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, 2017 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/inttypes.h>
49 #include <sys/cred.h>
50 #include <sys/fs/zfs.h>
51 #include <sys/zio_compress.h>
52 #include <sys/zio_priority.h>
53
54 #ifdef __cplusplus
55 extern "C" {
56 #endif
57
58 struct uio;
59 struct xuio;
60 struct page;
61 struct vnode;
62 struct spa;
63 struct zilog;
64 struct zio;
65 struct blkptr;
66 struct zap_cursor;
67 struct dsl_dataset;
68 struct dsl_pool;
69 struct dnode;
70 struct drr_begin;
71 struct drr_end;
72 struct zbookmark_phys;
73 struct spa;
74 struct nvlist;
75 struct arc_buf;
76 struct zio_prop;
77 struct sa_handle;
78
79 typedef struct objset objset_t;
80 typedef struct dmu_tx dmu_tx_t;
81 typedef struct dsl_dir dsl_dir_t;
82 typedef struct dnode dnode_t;
83
84 typedef enum dmu_object_byteswap {
85 DMU_BSWAP_UINT8,
86 DMU_BSWAP_UINT16,
87 DMU_BSWAP_UINT32,
88 DMU_BSWAP_UINT64,
89 DMU_BSWAP_ZAP,
90 DMU_BSWAP_DNODE,
91 DMU_BSWAP_OBJSET,
92 DMU_BSWAP_ZNODE,
93 DMU_BSWAP_OLDACL,
94 DMU_BSWAP_ACL,
95 /*
96 * Allocating a new byteswap type number makes the on-disk format
97 * incompatible with any other format that uses the same number.
98 *
99 * Data can usually be structured to work with one of the
100 * DMU_BSWAP_UINT* or DMU_BSWAP_ZAP types.
101 */
102 DMU_BSWAP_NUMFUNCS
103 } dmu_object_byteswap_t;
104
105 #define DMU_OT_NEWTYPE 0x80
106 #define DMU_OT_METADATA 0x40
107 #define DMU_OT_BYTESWAP_MASK 0x3f
108
109 /*
110 * Defines a uint8_t object type. Object types specify if the data
111 * in the object is metadata (boolean) and how to byteswap the data
112 * (dmu_object_byteswap_t).
113 */
114 #define DMU_OT(byteswap, metadata) \
115 (DMU_OT_NEWTYPE | \
116 ((metadata) ? DMU_OT_METADATA : 0) | \
117 ((byteswap) & DMU_OT_BYTESWAP_MASK))
118
119 #define DMU_OT_IS_VALID(ot) (((ot) & DMU_OT_NEWTYPE) ? \
120 ((ot) & DMU_OT_BYTESWAP_MASK) < DMU_BSWAP_NUMFUNCS : \
121 (ot) < DMU_OT_NUMTYPES)
122
123 #define DMU_OT_IS_METADATA(ot) (((ot) & DMU_OT_NEWTYPE) ? \
124 ((ot) & DMU_OT_METADATA) : \
125 dmu_ot[(ot)].ot_metadata)
126
127 /*
128 * These object types use bp_fill != 1 for their L0 bp's. Therefore they can't
129 * have their data embedded (i.e. use a BP_IS_EMBEDDED() bp), because bp_fill
130 * is repurposed for embedded BPs.
131 */
132 #define DMU_OT_HAS_FILL(ot) \
133 ((ot) == DMU_OT_DNODE || (ot) == DMU_OT_OBJSET)
134
135 #define DMU_OT_BYTESWAP(ot) (((ot) & DMU_OT_NEWTYPE) ? \
136 ((ot) & DMU_OT_BYTESWAP_MASK) : \
137 dmu_ot[(ot)].ot_byteswap)
138
139 typedef enum dmu_object_type {
140 DMU_OT_NONE,
141 /* general: */
142 DMU_OT_OBJECT_DIRECTORY, /* ZAP */
143 DMU_OT_OBJECT_ARRAY, /* UINT64 */
144 DMU_OT_PACKED_NVLIST, /* UINT8 (XDR by nvlist_pack/unpack) */
145 DMU_OT_PACKED_NVLIST_SIZE, /* UINT64 */
146 DMU_OT_BPOBJ, /* UINT64 */
147 DMU_OT_BPOBJ_HDR, /* UINT64 */
148 /* spa: */
149 DMU_OT_SPACE_MAP_HEADER, /* UINT64 */
150 DMU_OT_SPACE_MAP, /* UINT64 */
151 /* zil: */
152 DMU_OT_INTENT_LOG, /* UINT64 */
153 /* dmu: */
154 DMU_OT_DNODE, /* DNODE */
155 DMU_OT_OBJSET, /* OBJSET */
156 /* dsl: */
157 DMU_OT_DSL_DIR, /* UINT64 */
158 DMU_OT_DSL_DIR_CHILD_MAP, /* ZAP */
159 DMU_OT_DSL_DS_SNAP_MAP, /* ZAP */
160 DMU_OT_DSL_PROPS, /* ZAP */
161 DMU_OT_DSL_DATASET, /* UINT64 */
162 /* zpl: */
163 DMU_OT_ZNODE, /* ZNODE */
164 DMU_OT_OLDACL, /* Old ACL */
165 DMU_OT_PLAIN_FILE_CONTENTS, /* UINT8 */
166 DMU_OT_DIRECTORY_CONTENTS, /* ZAP */
167 DMU_OT_MASTER_NODE, /* ZAP */
168 DMU_OT_UNLINKED_SET, /* ZAP */
169 /* zvol: */
