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/inttypes.h>
49#include <sys/cred.h>
50#include <sys/fs/zfs.h>
51#include <sys/zio_priority.h>
52
53#ifdef __cplusplus
54extern "C" {
55#endif
56
57struct uio;
58struct xuio;
59struct page;
60struct vnode;
61struct spa;
62struct zilog;
63struct zio;
64struct blkptr;
65struct zap_cursor;
66struct dsl_dataset;
67struct dsl_pool;
68struct dnode;
69struct drr_begin;
70struct drr_end;
71struct zbookmark_phys;
72struct spa;
73struct nvlist;
74struct arc_buf;
75struct zio_prop;
76struct sa_handle;
77struct file;
78
79typedef struct objset objset_t;
80typedef struct dmu_tx dmu_tx_t;
81typedef struct dsl_dir dsl_dir_t;
82typedef struct dnode dnode_t;
83
84typedef 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
139typedef 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
234typedef enum txg_how {
235 TXG_WAIT = 1,
236 TXG_NOWAIT,
237 TXG_WAITED,
238} txg_how_t;
239
240void byteswap_uint64_array(void *buf, size_t size);
241void byteswap_uint32_array(void *buf, size_t size);
242void byteswap_uint16_array(void *buf, size_t size);
243void byteswap_uint8_array(void *buf, size_t size);
244void zap_byteswap(void *buf, size_t size);
245void zfs_oldacl_byteswap(void *buf, size_t size);
246void zfs_acl_byteswap(void *buf, size_t size);
247void zfs_znode_byteswap(void *buf, size_t size);
248
249#define DS_FIND_SNAPSHOTS (1<<0)
250#define DS_FIND_CHILDREN (1<<1)
251#define DS_FIND_SERIALIZE (1<<2)
252
253/*
254 * The maximum number of bytes that can be accessed as part of one
255 * operation, including metadata.
256 */
257#define DMU_MAX_ACCESS (32 * 1024 * 1024) /* 32MB */
258#define DMU_MAX_DELETEBLKCNT (20480) /* ~5MB of indirect blocks */
259
260#define DMU_USERUSED_OBJECT (-1ULL)
261#define DMU_GROUPUSED_OBJECT (-2ULL)
262
263/*
264 * artificial blkids for bonus buffer and spill blocks
265 */
266#define DMU_BONUS_BLKID (-1ULL)
267#define DMU_SPILL_BLKID (-2ULL)
268/*
269 * Public routines to create, destroy, open, and close objsets.
270 */
271int dmu_objset_hold(const char *name, void *tag, objset_t **osp);
272int dmu_objset_own(const char *name, dmu_objset_type_t type,
273 boolean_t readonly, void *tag, objset_t **osp);
274void dmu_objset_rele(objset_t *os, void *tag);
275void dmu_objset_disown(objset_t *os, void *tag);
276int dmu_objset_open_ds(struct dsl_dataset *ds, objset_t **osp);
277
278void dmu_objset_evict_dbufs(objset_t *os);
279int dmu_objset_create(const char *name, dmu_objset_type_t type, uint64_t flags,
280 void (*func)(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx), void *arg);
281int dmu_get_recursive_snaps_nvl(char *fsname, const char *snapname,
282 struct nvlist *snaps);
283int dmu_objset_clone(const char *name, const char *origin);
284int dsl_destroy_snapshots_nvl(struct nvlist *snaps, boolean_t defer,
285 struct nvlist *errlist);
286int dmu_objset_snapshot_one(const char *fsname, const char *snapname);
287int dmu_objset_snapshot_tmp(const char *, const char *, int);
288int dmu_objset_find(char *name, int func(const char *, void *), void *arg,
289 int flags);
290void dmu_objset_byteswap(void *buf, size_t size);
291int dsl_dataset_rename_snapshot(const char *fsname,
292 const char *oldsnapname, const char *newsnapname, boolean_t recursive);
293
294typedef struct dmu_buf {
295 uint64_t db_object; /* object that this buffer is part of */
296 uint64_t db_offset; /* byte offset in this object */
297 uint64_t db_size; /* size of buffer in bytes */
298 void *db_data; /* data in buffer */
299} dmu_buf_t;
300
301/*
302 * The names of zap entries in the DIRECTORY_OBJECT of the MOS.
