xref: /titanic_51/usr/src/uts/common/fs/zfs/sys/dmu.h (revision 8fc99e42676a23421c75e76660640f9765d693b1)
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  * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #ifndef	_SYS_DMU_H
27 #define	_SYS_DMU_H
28 
29 /*
30  * This file describes the interface that the DMU provides for its
31  * consumers.
32  *
33  * The DMU also interacts with the SPA.  That interface is described in
34  * dmu_spa.h.
35  */
36 
37 #include <sys/inttypes.h>
38 #include <sys/types.h>
39 #include <sys/param.h>
40 #include <sys/cred.h>
41 #include <sys/time.h>
42 
43 #ifdef	__cplusplus
44 extern "C" {
45 #endif
46 
47 struct uio;
48 struct xuio;
49 struct page;
50 struct vnode;
51 struct spa;
52 struct zilog;
53 struct zio;
54 struct blkptr;
55 struct zap_cursor;
56 struct dsl_dataset;
57 struct dsl_pool;
58 struct dnode;
59 struct drr_begin;
60 struct drr_end;
61 struct zbookmark;
62 struct spa;
63 struct nvlist;
64 struct arc_buf;
65 struct zio_prop;
66 
67 typedef struct objset objset_t;
68 typedef struct dmu_tx dmu_tx_t;
69 typedef struct dsl_dir dsl_dir_t;
70 
71 typedef enum dmu_object_type {
72 	DMU_OT_NONE,
73 	/* general: */
74 	DMU_OT_OBJECT_DIRECTORY,	/* ZAP */
75 	DMU_OT_OBJECT_ARRAY,		/* UINT64 */
76 	DMU_OT_PACKED_NVLIST,		/* UINT8 (XDR by nvlist_pack/unpack) */
77 	DMU_OT_PACKED_NVLIST_SIZE,	/* UINT64 */
78 	DMU_OT_BPLIST,			/* UINT64 */
79 	DMU_OT_BPLIST_HDR,		/* UINT64 */
80 	/* spa: */
81 	DMU_OT_SPACE_MAP_HEADER,	/* UINT64 */
82 	DMU_OT_SPACE_MAP,		/* UINT64 */
83 	/* zil: */
84 	DMU_OT_INTENT_LOG,		/* UINT64 */
85 	/* dmu: */
86 	DMU_OT_DNODE,			/* DNODE */
87 	DMU_OT_OBJSET,			/* OBJSET */
88 	/* dsl: */
89 	DMU_OT_DSL_DIR,			/* UINT64 */
90 	DMU_OT_DSL_DIR_CHILD_MAP,	/* ZAP */
91 	DMU_OT_DSL_DS_SNAP_MAP,		/* ZAP */
92 	DMU_OT_DSL_PROPS,		/* ZAP */
93 	DMU_OT_DSL_DATASET,		/* UINT64 */
94 	/* zpl: */
95 	DMU_OT_ZNODE,			/* ZNODE */
96 	DMU_OT_OLDACL,			/* Old ACL */
97 	DMU_OT_PLAIN_FILE_CONTENTS,	/* UINT8 */
98 	DMU_OT_DIRECTORY_CONTENTS,	/* ZAP */
99 	DMU_OT_MASTER_NODE,		/* ZAP */
100 	DMU_OT_UNLINKED_SET,		/* ZAP */
101 	/* zvol: */
102 	DMU_OT_ZVOL,			/* UINT8 */
103 	DMU_OT_ZVOL_PROP,		/* ZAP */
104 	/* other; for testing only! */
105 	DMU_OT_PLAIN_OTHER,		/* UINT8 */
106 	DMU_OT_UINT64_OTHER,		/* UINT64 */
107 	DMU_OT_ZAP_OTHER,		/* ZAP */
108 	/* new object types: */
109 	DMU_OT_ERROR_LOG,		/* ZAP */
110 	DMU_OT_SPA_HISTORY,		/* UINT8 */
111 	DMU_OT_SPA_HISTORY_OFFSETS,	/* spa_his_phys_t */
112 	DMU_OT_POOL_PROPS,		/* ZAP */
113 	DMU_OT_DSL_PERMS,		/* ZAP */
114 	DMU_OT_ACL,			/* ACL */
115 	DMU_OT_SYSACL,			/* SYSACL */
116 	DMU_OT_FUID,			/* FUID table (Packed NVLIST UINT8) */
117 	DMU_OT_FUID_SIZE,		/* FUID table size UINT64 */
118 	DMU_OT_NEXT_CLONES,		/* ZAP */
119 	DMU_OT_SCRUB_QUEUE,		/* ZAP */
120 	DMU_OT_USERGROUP_USED,		/* ZAP */
121 	DMU_OT_USERGROUP_QUOTA,		/* ZAP */
122 	DMU_OT_USERREFS,		/* ZAP */
123 	DMU_OT_DDT_ZAP,			/* ZAP */