170 DMU_OT_ZVOL, /* UINT8 */
171 DMU_OT_ZVOL_PROP, /* ZAP */
172 /* other; for testing only! */
173 DMU_OT_PLAIN_OTHER, /* UINT8 */
174 DMU_OT_UINT64_OTHER, /* UINT64 */
175 DMU_OT_ZAP_OTHER, /* ZAP */
176 /* new object types: */
177 DMU_OT_ERROR_LOG, /* ZAP */
178 DMU_OT_SPA_HISTORY, /* UINT8 */
179 DMU_OT_SPA_HISTORY_OFFSETS, /* spa_his_phys_t */
180 DMU_OT_POOL_PROPS, /* ZAP */
181 DMU_OT_DSL_PERMS, /* ZAP */
182 DMU_OT_ACL, /* ACL */
183 DMU_OT_SYSACL, /* SYSACL */
184 DMU_OT_FUID, /* FUID table (Packed NVLIST UINT8) */
185 DMU_OT_FUID_SIZE, /* FUID table size UINT64 */
186 DMU_OT_NEXT_CLONES, /* ZAP */
187 DMU_OT_SCAN_QUEUE, /* ZAP */
188 DMU_OT_USERGROUP_USED, /* ZAP */
189 DMU_OT_USERGROUP_QUOTA, /* ZAP */
190 DMU_OT_USERREFS, /* ZAP */
191 DMU_OT_DDT_ZAP, /* ZAP */
192 DMU_OT_DDT_STATS, /* ZAP */
193 DMU_OT_SA, /* System attr */
194 DMU_OT_SA_MASTER_NODE, /* ZAP */
195 DMU_OT_SA_ATTR_REGISTRATION, /* ZAP */
196 DMU_OT_SA_ATTR_LAYOUTS, /* ZAP */
197 DMU_OT_SCAN_XLATE, /* ZAP */
198 DMU_OT_DEDUP, /* fake dedup BP from ddt_bp_create() */
199 DMU_OT_DEADLIST, /* ZAP */
200 DMU_OT_DEADLIST_HDR, /* UINT64 */
201 DMU_OT_DSL_CLONES, /* ZAP */
202 DMU_OT_BPOBJ_SUBOBJ, /* UINT64 */
203 /*
204 * Do not allocate new object types here. Doing so makes the on-disk
205 * format incompatible with any other format that uses the same object
206 * type number.
207 *
208 * When creating an object which does not have one of the above types
209 * use the DMU_OTN_* type with the correct byteswap and metadata
210 * values.
211 *
212 * The DMU_OTN_* types do not have entries in the dmu_ot table,
213 * use the DMU_OT_IS_METDATA() and DMU_OT_BYTESWAP() macros instead
214 * of indexing into dmu_ot directly (this works for both DMU_OT_* types
215 * and DMU_OTN_* types).
216 */
217 DMU_OT_NUMTYPES,
218
219 /*
220 * Names for valid types declared with DMU_OT().
221 */
222 DMU_OTN_UINT8_DATA = DMU_OT(DMU_BSWAP_UINT8, B_FALSE),
223 DMU_OTN_UINT8_METADATA = DMU_OT(DMU_BSWAP_UINT8, B_TRUE),
224 DMU_OTN_UINT16_DATA = DMU_OT(DMU_BSWAP_UINT16, B_FALSE),
225 DMU_OTN_UINT16_METADATA = DMU_OT(DMU_BSWAP_UINT16, B_TRUE),
226 DMU_OTN_UINT32_DATA = DMU_OT(DMU_BSWAP_UINT32, B_FALSE),
227 DMU_OTN_UINT32_METADATA = DMU_OT(DMU_BSWAP_UINT32, B_TRUE),
228 DMU_OTN_UINT64_DATA = DMU_OT(DMU_BSWAP_UINT64, B_FALSE),
229 DMU_OTN_UINT64_METADATA = DMU_OT(DMU_BSWAP_UINT64, B_TRUE),
230 DMU_OTN_ZAP_DATA = DMU_OT(DMU_BSWAP_ZAP, B_FALSE),
231 DMU_OTN_ZAP_METADATA = DMU_OT(DMU_BSWAP_ZAP, B_TRUE),
232 } dmu_object_type_t;
233
234 /*
235 * These flags are intended to be used to specify the "txg_how"
236 * parameter when calling the dmu_tx_assign() function. See the comment
237 * above dmu_tx_assign() for more details on the meaning of these flags.
238 */
239 #define TXG_NOWAIT (0ULL)
240 #define TXG_WAIT (1ULL<<0)
241 #define TXG_NOTHROTTLE (1ULL<<1)
242
243 void byteswap_uint64_array(void *buf, size_t size);
244 void byteswap_uint32_array(void *buf, size_t size);
245 void byteswap_uint16_array(void *buf, size_t size);
246 void byteswap_uint8_array(void *buf, size_t size);
247 void zap_byteswap(void *buf, size_t size);
248 void zfs_oldacl_byteswap(void *buf, size_t size);
249 void zfs_acl_byteswap(void *buf, size_t size);
250 void zfs_znode_byteswap(void *buf, size_t size);
251
252 #define DS_FIND_SNAPSHOTS (1<<0)
253 #define DS_FIND_CHILDREN (1<<1)
254 #define DS_FIND_SERIALIZE (1<<2)
255
256 /*
257 * The maximum number of bytes that can be accessed as part of one
258 * operation, including metadata.