303 */
304#define DMU_POOL_DIRECTORY_OBJECT 1
305#define DMU_POOL_CONFIG "config"
306#define DMU_POOL_FEATURES_FOR_WRITE "features_for_write"
307#define DMU_POOL_FEATURES_FOR_READ "features_for_read"
308#define DMU_POOL_FEATURE_DESCRIPTIONS "feature_descriptions"
309#define DMU_POOL_FEATURE_ENABLED_TXG "feature_enabled_txg"
310#define DMU_POOL_ROOT_DATASET "root_dataset"
311#define DMU_POOL_SYNC_BPOBJ "sync_bplist"
312#define DMU_POOL_ERRLOG_SCRUB "errlog_scrub"
313#define DMU_POOL_ERRLOG_LAST "errlog_last"
314#define DMU_POOL_SPARES "spares"
315#define DMU_POOL_DEFLATE "deflate"
316#define DMU_POOL_HISTORY "history"
317#define DMU_POOL_PROPS "pool_props"
318#define DMU_POOL_L2CACHE "l2cache"
319#define DMU_POOL_TMP_USERREFS "tmp_userrefs"
320#define DMU_POOL_DDT "DDT-%s-%s-%s"
321#define DMU_POOL_DDT_STATS "DDT-statistics"
322#define DMU_POOL_CREATION_VERSION "creation_version"
323#define DMU_POOL_SCAN "scan"
324#define DMU_POOL_FREE_BPOBJ "free_bpobj"
325#define DMU_POOL_BPTREE_OBJ "bptree_obj"
326#define DMU_POOL_EMPTY_BPOBJ "empty_bpobj"
327#define DMU_POOL_CHECKSUM_SALT "org.illumos:checksum_salt"
328#define DMU_POOL_VDEV_ZAP_MAP "com.delphix:vdev_zap_map"
329
330/*
331 * Allocate an object from this objset. The range of object numbers
332 * available is (0, DN_MAX_OBJECT). Object 0 is the meta-dnode.
333 *
334 * The transaction must be assigned to a txg. The newly allocated
335 * object will be "held" in the transaction (ie. you can modify the
336 * newly allocated object in this transaction).
337 *
338 * dmu_object_alloc() chooses an object and returns it in *objectp.
339 *
340 * dmu_object_claim() allocates a specific object number. If that
341 * number is already allocated, it fails and returns EEXIST.
342 *
343 * Return 0 on success, or ENOSPC or EEXIST as specified above.
344 */
345uint64_t dmu_object_alloc(objset_t *os, dmu_object_type_t ot,
346 int blocksize, dmu_object_type_t bonus_type, int bonus_len, dmu_tx_t *tx);
347int dmu_object_claim(objset_t *os, uint64_t object, dmu_object_type_t ot,
348 int blocksize, dmu_object_type_t bonus_type, int bonus_len, dmu_tx_t *tx);
349int dmu_object_reclaim(objset_t *os, uint64_t object, dmu_object_type_t ot,
350 int blocksize, dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *txp);
351
352/*
353 * Free an object from this objset.
354 *
355 * The object's data will be freed as well (ie. you don't need to call
356 * dmu_free(object, 0, -1, tx)).
357 *
358 * The object need not be held in the transaction.
359 *
360 * If there are any holds on this object's buffers (via dmu_buf_hold()),
361 * or tx holds on the object (via dmu_tx_hold_object()), you can not
362 * free it; it fails and returns EBUSY.
363 *
364 * If the object is not allocated, it fails and returns ENOENT.
365 *
366 * Return 0 on success, or EBUSY or ENOENT as specified above.
367 */
368int dmu_object_free(objset_t *os, uint64_t object, dmu_tx_t *tx);
369
370/*
371 * Find the next allocated or free object.
372 *
373 * The objectp parameter is in-out. It will be updated to be the next
374 * object which is allocated. Ignore objects which have not been
375 * modified since txg.
376 *
377 * XXX Can only be called on a objset with no dirty data.
378 *
379 * Returns 0 on success, or ENOENT if there are no more objects.
380 */
381int dmu_object_next(objset_t *os, uint64_t *objectp,
382 boolean_t hole, uint64_t txg);
383
384/*
385 * Set the data blocksize for an object.
386 *
387 * The object cannot have any blocks allcated beyond the first. If
388 * the first block is allocated already, the new size must be greater
389 * than the current block size. If these conditions are not met,
390 * ENOTSUP will be returned.
391 *
392 * Returns 0 on success, or EBUSY if there are any holds on the object
393 * contents, or ENOTSUP as described above.
