
790 boolean_t ot_metadata;
791 char *ot_name;
792 } dmu_object_type_info_t;
793
794 typedef struct dmu_object_byteswap_info {
795 arc_byteswap_func_t *ob_func;
796 char *ob_name;
797 } dmu_object_byteswap_info_t;
798
799 extern const dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES];
800 extern const dmu_object_byteswap_info_t dmu_ot_byteswap[DMU_BSWAP_NUMFUNCS];
801
802 /*
803 * Get information on a DMU object.
804 *
805 * Return 0 on success or ENOENT if object is not allocated.
806 *
807 * If doi is NULL, just indicates whether the object exists.
808 */
809 int dmu_object_info(objset_t *os, uint64_t object, dmu_object_info_t *doi);
810 /* Like dmu_object_info, but faster if you have a held dnode in hand. */
811 void dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi);
812 /* Like dmu_object_info, but faster if you have a held dbuf in hand. */
813 void dmu_object_info_from_db(dmu_buf_t *db, dmu_object_info_t *doi);
814 /*
815 * Like dmu_object_info_from_db, but faster still when you only care about
816 * the size. This is specifically optimized for zfs_getattr().
817 */
818 void dmu_object_size_from_db(dmu_buf_t *db, uint32_t *blksize,
819 u_longlong_t *nblk512);
820
821 typedef struct dmu_objset_stats {
822 uint64_t dds_num_clones; /* number of clones of this */
823 uint64_t dds_creation_txg;
824 uint64_t dds_guid;
825 dmu_objset_type_t dds_type;
826 uint8_t dds_is_snapshot;
827 uint8_t dds_inconsistent;
828 char dds_origin[ZFS_MAX_DATASET_NAME_LEN];
829 } dmu_objset_stats_t;
830
831 /*
832 * Get stats on a dataset.
833 */
834 void dmu_objset_fast_stat(objset_t *os, dmu_objset_stats_t *stat);
835
836 /*
837 * Add entries to the nvlist for all the objset's properties. See
838 * zfs_prop_table[] and zfs(1m) for details on the properties.
839 */
840 void dmu_objset_stats(objset_t *os, struct nvlist *nv);
841
842 /*
843 * Get the space usage statistics for statvfs().
844 *
845 * refdbytes is the amount of space "referenced" by this objset.
846 * availbytes is the amount of space available to this objset, taking
847 * into account quotas & reservations, assuming that no other objsets
848 * use the space first. These values correspond to the 'referenced' and
849 * 'available' properties, described in the zfs(1m) manpage.
850 *
851 * usedobjs and availobjs are the number of objects currently allocated,
852 * and available.
853 */
854 void dmu_objset_space(objset_t *os, uint64_t *refdbytesp, uint64_t *availbytesp,
855 uint64_t *usedobjsp, uint64_t *availobjsp);
856
857 /*
858 * The fsid_guid is a 56-bit ID that can change to avoid collisions.
859 * (Contrast with the ds_guid which is a 64-bit ID that will never
860 * change, so there is a small probability that it will collide.)
861 */
862 uint64_t dmu_objset_fsid_guid(objset_t *os);
863
864 /*
865 * Get the [cm]time for an objset's snapshot dir
866 */
867 timestruc_t dmu_objset_snap_cmtime(objset_t *os);
868
869 int dmu_objset_is_snapshot(objset_t *os);
870
871 extern struct spa *dmu_objset_spa(objset_t *os);
872 extern struct zilog *dmu_objset_zil(objset_t *os);
873 extern struct dsl_pool *dmu_objset_pool(objset_t *os);
874 extern struct dsl_dataset *dmu_objset_ds(objset_t *os);
875 extern void dmu_objset_name(objset_t *os, char *buf);
876 extern dmu_objset_type_t dmu_objset_type(objset_t *os);
877 extern uint64_t dmu_objset_id(objset_t *os);
878 extern zfs_sync_type_t dmu_objset_syncprop(objset_t *os);
879 extern zfs_logbias_op_t dmu_objset_logbias(objset_t *os);
880 extern int dmu_snapshot_list_next(objset_t *os, int namelen, char *name,
881 uint64_t *id, uint64_t *offp, boolean_t *case_conflict);
882 extern int dmu_snapshot_realname(objset_t *os, char *name, char *real,
883 int maxlen, boolean_t *conflict);
884 extern int dmu_dir_list_next(objset_t *os, int namelen, char *name,
885 uint64_t *idp, uint64_t *offp);
886
887 typedef int objset_used_cb_t(dmu_object_type_t bonustype,
888 void *bonus, uint64_t *userp, uint64_t *groupp);
889 extern void dmu_objset_register_type(dmu_objset_type_t ost,
890 objset_used_cb_t *cb);
891 extern void dmu_objset_set_user(objset_t *os, void *user_ptr);
892 extern void *dmu_objset_get_user(objset_t *os);
893
894 /*
895 * Return the txg number for the given assigned transaction.
896 */
897 uint64_t dmu_tx_get_txg(dmu_tx_t *tx);
898
899 /*
900 * Synchronous write.
901 * If a parent zio is provided this function initiates a write on the
902 * provided buffer as a child of the parent zio.
903 * In the absence of a parent zio, the write is completed synchronously.
904 * At write completion, blk is filled with the bp of the written block.
905 * Note that while the data covered by this function will be on stable
906 * storage when the write completes this new data does not become a
907 * permanent part of the file until the associated transaction commits.
908 */
909
910 /*
911 * {zfs,zvol,ztest}_get_done() args
912 */
913 typedef struct zgd {
914 struct zilog *zgd_zilog;
915 struct blkptr *zgd_bp;
916 dmu_buf_t *zgd_db;
917 struct rl *zgd_rl;
918 void *zgd_private;
919 } zgd_t;
920
921 typedef void dmu_sync_cb_t(zgd_t *arg, int error);
922 int dmu_sync(struct zio *zio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd);
923
924 /*
925 * Find the next hole or data block in file starting at *off
926 * Return found offset in *off. Return ESRCH for end of file.
927 */
928 int dmu_offset_next(objset_t *os, uint64_t object, boolean_t hole,
929 uint64_t *off);
930
931 /*
932 * Check if a DMU object has any dirty blocks. If so, sync out
933 * all pending transaction groups. Otherwise, this function
934 * does not alter DMU state. This could be improved to only sync
935 * out the necessary transaction groups for this particular
936 * object.
937 */
938 int dmu_object_wait_synced(objset_t *os, uint64_t object);
939
940 /*
941 * Initial setup and final teardown.
942 */
943 extern void dmu_init(void);
944 extern void dmu_fini(void);
945
946 typedef void (*dmu_traverse_cb_t)(objset_t *os, void *arg, struct blkptr *bp,
947 uint64_t object, uint64_t offset, int len);
948 void dmu_traverse_objset(objset_t *os, uint64_t txg_start,
949 dmu_traverse_cb_t cb, void *arg);
950 int dmu_diff(const char *tosnap_name, const char *fromsnap_name,
951 struct file *fp, offset_t *offp);
952
953 /* CRC64 table */
954 #define ZFS_CRC64_POLY 0xC96C5795D7870F42ULL /* ECMA-182, reflected form */
955 extern uint64_t zfs_crc64_table[256];
956
957 extern int zfs_mdcomp_disable;
958
959 #ifdef __cplusplus
960 }
961 #endif
962
963 #endif /* _SYS_DMU_H */
964