259 */
260 #define DMU_MAX_ACCESS (32 * 1024 * 1024) /* 32MB */
261 #define DMU_MAX_DELETEBLKCNT (20480) /* ~5MB of indirect blocks */
262
263 #define DMU_USERUSED_OBJECT (-1ULL)
264 #define DMU_GROUPUSED_OBJECT (-2ULL)
265
266 /*
267 * artificial blkids for bonus buffer and spill blocks
268 */
269 #define DMU_BONUS_BLKID (-1ULL)
270 #define DMU_SPILL_BLKID (-2ULL)
271 /*
272 * Public routines to create, destroy, open, and close objsets.
273 */
274 int dmu_objset_hold(const char *name, void *tag, objset_t **osp);
275 int dmu_objset_own(const char *name, dmu_objset_type_t type,
276 boolean_t readonly, void *tag, objset_t **osp);
277 void dmu_objset_rele(objset_t *os, void *tag);
278 void dmu_objset_disown(objset_t *os, void *tag);
279 int dmu_objset_open_ds(struct dsl_dataset *ds, objset_t **osp);
280
281 void dmu_objset_evict_dbufs(objset_t *os);
282 int dmu_objset_create(const char *name, dmu_objset_type_t type, uint64_t flags,
283 void (*func)(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx), void *arg);
284 int dmu_objset_clone(const char *name, const char *origin);
285 int dsl_destroy_snapshots_nvl(struct nvlist *snaps, boolean_t defer,
286 struct nvlist *errlist);
287 int dmu_objset_snapshot_one(const char *fsname, const char *snapname);
288 int dmu_objset_snapshot_tmp(const char *, const char *, int);
289 int dmu_objset_find(char *name, int func(const char *, void *), void *arg,
290 int flags);
291 void dmu_objset_byteswap(void *buf, size_t size);
292 int dsl_dataset_rename_snapshot(const char *fsname,
293 const char *oldsnapname, const char *newsnapname, boolean_t recursive);
294 int dmu_objset_remap_indirects(const char *fsname);
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 #define DMU_POOL_VDEV_ZAP_MAP "com.delphix:vdev_zap_map"
331 #define DMU_POOL_REMOVING "com.delphix:removing"
332 #define DMU_POOL_OBSOLETE_BPOBJ "com.delphix:obsolete_bpobj"
333 #define DMU_POOL_CONDENSING_INDIRECT "com.delphix:condensing_indirect"
334
335 /*
336 * Allocate an object from this objset. The range of object numbers
337 * available is (0, DN_MAX_OBJECT). Object 0 is the meta-dnode.
338 *
339 * The transaction must be assigned to a txg. The newly allocated
340 * object will be "held" in the transaction (ie. you can modify the
341 * newly allocated object in this transaction).
342 *
343 * dmu_object_alloc() chooses an object and returns it in *objectp.
344 *
345 * dmu_object_claim() allocates a specific object number. If that
346 * number is already allocated, it fails and returns EEXIST.
347 *
348 * Return 0 on success, or ENOSPC or EEXIST as specified above.
349 */
350 uint64_t dmu_object_alloc(objset_t *os, dmu_object_type_t ot,
351 int blocksize, dmu_object_type_t bonus_type, int bonus_len, dmu_tx_t *tx);
352 int dmu_object_claim(objset_t *os, uint64_t object, dmu_object_type_t ot,
353 int blocksize, dmu_object_type_t bonus_type, int bonus_len, dmu_tx_t *tx);
354 int dmu_object_reclaim(objset_t *os, uint64_t object, dmu_object_type_t ot,
355 int blocksize, dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *txp);
356
357 /*
358 * Free an object from this objset.
359 *
360 * The object's data will be freed as well (ie. you don't need to call
361 * dmu_free(object, 0, -1, tx)).
362 *
363 * The object need not be held in the transaction.
364 *
365 * If there are any holds on this object's buffers (via dmu_buf_hold()),
366 * or tx holds on the object (via dmu_tx_hold_object()), you can not
367 * free it; it fails and returns EBUSY.
368 *
369 * If the object is not allocated, it fails and returns ENOENT.
370 *
371 * Return 0 on success, or EBUSY or ENOENT as specified above.
372 */
373 int dmu_object_free(objset_t *os, uint64_t object, dmu_tx_t *tx);
374
375 /*
376 * Find the next allocated or free object.
377 *
378 * The objectp parameter is in-out. It will be updated to be the next
379 * object which is allocated. Ignore objects which have not been
380 * modified since txg.
381 *
382 * XXX Can only be called on a objset with no dirty data.
383 *
384 * Returns 0 on success, or ENOENT if there are no more objects.
385 */
386 int dmu_object_next(objset_t *os, uint64_t *objectp,
387 boolean_t hole, uint64_t txg);
388
389 /*
390 * Set the data blocksize for an object.
391 *
392 * The object cannot have any blocks allcated beyond the first. If
393 * the first block is allocated already, the new size must be greater
394 * than the current block size. If these conditions are not met,
395 * ENOTSUP will be returned.
396 *
397 * Returns 0 on success, or EBUSY if there are any holds on the object
398 * contents, or ENOTSUP as described above.