394 */
395int dmu_object_set_blocksize(objset_t *os, uint64_t object, uint64_t size,
396 int ibs, dmu_tx_t *tx);
397
398/*
399 * Set the checksum property on a dnode. The new checksum algorithm will
400 * apply to all newly written blocks; existing blocks will not be affected.
401 */
402void dmu_object_set_checksum(objset_t *os, uint64_t object, uint8_t checksum,
403 dmu_tx_t *tx);
404
405/*
406 * Set the compress property on a dnode. The new compression algorithm will
407 * apply to all newly written blocks; existing blocks will not be affected.
408 */
409void dmu_object_set_compress(objset_t *os, uint64_t object, uint8_t compress,
410 dmu_tx_t *tx);
411
412void
413dmu_write_embedded(objset_t *os, uint64_t object, uint64_t offset,
414 void *data, uint8_t etype, uint8_t comp, int uncompressed_size,
415 int compressed_size, int byteorder, dmu_tx_t *tx);
416
417/*
418 * Decide how to write a block: checksum, compression, number of copies, etc.
419 */
420#define WP_NOFILL 0x1
421#define WP_DMU_SYNC 0x2
422#define WP_SPILL 0x4
423
424void dmu_write_policy(objset_t *os, dnode_t *dn, int level, int wp,
425 struct zio_prop *zp);
426/*
427 * The bonus data is accessed more or less like a regular buffer.
428 * You must dmu_bonus_hold() to get the buffer, which will give you a
429 * dmu_buf_t with db_offset==-1ULL, and db_size = the size of the bonus
430 * data. As with any normal buffer, you must call dmu_buf_read() to
431 * read db_data, dmu_buf_will_dirty() before modifying it, and the
432 * object must be held in an assigned transaction before calling
433 * dmu_buf_will_dirty. You may use dmu_buf_set_user() on the bonus
434 * buffer as well. You must release your hold with dmu_buf_rele().
435 *
436 * Returns ENOENT, EIO, or 0.
437 */
438int dmu_bonus_hold(objset_t *os, uint64_t object, void *tag, dmu_buf_t **);
439int dmu_bonus_max(void);
440int dmu_set_bonus(dmu_buf_t *, int, dmu_tx_t *);
441int dmu_set_bonustype(dmu_buf_t *, dmu_object_type_t, dmu_tx_t *);
442dmu_object_type_t dmu_get_bonustype(dmu_buf_t *);
443int dmu_rm_spill(objset_t *, uint64_t, dmu_tx_t *);
444
445/*
446 * Special spill buffer support used by "SA" framework
447 */
448
449int dmu_spill_hold_by_bonus(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp);
450int dmu_spill_hold_by_dnode(dnode_t *dn, uint32_t flags,
451 void *tag, dmu_buf_t **dbp);
452int dmu_spill_hold_existing(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp);
453
454/*
455 * Obtain the DMU buffer from the specified object which contains the
456 * specified offset. dmu_buf_hold() puts a "hold" on the buffer, so
457 * that it will remain in memory. You must release the hold with
458 * dmu_buf_rele(). You musn't access the dmu_buf_t after releasing your
459 * hold. You must have a hold on any dmu_buf_t* you pass to the DMU.
460 *
461 * You must call dmu_buf_read, dmu_buf_will_dirty, or dmu_buf_will_fill
462 * on the returned buffer before reading or writing the buffer's
463 * db_data. The comments for those routines describe what particular
464 * operations are valid after calling them.
465 *
466 * The object number must be a valid, allocated object number.
467 */
468int dmu_buf_hold(objset_t *os, uint64_t object, uint64_t offset,
469 void *tag, dmu_buf_t **, int flags);
470int dmu_buf_hold_by_dnode(dnode_t *dn, uint64_t offset,
471 void *tag, dmu_buf_t **dbp, int flags);
472
473/*
474 * Add a reference to a dmu buffer that has already been held via
475 * dmu_buf_hold() in the current context.
476 */
477void dmu_buf_add_ref(dmu_buf_t *db, void* tag);
478
479/*
480 * Attempt to add a reference to a dmu buffer that is in an unknown state,
481 * using a pointer that may have been invalidated by eviction processing.
482 * The request will succeed if the passed in dbuf still represents the
483 * same os/object/blkid, is ineligible for eviction, and has at least
484 * one hold by a user other than the syncer.