124 	DMU_OT_DDT_STATS,		/* ZAP */
125 	DMU_OT_NUMTYPES
126 } dmu_object_type_t;
127 
128 typedef enum dmu_objset_type {
129 	DMU_OST_NONE,
130 	DMU_OST_META,
131 	DMU_OST_ZFS,
132 	DMU_OST_ZVOL,
133 	DMU_OST_OTHER,			/* For testing only! */
134 	DMU_OST_ANY,			/* Be careful! */
135 	DMU_OST_NUMTYPES
136 } dmu_objset_type_t;
137 
138 void byteswap_uint64_array(void *buf, size_t size);
139 void byteswap_uint32_array(void *buf, size_t size);
140 void byteswap_uint16_array(void *buf, size_t size);
141 void byteswap_uint8_array(void *buf, size_t size);
142 void zap_byteswap(void *buf, size_t size);
143 void zfs_oldacl_byteswap(void *buf, size_t size);
144 void zfs_acl_byteswap(void *buf, size_t size);
145 void zfs_znode_byteswap(void *buf, size_t size);
146 
147 #define	DS_FIND_SNAPSHOTS	(1<<0)
148 #define	DS_FIND_CHILDREN	(1<<1)
149 
150 /*
151  * The maximum number of bytes that can be accessed as part of one
152  * operation, including metadata.
153  */
154 #define	DMU_MAX_ACCESS (10<<20) /* 10MB */
155 #define	DMU_MAX_DELETEBLKCNT (20480) /* ~5MB of indirect blocks */
156 
157 #define	DMU_USERUSED_OBJECT	(-1ULL)
158 #define	DMU_GROUPUSED_OBJECT	(-2ULL)
159 #define	DMU_DEADLIST_OBJECT	(-3ULL)
160 
161 /*
162  * Public routines to create, destroy, open, and close objsets.
163  */
164 int dmu_objset_hold(const char *name, void *tag, objset_t **osp);
165 int dmu_objset_own(const char *name, dmu_objset_type_t type,
166     boolean_t readonly, void *tag, objset_t **osp);
167 void dmu_objset_rele(objset_t *os, void *tag);
168 void dmu_objset_disown(objset_t *os, void *tag);
169 int dmu_objset_open_ds(struct dsl_dataset *ds, objset_t **osp);
170 
171 int dmu_objset_evict_dbufs(objset_t *os);
172 int dmu_objset_create(const char *name, dmu_objset_type_t type, uint64_t flags,
173     void (*func)(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx), void *arg);
174 int dmu_objset_clone(const char *name, struct dsl_dataset *clone_origin,
175     uint64_t flags);
176 int dmu_objset_destroy(const char *name, boolean_t defer);
177 int dmu_snapshots_destroy(char *fsname, char *snapname, boolean_t defer);
178 int dmu_objset_snapshot(char *fsname, char *snapname, struct nvlist *props,
179     boolean_t recursive);
180 int dmu_objset_rename(const char *name, const char *newname,
181     boolean_t recursive);
182 int dmu_objset_find(char *name, int func(const char *, void *), void *arg,
183     int flags);
184 void dmu_objset_byteswap(void *buf, size_t size);
185 
186 typedef struct dmu_buf {
187 	uint64_t db_object;		/* object that this buffer is part of */
188 	uint64_t db_offset;		/* byte offset in this object */
189 	uint64_t db_size;		/* size of buffer in bytes */
190 	void *db_data;			/* data in buffer */
191 } dmu_buf_t;
192 
193 typedef void dmu_buf_evict_func_t(struct dmu_buf *db, void *user_ptr);
194 
195 /*
196  * The names of zap entries in the DIRECTORY_OBJECT of the MOS.