399 */
400 int dmu_object_set_blocksize(objset_t *os, uint64_t object, uint64_t size,
401 int ibs, dmu_tx_t *tx);
402
403 /*
404 * Set the checksum property on a dnode. The new checksum algorithm will
405 * apply to all newly written blocks; existing blocks will not be affected.
406 */
407 void dmu_object_set_checksum(objset_t *os, uint64_t object, uint8_t checksum,
408 dmu_tx_t *tx);
409
410 /*
411 * Set the compress property on a dnode. The new compression algorithm will
412 * apply to all newly written blocks; existing blocks will not be affected.
413 */
414 void dmu_object_set_compress(objset_t *os, uint64_t object, uint8_t compress,
415 dmu_tx_t *tx);
416
417 int dmu_object_remap_indirects(objset_t *os, uint64_t object, uint64_t txg);
418
419 void
420 dmu_write_embedded(objset_t *os, uint64_t object, uint64_t offset,
421 void *data, uint8_t etype, uint8_t comp, int uncompressed_size,
422 int compressed_size, int byteorder, dmu_tx_t *tx);
423
424 /*
425 * Decide how to write a block: checksum, compression, number of copies, etc.
426 */
427 #define WP_NOFILL 0x1
428 #define WP_DMU_SYNC 0x2
429 #define WP_SPILL 0x4
430
431 void dmu_write_policy(objset_t *os, dnode_t *dn, int level, int wp,
432 struct zio_prop *zp);
433 /*
434 * The bonus data is accessed more or less like a regular buffer.
435 * You must dmu_bonus_hold() to get the buffer, which will give you a
436 * dmu_buf_t with db_offset==-1ULL, and db_size = the size of the bonus
437 * data. As with any normal buffer, you must call dmu_buf_will_dirty()
438 * before modifying it, and the
439 * object must be held in an assigned transaction before calling
440 * dmu_buf_will_dirty. You may use dmu_buf_set_user() on the bonus
441 * buffer as well. You must release your hold with dmu_buf_rele().
442 *
443 * Returns ENOENT, EIO, or 0.
444 */
445 int dmu_bonus_hold(objset_t *os, uint64_t object, void *tag, dmu_buf_t **);
446 int dmu_bonus_max(void);
447 int dmu_set_bonus(dmu_buf_t *, int, dmu_tx_t *);
448 int dmu_set_bonustype(dmu_buf_t *, dmu_object_type_t, dmu_tx_t *);
449 dmu_object_type_t dmu_get_bonustype(dmu_buf_t *);
450 int dmu_rm_spill(objset_t *, uint64_t, dmu_tx_t *);
451
452 /*
453 * Special spill buffer support used by "SA" framework
454 */
455
456 int dmu_spill_hold_by_bonus(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp);
457 int dmu_spill_hold_by_dnode(dnode_t *dn, uint32_t flags,
458 void *tag, dmu_buf_t **dbp);
459 int dmu_spill_hold_existing(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp);
460
461 /*
462 * Obtain the DMU buffer from the specified object which contains the
463 * specified offset. dmu_buf_hold() puts a "hold" on the buffer, so
464 * that it will remain in memory. You must release the hold with
465 * dmu_buf_rele(). You musn't access the dmu_buf_t after releasing your
466 * hold. You must have a hold on any dmu_buf_t* you pass to the DMU.
467 *
468 * You must call dmu_buf_read, dmu_buf_will_dirty, or dmu_buf_will_fill
469 * on the returned buffer before reading or writing the buffer's
470 * db_data. The comments for those routines describe what particular
471 * operations are valid after calling them.
472 *
473 * The object number must be a valid, allocated object number.
474 */
475 int dmu_buf_hold(objset_t *os, uint64_t object, uint64_t offset,
476 void *tag, dmu_buf_t **, int flags);
477 int dmu_buf_hold_by_dnode(dnode_t *dn, uint64_t offset,
478 void *tag, dmu_buf_t **dbp, int flags);
479
480 /*
481 * Add a reference to a dmu buffer that has already been held via
482 * dmu_buf_hold() in the current context.
483 */
484 void dmu_buf_add_ref(dmu_buf_t *db, void* tag);
485
486 /*
487 * Attempt to add a reference to a dmu buffer that is in an unknown state,
488 * using a pointer that may have been invalidated by eviction processing.
489 * The request will succeed if the passed in dbuf still represents the
490 * same os/object/blkid, is ineligible for eviction, and has at least
491 * one hold by a user other than the syncer.
492 */
493 boolean_t dmu_buf_try_add_ref(dmu_buf_t *, objset_t *os, uint64_t object,
494 uint64_t blkid, void *tag);
495
496 void dmu_buf_rele(dmu_buf_t *db, void *tag);
497 uint64_t dmu_buf_refcount(dmu_buf_t *db);
498
499 /*
500 * dmu_buf_hold_array holds the DMU buffers which contain all bytes in a
501 * range of an object. A pointer to an array of dmu_buf_t*'s is
502 * returned (in *dbpp).
503 *
504 * dmu_buf_rele_array releases the hold on an array of dmu_buf_t*'s, and
505 * frees the array. The hold on the array of buffers MUST be released
506 * with dmu_buf_rele_array. You can NOT release the hold on each buffer
507 * individually with dmu_buf_rele.