485 */
486boolean_t dmu_buf_try_add_ref(dmu_buf_t *, objset_t *os, uint64_t object,
487 uint64_t blkid, void *tag);
488
489void dmu_buf_rele(dmu_buf_t *db, void *tag);
490uint64_t dmu_buf_refcount(dmu_buf_t *db);
491
492/*
493 * dmu_buf_hold_array holds the DMU buffers which contain all bytes in a
494 * range of an object. A pointer to an array of dmu_buf_t*'s is
495 * returned (in *dbpp).
496 *
497 * dmu_buf_rele_array releases the hold on an array of dmu_buf_t*'s, and
498 * frees the array. The hold on the array of buffers MUST be released
499 * with dmu_buf_rele_array. You can NOT release the hold on each buffer
500 * individually with dmu_buf_rele.
501 */
502int dmu_buf_hold_array_by_bonus(dmu_buf_t *db, uint64_t offset,
503 uint64_t length, boolean_t read, void *tag,
504 int *numbufsp, dmu_buf_t ***dbpp);
505void dmu_buf_rele_array(dmu_buf_t **, int numbufs, void *tag);
506
507typedef void dmu_buf_evict_func_t(void *user_ptr);
508
509/*
510 * A DMU buffer user object may be associated with a dbuf for the
511 * duration of its lifetime. This allows the user of a dbuf (client)
512 * to attach private data to a dbuf (e.g. in-core only data such as a
513 * dnode_children_t, zap_t, or zap_leaf_t) and be optionally notified
514 * when that dbuf has been evicted. Clients typically respond to the
515 * eviction notification by freeing their private data, thus ensuring
516 * the same lifetime for both dbuf and private data.
517 *
518 * The mapping from a dmu_buf_user_t to any client private data is the
519 * client's responsibility. All current consumers of the API with private
520 * data embed a dmu_buf_user_t as the first member of the structure for
521 * their private data. This allows conversions between the two types
522 * with a simple cast. Since the DMU buf user API never needs access
523 * to the private data, other strategies can be employed if necessary
524 * or convenient for the client (e.g. using container_of() to do the
525 * conversion for private data that cannot have the dmu_buf_user_t as
526 * its first member).
527 *
528 * Eviction callbacks are executed without the dbuf mutex held or any
529 * other type of mechanism to guarantee that the dbuf is still available.
530 * For this reason, users must assume the dbuf has already been freed
531 * and not reference the dbuf from the callback context.
532 *
533 * Users requesting "immediate eviction" are notified as soon as the dbuf
534 * is only referenced by dirty records (dirties == holds). Otherwise the
535 * notification occurs after eviction processing for the dbuf begins.
536 */
537typedef struct dmu_buf_user {
538 /*
539 * Asynchronous user eviction callback state.
540 */
541 taskq_ent_t dbu_tqent;
542
543 /*
544 * This instance's eviction function pointers.
545 *
546 * dbu_evict_func_sync is called synchronously and then
547 * dbu_evict_func_async is executed asynchronously on a taskq.
548 */
549 dmu_buf_evict_func_t *dbu_evict_func_sync;
550 dmu_buf_evict_func_t *dbu_evict_func_async;
551#ifdef ZFS_DEBUG
552 /*
553 * Pointer to user's dbuf pointer. NULL for clients that do
554 * not associate a dbuf with their user data.
555 *
556 * The dbuf pointer is cleared upon eviction so as to catch
557 * use-after-evict bugs in clients.
558 */
559 dmu_buf_t **dbu_clear_on_evict_dbufp;
560#endif
561} dmu_buf_user_t;
562
563/*
564 * Initialize the given dmu_buf_user_t instance with the eviction function
565 * evict_func, to be called when the user is evicted.
566 *
567 * NOTE: This function should only be called once on a given dmu_buf_user_t.
568 * To allow enforcement of this, dbu must already be zeroed on entry.