197  */
198 #define	DMU_POOL_DIRECTORY_OBJECT	1
199 #define	DMU_POOL_CONFIG			"config"
200 #define	DMU_POOL_ROOT_DATASET		"root_dataset"
201 #define	DMU_POOL_SYNC_BPLIST		"sync_bplist"
202 #define	DMU_POOL_ERRLOG_SCRUB		"errlog_scrub"
203 #define	DMU_POOL_ERRLOG_LAST		"errlog_last"
204 #define	DMU_POOL_SPARES			"spares"
205 #define	DMU_POOL_DEFLATE		"deflate"
206 #define	DMU_POOL_HISTORY		"history"
207 #define	DMU_POOL_PROPS			"pool_props"
208 #define	DMU_POOL_L2CACHE		"l2cache"
209 #define	DMU_POOL_TMP_USERREFS		"tmp_userrefs"
210 #define	DMU_POOL_DDT			"DDT-%s-%s-%s"
211 #define	DMU_POOL_DDT_STATS		"DDT-statistics"
212 
213 /* 4x8 zbookmark_t */
214 #define	DMU_POOL_SCRUB_BOOKMARK		"scrub_bookmark"
215 /* 4x8 ddt_bookmark_t */
216 #define	DMU_POOL_SCRUB_DDT_BOOKMARK	"scrub_ddt_bookmark"
217 /* 1x8 max_class */
218 #define	DMU_POOL_SCRUB_DDT_CLASS_MAX	"scrub_ddt_class_max"
219 /* 1x8 zap obj DMU_OT_SCRUB_QUEUE */
220 #define	DMU_POOL_SCRUB_QUEUE		"scrub_queue"
221 /* 1x8 txg */
222 #define	DMU_POOL_SCRUB_MIN_TXG		"scrub_min_txg"
223 /* 1x8 txg */
224 #define	DMU_POOL_SCRUB_MAX_TXG		"scrub_max_txg"
225 /* 1x4 enum scrub_func */
226 #define	DMU_POOL_SCRUB_FUNC		"scrub_func"
227 /* 1x8 count */
228 #define	DMU_POOL_SCRUB_ERRORS		"scrub_errors"
229 
230 /*
231  * Allocate an object from this objset.  The range of object numbers
232  * available is (0, DN_MAX_OBJECT).  Object 0 is the meta-dnode.
233  *
234  * The transaction must be assigned to a txg.  The newly allocated
235  * object will be "held" in the transaction (ie. you can modify the
236  * newly allocated object in this transaction).
237  *
238  * dmu_object_alloc() chooses an object and returns it in *objectp.
239  *
240  * dmu_object_claim() allocates a specific object number.  If that
241  * number is already allocated, it fails and returns EEXIST.
242  *
243  * Return 0 on success, or ENOSPC or EEXIST as specified above.
244  */
245 uint64_t dmu_object_alloc(objset_t *os, dmu_object_type_t ot,
246     int blocksize, dmu_object_type_t bonus_type, int bonus_len, dmu_tx_t *tx);
247 int dmu_object_claim(objset_t *os, uint64_t object, dmu_object_type_t ot,
248     int blocksize, dmu_object_type_t bonus_type, int bonus_len, dmu_tx_t *tx);
249 int dmu_object_reclaim(objset_t *os, uint64_t object, dmu_object_type_t ot,
250     int blocksize, dmu_object_type_t bonustype, int bonuslen);
251 
252 /*
253  * Free an object from this objset.
254  *
255  * The object's data will be freed as well (ie. you don't need to call
256  * dmu_free(object, 0, -1, tx)).
257  *
258  * The object need not be held in the transaction.
259  *
260  * If there are any holds on this object's buffers (via dmu_buf_hold()),
261  * or tx holds on the object (via dmu_tx_hold_object()), you can not
262  * free it; it fails and returns EBUSY.
263  *
264  * If the object is not allocated, it fails and returns ENOENT.
265  *
266  * Return 0 on success, or EBUSY or ENOENT as specified above.
267  */
268 int dmu_object_free(objset_t *os, uint64_t object, dmu_tx_t *tx);
269 
270 /*
271  * Find the next allocated or free object.