508 */
509 int dmu_buf_hold_array_by_bonus(dmu_buf_t *db, uint64_t offset,
510 uint64_t length, boolean_t read, void *tag,
511 int *numbufsp, dmu_buf_t ***dbpp);
512 void dmu_buf_rele_array(dmu_buf_t **, int numbufs, void *tag);
513
514 typedef void dmu_buf_evict_func_t(void *user_ptr);
515
516 /*
517 * A DMU buffer user object may be associated with a dbuf for the
518 * duration of its lifetime. This allows the user of a dbuf (client)
519 * to attach private data to a dbuf (e.g. in-core only data such as a
520 * dnode_children_t, zap_t, or zap_leaf_t) and be optionally notified
521 * when that dbuf has been evicted. Clients typically respond to the
522 * eviction notification by freeing their private data, thus ensuring
523 * the same lifetime for both dbuf and private data.
524 *
525 * The mapping from a dmu_buf_user_t to any client private data is the
526 * client's responsibility. All current consumers of the API with private
527 * data embed a dmu_buf_user_t as the first member of the structure for
528 * their private data. This allows conversions between the two types
529 * with a simple cast. Since the DMU buf user API never needs access
530 * to the private data, other strategies can be employed if necessary
531 * or convenient for the client (e.g. using container_of() to do the
532 * conversion for private data that cannot have the dmu_buf_user_t as
533 * its first member).
534 *
535 * Eviction callbacks are executed without the dbuf mutex held or any
536 * other type of mechanism to guarantee that the dbuf is still available.
537 * For this reason, users must assume the dbuf has already been freed
538 * and not reference the dbuf from the callback context.
539 *
540 * Users requesting "immediate eviction" are notified as soon as the dbuf
541 * is only referenced by dirty records (dirties == holds). Otherwise the
542 * notification occurs after eviction processing for the dbuf begins.
543 */
544 typedef struct dmu_buf_user {
545 /*
546 * Asynchronous user eviction callback state.
547 */
548 taskq_ent_t dbu_tqent;
549
550 /*
551 * This instance's eviction function pointers.
552 *
553 * dbu_evict_func_sync is called synchronously and then
554 * dbu_evict_func_async is executed asynchronously on a taskq.
555 */
556 dmu_buf_evict_func_t *dbu_evict_func_sync;
557 dmu_buf_evict_func_t *dbu_evict_func_async;
558 #ifdef ZFS_DEBUG
559 /*
560 * Pointer to user's dbuf pointer. NULL for clients that do
561 * not associate a dbuf with their user data.
562 *
563 * The dbuf pointer is cleared upon eviction so as to catch
564 * use-after-evict bugs in clients.
565 */
566 dmu_buf_t **dbu_clear_on_evict_dbufp;
567 #endif
568 } dmu_buf_user_t;
569
570 /*
571 * Initialize the given dmu_buf_user_t instance with the eviction function
572 * evict_func, to be called when the user is evicted.
573 *
574 * NOTE: This function should only be called once on a given dmu_buf_user_t.
575 * To allow enforcement of this, dbu must already be zeroed on entry.
576 */
577 /*ARGSUSED*/
578 inline void
579 dmu_buf_init_user(dmu_buf_user_t *dbu, dmu_buf_evict_func_t *evict_func_sync,
580 dmu_buf_evict_func_t *evict_func_async, dmu_buf_t **clear_on_evict_dbufp)
581 {
582 ASSERT(dbu->dbu_evict_func_sync == NULL);
583 ASSERT(dbu->dbu_evict_func_async == NULL);
584
585 /* must have at least one evict func */
586 IMPLY(evict_func_sync == NULL, evict_func_async != NULL);
587 dbu->dbu_evict_func_sync = evict_func_sync;
588 dbu->dbu_evict_func_async = evict_func_async;
589 #ifdef ZFS_DEBUG
590 dbu->dbu_clear_on_evict_dbufp = clear_on_evict_dbufp;
591 #endif
592 }
593
594 /*
595 * Attach user data to a dbuf and mark it for normal (when the dbuf's
596 * data is cleared or its reference count goes to zero) eviction processing.
597 *
598 * Returns NULL on success, or the existing user if another user currently
599 * owns the buffer.
600 */
601 void *dmu_buf_set_user(dmu_buf_t *db, dmu_buf_user_t *user);
602
603 /*
604 * Attach user data to a dbuf and mark it for immediate (its dirty and
605 * reference counts are equal) eviction processing.
606 *
607 * Returns NULL on success, or the existing user if another user currently
608 * owns the buffer.
609 */
610 void *dmu_buf_set_user_ie(dmu_buf_t *db, dmu_buf_user_t *user);
611
612 /*
613 * Replace the current user of a dbuf.
614 *
615 * If given the current user of a dbuf, replaces the dbuf's user with
616 * "new_user" and returns the user data pointer that was replaced.
617 * Otherwise returns the current, and unmodified, dbuf user pointer.
618 */
619 void *dmu_buf_replace_user(dmu_buf_t *db,
620 dmu_buf_user_t *old_user, dmu_buf_user_t *new_user);
621
622 /*
623 * Remove the specified user data for a DMU buffer.
624 *
625 * Returns the user that was removed on success, or the current user if
626 * another user currently owns the buffer.
627 */
628 void *dmu_buf_remove_user(dmu_buf_t *db, dmu_buf_user_t *user);
629
630 /*
631 * Returns the user data (dmu_buf_user_t *) associated with this dbuf.