569 */
570#ifdef __lint
571/* Very ugly, but it beats issuing suppression directives in many Makefiles. */
572extern void
573dmu_buf_init_user(dmu_buf_user_t *dbu, dmu_buf_evict_func_t *evict_func,
574 dmu_buf_evict_func_t *evict_func_async, dmu_buf_t **clear_on_evict_dbufp);
575#else /* __lint */
576inline void
577dmu_buf_init_user(dmu_buf_user_t *dbu, dmu_buf_evict_func_t *evict_func_sync,
578 dmu_buf_evict_func_t *evict_func_async, dmu_buf_t **clear_on_evict_dbufp)
579{
580 ASSERT(dbu->dbu_evict_func_sync == NULL);
581 ASSERT(dbu->dbu_evict_func_async == NULL);
582
583 /* must have at least one evict func */
584 IMPLY(evict_func_sync == NULL, evict_func_async != NULL);
585 dbu->dbu_evict_func_sync = evict_func_sync;
586 dbu->dbu_evict_func_async = evict_func_async;
587#ifdef ZFS_DEBUG
588 dbu->dbu_clear_on_evict_dbufp = clear_on_evict_dbufp;
589#endif
590}
591#endif /* __lint */
592
593/*
594 * Attach user data to a dbuf and mark it for normal (when the dbuf's
595 * data is cleared or its reference count goes to zero) eviction processing.
596 *
597 * Returns NULL on success, or the existing user if another user currently
598 * owns the buffer.
599 */
600void *dmu_buf_set_user(dmu_buf_t *db, dmu_buf_user_t *user);
601
602/*
603 * Attach user data to a dbuf and mark it for immediate (its dirty and
604 * reference counts are equal) eviction processing.
605 *
606 * Returns NULL on success, or the existing user if another user currently
607 * owns the buffer.
608 */
609void *dmu_buf_set_user_ie(dmu_buf_t *db, dmu_buf_user_t *user);
610
611/*
612 * Replace the current user of a dbuf.
613 *
614 * If given the current user of a dbuf, replaces the dbuf's user with
615 * "new_user" and returns the user data pointer that was replaced.
616 * Otherwise returns the current, and unmodified, dbuf user pointer.
617 */
618void *dmu_buf_replace_user(dmu_buf_t *db,
619 dmu_buf_user_t *old_user, dmu_buf_user_t *new_user);
620
621/*
622 * Remove the specified user data for a DMU buffer.
623 *
624 * Returns the user that was removed on success, or the current user if
625 * another user currently owns the buffer.
626 */
627void *dmu_buf_remove_user(dmu_buf_t *db, dmu_buf_user_t *user);
628
629/*
630 * Returns the user data (dmu_buf_user_t *) associated with this dbuf.
631 */
632void *dmu_buf_get_user(dmu_buf_t *db);
633
634objset_t *dmu_buf_get_objset(dmu_buf_t *db);
635dnode_t *dmu_buf_dnode_enter(dmu_buf_t *db);
636void dmu_buf_dnode_exit(dmu_buf_t *db);
637
638/* Block until any in-progress dmu buf user evictions complete. */
639void dmu_buf_user_evict_wait(void);
640
641/*
642 * Returns the blkptr associated with this dbuf, or NULL if not set.
643 */
644struct blkptr *dmu_buf_get_blkptr(dmu_buf_t *db);
645
646/*
647 * Indicate that you are going to modify the buffer's data (db_data).
648 *
649 * The transaction (tx) must be assigned to a txg (ie. you've called
650 * dmu_tx_assign()). The buffer's object must be held in the tx
651 * (ie. you've called dmu_tx_hold_object(tx, db->db_object)).
652 */
653void dmu_buf_will_dirty(dmu_buf_t *db, dmu_tx_t *tx);
654
655/*
656 * Tells if the given dbuf is freeable.
657 */
658boolean_t dmu_buf_freeable(dmu_buf_t *);
659
660/*
661 * You must create a transaction, then hold the objects which you will
662 * (or might) modify as part of this transaction. Then you must assign
663 * the transaction to a transaction group. Once the transaction has
664 * been assigned, you can modify buffers which belong to held objects as
665 * part of this transaction. You can't modify buffers before the
666 * transaction has been assigned; you can't modify buffers which don't
667 * belong to objects which this transaction holds; you can't hold
668 * objects once the transaction has been assigned. You may hold an
669 * object which you are going to free (with dmu_object_free()), but you
670 * don't have to.
671 *
672 * You can abort the transaction before it has been assigned.
673 *
674 * Note that you may hold buffers (with dmu_buf_hold) at any time,
675 * regardless of transaction state.