272  *
273  * The objectp parameter is in-out.  It will be updated to be the next
274  * object which is allocated.  Ignore objects which have not been
275  * modified since txg.
276  *
277  * XXX Can only be called on a objset with no dirty data.
278  *
279  * Returns 0 on success, or ENOENT if there are no more objects.
280  */
281 int dmu_object_next(objset_t *os, uint64_t *objectp,
282     boolean_t hole, uint64_t txg);
283 
284 /*
285  * Set the data blocksize for an object.
286  *
287  * The object cannot have any blocks allcated beyond the first.  If
288  * the first block is allocated already, the new size must be greater
289  * than the current block size.  If these conditions are not met,
290  * ENOTSUP will be returned.
291  *
292  * Returns 0 on success, or EBUSY if there are any holds on the object
293  * contents, or ENOTSUP as described above.
294  */
295 int dmu_object_set_blocksize(objset_t *os, uint64_t object, uint64_t size,
296     int ibs, dmu_tx_t *tx);
297 
298 /*
299  * Set the checksum property on a dnode.  The new checksum algorithm will
300  * apply to all newly written blocks; existing blocks will not be affected.
301  */
302 void dmu_object_set_checksum(objset_t *os, uint64_t object, uint8_t checksum,
303     dmu_tx_t *tx);
304 
305 /*
306  * Set the compress property on a dnode.  The new compression algorithm will
307  * apply to all newly written blocks; existing blocks will not be affected.
308  */
309 void dmu_object_set_compress(objset_t *os, uint64_t object, uint8_t compress,
310     dmu_tx_t *tx);
311 
312 /*
313  * Decide how to write a block: checksum, compression, number of copies, etc.
314  */
315 #define	WP_NOFILL	0x1
316 #define	WP_DMU_SYNC	0x2
317 
318 void dmu_write_policy(objset_t *os, struct dnode *dn, int level, int wp,
319     struct zio_prop *zp);
320 /*
321  * The bonus data is accessed more or less like a regular buffer.
322  * You must dmu_bonus_hold() to get the buffer, which will give you a
323  * dmu_buf_t with db_offset==-1ULL, and db_size = the size of the bonus
324  * data.  As with any normal buffer, you must call dmu_buf_read() to
325  * read db_data, dmu_buf_will_dirty() before modifying it, and the
326  * object must be held in an assigned transaction before calling
327  * dmu_buf_will_dirty.  You may use dmu_buf_set_user() on the bonus
328  * buffer as well.  You must release your hold with dmu_buf_rele().
329  */
330 int dmu_bonus_hold(objset_t *os, uint64_t object, void *tag, dmu_buf_t **);
331 int dmu_bonus_max(void);
332 int dmu_set_bonus(dmu_buf_t *, int, dmu_tx_t *);
333 
334 /*
335  * Obtain the DMU buffer from the specified object which contains the
336  * specified offset.  dmu_buf_hold() puts a "hold" on the buffer, so
337  * that it will remain in memory.  You must release the hold with
338  * dmu_buf_rele().  You musn't access the dmu_buf_t after releasing your
339  * hold.  You must have a hold on any dmu_buf_t* you pass to the DMU.
340  *
341  * You must call dmu_buf_read, dmu_buf_will_dirty, or dmu_buf_will_fill
342  * on the returned buffer before reading or writing the buffer's
343  * db_data.  The comments for those routines describe what particular
344  * operations are valid after calling them.
345  *
346  * The object number must be a valid, allocated object number.
347  */
348 int dmu_buf_hold(objset_t *os, uint64_t object, uint64_t offset,
349     void *tag, dmu_buf_t **);
350 void dmu_buf_add_ref(dmu_buf_t *db, void* tag);
351 void dmu_buf_rele(dmu_buf_t *db, void *tag);
352 uint64_t dmu_buf_refcount(dmu_buf_t *db);
353 
354 /*
355  * dmu_buf_hold_array holds the DMU buffers which contain all bytes in a
356  * range of an object.  A pointer to an array of dmu_buf_t*'s is
357  * returned (in *dbpp).
358  *
359  * dmu_buf_rele_array releases the hold on an array of dmu_buf_t*'s, and
360  * frees the array.  The hold on the array of buffers MUST be released
361  * with dmu_buf_rele_array.  You can NOT release the hold on each buffer
362  * individually with dmu_buf_rele.