632 */
633 void *dmu_buf_get_user(dmu_buf_t *db);
634
635 objset_t *dmu_buf_get_objset(dmu_buf_t *db);
636 dnode_t *dmu_buf_dnode_enter(dmu_buf_t *db);
637 void dmu_buf_dnode_exit(dmu_buf_t *db);
638
639 /* Block until any in-progress dmu buf user evictions complete. */
640 void dmu_buf_user_evict_wait(void);
641
642 /*
643 * Returns the blkptr associated with this dbuf, or NULL if not set.
644 */
645 struct blkptr *dmu_buf_get_blkptr(dmu_buf_t *db);
646
647 /*
648 * Indicate that you are going to modify the buffer's data (db_data).
649 *
650 * The transaction (tx) must be assigned to a txg (ie. you've called
651 * dmu_tx_assign()). The buffer's object must be held in the tx
652 * (ie. you've called dmu_tx_hold_object(tx, db->db_object)).
653 */
654 void dmu_buf_will_dirty(dmu_buf_t *db, dmu_tx_t *tx);
655
656 /*
657 * You must create a transaction, then hold the objects which you will
658 * (or might) modify as part of this transaction. Then you must assign
659 * the transaction to a transaction group. Once the transaction has
660 * been assigned, you can modify buffers which belong to held objects as
661 * part of this transaction. You can't modify buffers before the
662 * transaction has been assigned; you can't modify buffers which don't
663 * belong to objects which this transaction holds; you can't hold
664 * objects once the transaction has been assigned. You may hold an
665 * object which you are going to free (with dmu_object_free()), but you
666 * don't have to.
667 *
668 * You can abort the transaction before it has been assigned.
669 *
670 * Note that you may hold buffers (with dmu_buf_hold) at any time,
671 * regardless of transaction state.
672 */
673
674 #define DMU_NEW_OBJECT (-1ULL)
675 #define DMU_OBJECT_END (-1ULL)
676
677 dmu_tx_t *dmu_tx_create(objset_t *os);
678 void dmu_tx_hold_write(dmu_tx_t *tx, uint64_t object, uint64_t off, int len);
679 void dmu_tx_hold_write_by_dnode(dmu_tx_t *tx, dnode_t *dn, uint64_t off,
680 int len);
681 void dmu_tx_hold_free(dmu_tx_t *tx, uint64_t object, uint64_t off,
682 uint64_t len);
683 void dmu_tx_hold_free_by_dnode(dmu_tx_t *tx, dnode_t *dn, uint64_t off,
684 uint64_t len);
685 void dmu_tx_hold_remap_l1indirect(dmu_tx_t *tx, uint64_t object);
686 void dmu_tx_hold_zap(dmu_tx_t *tx, uint64_t object, int add, const char *name);
687 void dmu_tx_hold_zap_by_dnode(dmu_tx_t *tx, dnode_t *dn, int add,
688 const char *name);
689 void dmu_tx_hold_bonus(dmu_tx_t *tx, uint64_t object);
690 void dmu_tx_hold_bonus_by_dnode(dmu_tx_t *tx, dnode_t *dn);
691 void dmu_tx_hold_spill(dmu_tx_t *tx, uint64_t object);
692 void dmu_tx_hold_sa(dmu_tx_t *tx, struct sa_handle *hdl, boolean_t may_grow);
693 void dmu_tx_hold_sa_create(dmu_tx_t *tx, int total_size);
694 void dmu_tx_abort(dmu_tx_t *tx);
695 int dmu_tx_assign(dmu_tx_t *tx, uint64_t txg_how);
696 void dmu_tx_wait(dmu_tx_t *tx);
697 void dmu_tx_commit(dmu_tx_t *tx);
698 void dmu_tx_mark_netfree(dmu_tx_t *tx);
699
700 /*
701 * To register a commit callback, dmu_tx_callback_register() must be called.
702 *
703 * dcb_data is a pointer to caller private data that is passed on as a
704 * callback parameter. The caller is responsible for properly allocating and
705 * freeing it.
706 *
707 * When registering a callback, the transaction must be already created, but
708 * it cannot be committed or aborted. It can be assigned to a txg or not.
709 *
710 * The callback will be called after the transaction has been safely written
711 * to stable storage and will also be called if the dmu_tx is aborted.
712 * If there is any error which prevents the transaction from being committed to
713 * disk, the callback will be called with a value of error != 0.
714 */
715 typedef void dmu_tx_callback_func_t(void *dcb_data, int error);
716
717 void dmu_tx_callback_register(dmu_tx_t *tx, dmu_tx_callback_func_t *dcb_func,
718 void *dcb_data);
719
720 /*
721 * Free up the data blocks for a defined range of a file. If size is
722 * -1, the range from offset to end-of-file is freed.
723 */
724 int dmu_free_range(objset_t *os, uint64_t object, uint64_t offset,
725 uint64_t size, dmu_tx_t *tx);
726 int dmu_free_long_range(objset_t *os, uint64_t object, uint64_t offset,
727 uint64_t size);
728 int dmu_free_long_object(objset_t *os, uint64_t object);
729
730 /*
731 * Convenience functions.
732 *
733 * Canfail routines will return 0 on success, or an errno if there is a
734 * nonrecoverable I/O error.