676 */
677
678#define DMU_NEW_OBJECT (-1ULL)
679#define DMU_OBJECT_END (-1ULL)
680
681dmu_tx_t *dmu_tx_create(objset_t *os);
682void dmu_tx_hold_write(dmu_tx_t *tx, uint64_t object, uint64_t off, int len);
683void dmu_tx_hold_free(dmu_tx_t *tx, uint64_t object, uint64_t off,
684 uint64_t len);
685void dmu_tx_hold_zap(dmu_tx_t *tx, uint64_t object, int add, const char *name);
686void dmu_tx_hold_bonus(dmu_tx_t *tx, uint64_t object);
687void dmu_tx_hold_spill(dmu_tx_t *tx, uint64_t object);
688void dmu_tx_hold_sa(dmu_tx_t *tx, struct sa_handle *hdl, boolean_t may_grow);
689void dmu_tx_hold_sa_create(dmu_tx_t *tx, int total_size);
690void dmu_tx_abort(dmu_tx_t *tx);
691int dmu_tx_assign(dmu_tx_t *tx, enum txg_how txg_how);
692void dmu_tx_wait(dmu_tx_t *tx);
693void dmu_tx_commit(dmu_tx_t *tx);
694void dmu_tx_mark_netfree(dmu_tx_t *tx);
695
696/*
697 * To register a commit callback, dmu_tx_callback_register() must be called.
698 *
699 * dcb_data is a pointer to caller private data that is passed on as a
700 * callback parameter. The caller is responsible for properly allocating and
701 * freeing it.
702 *
703 * When registering a callback, the transaction must be already created, but
704 * it cannot be committed or aborted. It can be assigned to a txg or not.
705 *
706 * The callback will be called after the transaction has been safely written
707 * to stable storage and will also be called if the dmu_tx is aborted.
708 * If there is any error which prevents the transaction from being committed to
709 * disk, the callback will be called with a value of error != 0.
710 */
711typedef void dmu_tx_callback_func_t(void *dcb_data, int error);
712
713void dmu_tx_callback_register(dmu_tx_t *tx, dmu_tx_callback_func_t *dcb_func,
714 void *dcb_data);
715
716/*
717 * Free up the data blocks for a defined range of a file. If size is
718 * -1, the range from offset to end-of-file is freed.
719 */
720int dmu_free_range(objset_t *os, uint64_t object, uint64_t offset,
721 uint64_t size, dmu_tx_t *tx);
722int dmu_free_long_range(objset_t *os, uint64_t object, uint64_t offset,
723 uint64_t size);
724int dmu_free_long_object(objset_t *os, uint64_t object);
725
726/*
727 * Convenience functions.
728 *
729 * Canfail routines will return 0 on success, or an errno if there is a
730 * nonrecoverable I/O error.
731 */
732#define DMU_READ_PREFETCH 0 /* prefetch */
733#define DMU_READ_NO_PREFETCH 1 /* don't prefetch */
734int dmu_read(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
735 void *buf, uint32_t flags);
736void dmu_write(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
737 const void *buf, dmu_tx_t *tx);
738void dmu_prealloc(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
739 dmu_tx_t *tx);
740int dmu_read_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size);
741int dmu_read_uio_dbuf(dmu_buf_t *zdb, struct uio *uio, uint64_t size);
742int dmu_write_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size,
743 dmu_tx_t *tx);
744int dmu_write_uio_dbuf(dmu_buf_t *zdb, struct uio *uio, uint64_t size,
745 dmu_tx_t *tx);
746#ifdef _KERNEL
747#ifdef illumos
748int dmu_write_pages(objset_t *os, uint64_t object, uint64_t offset,
749 uint64_t size, struct page *pp, dmu_tx_t *tx);
750#else
751int dmu_write_pages(objset_t *os, uint64_t object, uint64_t offset,
752 uint64_t size, struct vm_page **ppa, dmu_tx_t *tx);
753#endif
754#endif
755struct arc_buf *dmu_request_arcbuf(dmu_buf_t *handle, int size);
756void dmu_return_arcbuf(struct arc_buf *buf);
757void dmu_assign_arcbuf(dmu_buf_t *handle, uint64_t offset, struct arc_buf *buf,
758 dmu_tx_t *tx);
759int dmu_xuio_init(struct xuio *uio, int niov);
760void dmu_xuio_fini(struct xuio *uio);
761int dmu_xuio_add(struct xuio *uio, struct arc_buf *abuf, offset_t off,
762 size_t n);
763int dmu_xuio_cnt(struct xuio *uio);
764struct arc_buf *dmu_xuio_arcbuf(struct xuio *uio, int i);
765void dmu_xuio_clear(struct xuio *uio, int i);
766void xuio_stat_wbuf_copied();
767void xuio_stat_wbuf_nocopy();
768
769extern boolean_t zfs_prefetch_disable;
770extern int zfs_max_recordsize;
771
772/*
773 * Asynchronously try to read in the data.