735 */
736 #define DMU_READ_PREFETCH 0 /* prefetch */
737 #define DMU_READ_NO_PREFETCH 1 /* don't prefetch */
738 int dmu_read(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
739 void *buf, uint32_t flags);
740 int dmu_read_by_dnode(dnode_t *dn, uint64_t offset, uint64_t size, void *buf,
741 uint32_t flags);
742 void dmu_write(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
743 const void *buf, dmu_tx_t *tx);
744 void dmu_write_by_dnode(dnode_t *dn, uint64_t offset, uint64_t size,
745 const void *buf, dmu_tx_t *tx);
746 void dmu_prealloc(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
747 dmu_tx_t *tx);
748 int dmu_read_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size);
749 int dmu_read_uio_dbuf(dmu_buf_t *zdb, struct uio *uio, uint64_t size);
750 int dmu_write_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size,
751 dmu_tx_t *tx);
752 int dmu_write_uio_dbuf(dmu_buf_t *zdb, struct uio *uio, uint64_t size,
753 dmu_tx_t *tx);
754 int dmu_write_pages(objset_t *os, uint64_t object, uint64_t offset,
755 uint64_t size, struct page *pp, dmu_tx_t *tx);
756 struct arc_buf *dmu_request_arcbuf(dmu_buf_t *handle, int size);
757 void dmu_return_arcbuf(struct arc_buf *buf);
758 void dmu_assign_arcbuf(dmu_buf_t *handle, uint64_t offset, struct arc_buf *buf,
759 dmu_tx_t *tx);
760 int dmu_xuio_init(struct xuio *uio, int niov);
761 void dmu_xuio_fini(struct xuio *uio);
762 int dmu_xuio_add(struct xuio *uio, struct arc_buf *abuf, offset_t off,
763 size_t n);
764 int dmu_xuio_cnt(struct xuio *uio);
765 struct arc_buf *dmu_xuio_arcbuf(struct xuio *uio, int i);
766 void dmu_xuio_clear(struct xuio *uio, int i);
767 void xuio_stat_wbuf_copied(void);
768 void xuio_stat_wbuf_nocopy(void);
769
770 extern boolean_t zfs_prefetch_disable;
771 extern int zfs_max_recordsize;
772
773 /*
774 * Asynchronously try to read in the data.
775 */
776 void dmu_prefetch(objset_t *os, uint64_t object, int64_t level, uint64_t offset,
777 uint64_t len, enum zio_priority pri);
778
779 typedef struct dmu_object_info {
780 /* All sizes are in bytes unless otherwise indicated. */
781 uint32_t doi_data_block_size;
782 uint32_t doi_metadata_block_size;
783 dmu_object_type_t doi_type;
784 dmu_object_type_t doi_bonus_type;
785 uint64_t doi_bonus_size;
786 uint8_t doi_indirection; /* 2 = dnode->indirect->data */
787 uint8_t doi_checksum;
788 uint8_t doi_compress;
789 uint8_t doi_nblkptr;
790 uint8_t doi_pad[4];
791 uint64_t doi_physical_blocks_512; /* data + metadata, 512b blks */
792 uint64_t doi_max_offset;
793 uint64_t doi_fill_count; /* number of non-empty blocks */
794 } dmu_object_info_t;
795
796 typedef void arc_byteswap_func_t(void *buf, size_t size);
797
798 typedef struct dmu_object_type_info {
799 dmu_object_byteswap_t ot_byteswap;
800 boolean_t ot_metadata;
801 char *ot_name;
802 } dmu_object_type_info_t;
803
804 typedef struct dmu_object_byteswap_info {
805 arc_byteswap_func_t *ob_func;
806 char *ob_name;
807 } dmu_object_byteswap_info_t;
808
809 extern const dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES];
810 extern const dmu_object_byteswap_info_t dmu_ot_byteswap[DMU_BSWAP_NUMFUNCS];
811
812 /*
813 * Get information on a DMU object.
814 *
815 * Return 0 on success or ENOENT if object is not allocated.
816 *
817 * If doi is NULL, just indicates whether the object exists.
818 */
819 int dmu_object_info(objset_t *os, uint64_t object, dmu_object_info_t *doi);
820 /* Like dmu_object_info, but faster if you have a held dnode in hand. */
821 void dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi);
822 /* Like dmu_object_info, but faster if you have a held dbuf in hand. */
823 void dmu_object_info_from_db(dmu_buf_t *db, dmu_object_info_t *doi);
824 /*
825 * Like dmu_object_info_from_db, but faster still when you only care about
826 * the size. This is specifically optimized for zfs_getattr().
827 */
828 void dmu_object_size_from_db(dmu_buf_t *db, uint32_t *blksize,
829 u_longlong_t *nblk512);
830
831 typedef struct dmu_objset_stats {
832 uint64_t dds_num_clones; /* number of clones of this */
833 uint64_t dds_creation_txg;
834 uint64_t dds_guid;
835 dmu_objset_type_t dds_type;
836 uint8_t dds_is_snapshot;
837 uint8_t dds_inconsistent;
838 char dds_origin[ZFS_MAX_DATASET_NAME_LEN];
839 } dmu_objset_stats_t;
840
841 /*
842 * Get stats on a dataset.
843 */
844 void dmu_objset_fast_stat(objset_t *os, dmu_objset_stats_t *stat);
845
846 /*
847 * Add entries to the nvlist for all the objset's properties. See
848 * zfs_prop_table[] and zfs(1m) for details on the properties.
849 */
850 void dmu_objset_stats(objset_t *os, struct nvlist *nv);
851
852 /*
853 * Get the space usage statistics for statvfs().
854 *
855 * refdbytes is the amount of space "referenced" by this objset.
856 * availbytes is the amount of space available to this objset, taking
857 * into account quotas & reservations, assuming that no other objsets
858 * use the space first. These values correspond to the 'referenced' and
859 * 'available' properties, described in the zfs(1m) manpage.
860 *
861 * usedobjs and availobjs are the number of objects currently allocated,
862 * and available.
863 */
864 void dmu_objset_space(objset_t *os, uint64_t *refdbytesp, uint64_t *availbytesp,
865 uint64_t *usedobjsp, uint64_t *availobjsp);
866
867 /*
868 * The fsid_guid is a 56-bit ID that can change to avoid collisions.
869 * (Contrast with the ds_guid which is a 64-bit ID that will never
870 * change, so there is a small probability that it will collide.)
871 */
872 uint64_t dmu_objset_fsid_guid(objset_t *os);
873
874 /*
875 * Get the [cm]time for an objset's snapshot dir
876 */
877 timestruc_t dmu_objset_snap_cmtime(objset_t *os);
878
879 int dmu_objset_is_snapshot(objset_t *os);
880
881 extern struct spa *dmu_objset_spa(objset_t *os);
882 extern struct zilog *dmu_objset_zil(objset_t *os);
883 extern struct dsl_pool *dmu_objset_pool(objset_t *os);
884 extern struct dsl_dataset *dmu_objset_ds(objset_t *os);
885 extern void dmu_objset_name(objset_t *os, char *buf);
886 extern dmu_objset_type_t dmu_objset_type(objset_t *os);
887 extern uint64_t dmu_objset_id(objset_t *os);
888 extern zfs_sync_type_t dmu_objset_syncprop(objset_t *os);
889 extern zfs_logbias_op_t dmu_objset_logbias(objset_t *os);
890 extern int dmu_snapshot_list_next(objset_t *os, int namelen, char *name,
891 uint64_t *id, uint64_t *offp, boolean_t *case_conflict);
892 extern int dmu_snapshot_realname(objset_t *os, char *name, char *real,
893 int maxlen, boolean_t *conflict);
894 extern int dmu_dir_list_next(objset_t *os, int namelen, char *name,
895 uint64_t *idp, uint64_t *offp);
896
897 typedef int objset_used_cb_t(dmu_object_type_t bonustype,
898 void *bonus, uint64_t *userp, uint64_t *groupp);
899 extern void dmu_objset_register_type(dmu_objset_type_t ost,
900 objset_used_cb_t *cb);
901 extern void dmu_objset_set_user(objset_t *os, void *user_ptr);
902 extern void *dmu_objset_get_user(objset_t *os);
903
904 /*
905 * Return the txg number for the given assigned transaction.
906 */
907 uint64_t dmu_tx_get_txg(dmu_tx_t *tx);
908
909 /*
910 * Synchronous write.
911 * If a parent zio is provided this function initiates a write on the
912 * provided buffer as a child of the parent zio.
913 * In the absence of a parent zio, the write is completed synchronously.
914 * At write completion, blk is filled with the bp of the written block.
915 * Note that while the data covered by this function will be on stable
916 * storage when the write completes this new data does not become a
917 * permanent part of the file until the associated transaction commits.
918 */
919
920 /*
921 * {zfs,zvol,ztest}_get_done() args
922 */
923 typedef struct zgd {
924 struct lwb *zgd_lwb;
925 struct blkptr *zgd_bp;
926 dmu_buf_t *zgd_db;
927 struct rl *zgd_rl;
928 void *zgd_private;
929 } zgd_t;
930
931 typedef void dmu_sync_cb_t(zgd_t *arg, int error);
932 int dmu_sync(struct zio *zio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd);
933
934 /*
935 * Find the next hole or data block in file starting at *off
936 * Return found offset in *off. Return ESRCH for end of file.
937 */
938 int dmu_offset_next(objset_t *os, uint64_t object, boolean_t hole,
939 uint64_t *off);
940
941 /*
942 * Check if a DMU object has any dirty blocks. If so, sync out
943 * all pending transaction groups. Otherwise, this function
944 * does not alter DMU state. This could be improved to only sync
945 * out the necessary transaction groups for this particular
946 * object.
947 */
948 int dmu_object_wait_synced(objset_t *os, uint64_t object);
949
950 /*
951 * Initial setup and final teardown.
952 */
953 extern void dmu_init(void);
954 extern void dmu_fini(void);
955
956 typedef void (*dmu_traverse_cb_t)(objset_t *os, void *arg, struct blkptr *bp,
957 uint64_t object, uint64_t offset, int len);
958 void dmu_traverse_objset(objset_t *os, uint64_t txg_start,
959 dmu_traverse_cb_t cb, void *arg);
960
961 int dmu_diff(const char *tosnap_name, const char *fromsnap_name,
962 struct vnode *vp, offset_t *offp);
963
964 /* CRC64 table */
965 #define ZFS_CRC64_POLY 0xC96C5795D7870F42ULL /* ECMA-182, reflected form */
966 extern uint64_t zfs_crc64_table[256];
967
968 extern int zfs_mdcomp_disable;
969
970 #ifdef __cplusplus
971 }
972 #endif
973
974 #endif /* _SYS_DMU_H */