774 */
775void dmu_prefetch(objset_t *os, uint64_t object, int64_t level, uint64_t offset,
776 uint64_t len, enum zio_priority pri);
777
778typedef struct dmu_object_info {
779 /* All sizes are in bytes unless otherwise indicated. */
780 uint32_t doi_data_block_size;
781 uint32_t doi_metadata_block_size;
782 dmu_object_type_t doi_type;
783 dmu_object_type_t doi_bonus_type;
784 uint64_t doi_bonus_size;
785 uint8_t doi_indirection; /* 2 = dnode->indirect->data */
786 uint8_t doi_checksum;
787 uint8_t doi_compress;
788 uint8_t doi_nblkptr;
789 uint8_t doi_pad[4];
790 uint64_t doi_physical_blocks_512; /* data + metadata, 512b blks */
791 uint64_t doi_max_offset;
792 uint64_t doi_fill_count; /* number of non-empty blocks */
793} dmu_object_info_t;
794
795typedef void arc_byteswap_func_t(void *buf, size_t size);
796
797typedef struct dmu_object_type_info {
798 dmu_object_byteswap_t ot_byteswap;
799 boolean_t ot_metadata;
800 char *ot_name;
801} dmu_object_type_info_t;
802
803typedef struct dmu_object_byteswap_info {
804 arc_byteswap_func_t *ob_func;
805 char *ob_name;
806} dmu_object_byteswap_info_t;
807
808extern const dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES];
809extern const dmu_object_byteswap_info_t dmu_ot_byteswap[DMU_BSWAP_NUMFUNCS];
810
811/*
812 * Get information on a DMU object.
813 *
814 * Return 0 on success or ENOENT if object is not allocated.
815 *
816 * If doi is NULL, just indicates whether the object exists.
817 */
818int dmu_object_info(objset_t *os, uint64_t object, dmu_object_info_t *doi);
819/* Like dmu_object_info, but faster if you have a held dnode in hand. */
820void dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi);
821/* Like dmu_object_info, but faster if you have a held dbuf in hand. */
822void dmu_object_info_from_db(dmu_buf_t *db, dmu_object_info_t *doi);
823/*
824 * Like dmu_object_info_from_db, but faster still when you only care about
825 * the size. This is specifically optimized for zfs_getattr().
826 */
827void dmu_object_size_from_db(dmu_buf_t *db, uint32_t *blksize,
828 u_longlong_t *nblk512);
829
830typedef struct dmu_objset_stats {
831 uint64_t dds_num_clones; /* number of clones of this */
832 uint64_t dds_creation_txg;
833 uint64_t dds_guid;
834 dmu_objset_type_t dds_type;
835 uint8_t dds_is_snapshot;
836 uint8_t dds_inconsistent;
837 char dds_origin[ZFS_MAX_DATASET_NAME_LEN];
838} dmu_objset_stats_t;
839
840/*
841 * Get stats on a dataset.
842 */
843void dmu_objset_fast_stat(objset_t *os, dmu_objset_stats_t *stat);
844
845/*
846 * Add entries to the nvlist for all the objset's properties. See
847 * zfs_prop_table[] and zfs(1m) for details on the properties.
848 */
849void dmu_objset_stats(objset_t *os, struct nvlist *nv);
850
851/*
852 * Get the space usage statistics for statvfs().
853 *
854 * refdbytes is the amount of space "referenced" by this objset.
855 * availbytes is the amount of space available to this objset, taking
856 * into account quotas & reservations, assuming that no other objsets
857 * use the space first. These values correspond to the 'referenced' and
858 * 'available' properties, described in the zfs(1m) manpage.
859 *
860 * usedobjs and availobjs are the number of objects currently allocated,
861 * and available.
862 */
863void dmu_objset_space(objset_t *os, uint64_t *refdbytesp, uint64_t *availbytesp,
864 uint64_t *usedobjsp, uint64_t *availobjsp);
865
866/*
867 * The fsid_guid is a 56-bit ID that can change to avoid collisions.
868 * (Contrast with the ds_guid which is a 64-bit ID that will never
869 * change, so there is a small probability that it will collide.)
870 */
871uint64_t dmu_objset_fsid_guid(objset_t *os);
872
873/*
874 * Get the [cm]time for an objset's snapshot dir
875 */
876timestruc_t dmu_objset_snap_cmtime(objset_t *os);
877
878int dmu_objset_is_snapshot(objset_t *os);
879
880extern struct spa *dmu_objset_spa(objset_t *os);
881extern struct zilog *dmu_objset_zil(objset_t *os);
882extern struct dsl_pool *dmu_objset_pool(objset_t *os);
883extern struct dsl_dataset *dmu_objset_ds(objset_t *os);
884extern void dmu_objset_name(objset_t *os, char *buf);
885extern dmu_objset_type_t dmu_objset_type(objset_t *os);
886extern uint64_t dmu_objset_id(objset_t *os);
887extern zfs_sync_type_t dmu_objset_syncprop(objset_t *os);
888extern zfs_logbias_op_t dmu_objset_logbias(objset_t *os);
889extern int dmu_snapshot_list_next(objset_t *os, int namelen, char *name,
890 uint64_t *id, uint64_t *offp, boolean_t *case_conflict);
891extern int dmu_snapshot_realname(objset_t *os, char *name, char *real,
892 int maxlen, boolean_t *conflict);
893extern int dmu_dir_list_next(objset_t *os, int namelen, char *name,
894 uint64_t *idp, uint64_t *offp);
895
896typedef int objset_used_cb_t(dmu_object_type_t bonustype,
897 void *bonus, uint64_t *userp, uint64_t *groupp);
898extern void dmu_objset_register_type(dmu_objset_type_t ost,
899 objset_used_cb_t *cb);
900extern void dmu_objset_set_user(objset_t *os, void *user_ptr);
901extern void *dmu_objset_get_user(objset_t *os);
902
903/*
904 * Return the txg number for the given assigned transaction.
905 */
906uint64_t dmu_tx_get_txg(dmu_tx_t *tx);
907
908/*
909 * Synchronous write.
910 * If a parent zio is provided this function initiates a write on the
911 * provided buffer as a child of the parent zio.
912 * In the absence of a parent zio, the write is completed synchronously.
913 * At write completion, blk is filled with the bp of the written block.
914 * Note that while the data covered by this function will be on stable
915 * storage when the write completes this new data does not become a
916 * permanent part of the file until the associated transaction commits.
917 */
918
919/*
920 * {zfs,zvol,ztest}_get_done() args
921 */
922typedef struct zgd {
923 struct zilog *zgd_zilog;
924 struct blkptr *zgd_bp;
925 dmu_buf_t *zgd_db;
926 struct rl *zgd_rl;
927 void *zgd_private;
928} zgd_t;
929
930typedef void dmu_sync_cb_t(zgd_t *arg, int error);
931int dmu_sync(struct zio *zio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd);
932
933/*
934 * Find the next hole or data block in file starting at *off
935 * Return found offset in *off. Return ESRCH for end of file.
936 */
937int dmu_offset_next(objset_t *os, uint64_t object, boolean_t hole,
938 uint64_t *off);
939
940/*
941 * Check if a DMU object has any dirty blocks. If so, sync out
942 * all pending transaction groups. Otherwise, this function
943 * does not alter DMU state. This could be improved to only sync
944 * out the necessary transaction groups for this particular
945 * object.
946 */
947int dmu_object_wait_synced(objset_t *os, uint64_t object);
948
949/*
950 * Initial setup and final teardown.
951 */
952extern void dmu_init(void);
953extern void dmu_fini(void);
954
955typedef void (*dmu_traverse_cb_t)(objset_t *os, void *arg, struct blkptr *bp,
956 uint64_t object, uint64_t offset, int len);
957void dmu_traverse_objset(objset_t *os, uint64_t txg_start,
958 dmu_traverse_cb_t cb, void *arg);
959
960#ifdef __FreeBSD__
961int dmu_diff(const char *tosnap_name, const char *fromsnap_name,
962 struct file *fp, offset_t *offp);
963#else
964int dmu_diff(const char *tosnap_name, const char *fromsnap_name,
965 struct vnode *vp, offset_t *offp);
966#endif
967
968/* CRC64 table */
969#define ZFS_CRC64_POLY 0xC96C5795D7870F42ULL /* ECMA-182, reflected form */
970extern uint64_t zfs_crc64_table[256];
971
972extern int zfs_mdcomp_disable;
973
974#ifdef __cplusplus
975}
976#endif
977
978#endif /* _SYS_DMU_H */
979