363  */
364 int dmu_buf_hold_array_by_bonus(dmu_buf_t *db, uint64_t offset,
365     uint64_t length, int read, void *tag, int *numbufsp, dmu_buf_t ***dbpp);
366 void dmu_buf_rele_array(dmu_buf_t **, int numbufs, void *tag);
367 
368 /*
369  * Returns NULL on success, or the existing user ptr if it's already
370  * been set.
371  *
372  * user_ptr is for use by the user and can be obtained via dmu_buf_get_user().
373  *
374  * user_data_ptr_ptr should be NULL, or a pointer to a pointer which
375  * will be set to db->db_data when you are allowed to access it.  Note
376  * that db->db_data (the pointer) can change when you do dmu_buf_read(),
377  * dmu_buf_tryupgrade(), dmu_buf_will_dirty(), or dmu_buf_will_fill().
378  * *user_data_ptr_ptr will be set to the new value when it changes.
379  *
380  * If non-NULL, pageout func will be called when this buffer is being
381  * excised from the cache, so that you can clean up the data structure
382  * pointed to by user_ptr.
383  *
384  * dmu_evict_user() will call the pageout func for all buffers in a
385  * objset with a given pageout func.
386  */
387 void *dmu_buf_set_user(dmu_buf_t *db, void *user_ptr, void *user_data_ptr_ptr,
388     dmu_buf_evict_func_t *pageout_func);
389 /*
390  * set_user_ie is the same as set_user, but request immediate eviction
391  * when hold count goes to zero.
392  */
393 void *dmu_buf_set_user_ie(dmu_buf_t *db, void *user_ptr,
394     void *user_data_ptr_ptr, dmu_buf_evict_func_t *pageout_func);
395 void *dmu_buf_update_user(dmu_buf_t *db_fake, void *old_user_ptr,
396     void *user_ptr, void *user_data_ptr_ptr,
397     dmu_buf_evict_func_t *pageout_func);
398 void dmu_evict_user(objset_t *os, dmu_buf_evict_func_t *func);
399 
400 /*
401  * Returns the user_ptr set with dmu_buf_set_user(), or NULL if not set.
402  */
403 void *dmu_buf_get_user(dmu_buf_t *db);
404 
405 /*
406  * Indicate that you are going to modify the buffer's data (db_data).
407  *
408  * The transaction (tx) must be assigned to a txg (ie. you've called
409  * dmu_tx_assign()).  The buffer's object must be held in the tx
410  * (ie. you've called dmu_tx_hold_object(tx, db->db_object)).
411  */
412 void dmu_buf_will_dirty(dmu_buf_t *db, dmu_tx_t *tx);
413 
414 /*
415  * Tells if the given dbuf is freeable.
416  */
417 boolean_t dmu_buf_freeable(dmu_buf_t *);
418 
419 /*
420  * You must create a transaction, then hold the objects which you will
421  * (or might) modify as part of this transaction.  Then you must assign
422  * the transaction to a transaction group.  Once the transaction has
423  * been assigned, you can modify buffers which belong to held objects as
424  * part of this transaction.  You can't modify buffers before the
425  * transaction has been assigned; you can't modify buffers which don't
426  * belong to objects which this transaction holds; you can't hold
427  * objects once the transaction has been assigned.  You may hold an
428  * object which you are going to free (with dmu_object_free()), but you
429  * don't have to.
430  *
431  * You can abort the transaction before it has been assigned.
432  *
433  * Note that you may hold buffers (with dmu_buf_hold) at any time,
434  * regardless of transaction state.
435  */
436 
437 #define	DMU_NEW_OBJECT	(-1ULL)
438 #define	DMU_OBJECT_END	(-1ULL)
439 
440 dmu_tx_t *dmu_tx_create(objset_t *os);
441 void dmu_tx_hold_write(dmu_tx_t *tx, uint64_t object, uint64_t off, int len);
442 void dmu_tx_hold_free(dmu_tx_t *tx, uint64_t object, uint64_t off,
443     uint64_t len);
444 void dmu_tx_hold_zap(dmu_tx_t *tx, uint64_t object, int add, const char *name);
445 void dmu_tx_hold_bonus(dmu_tx_t *tx, uint64_t object);
446 void dmu_tx_abort(dmu_tx_t *tx);
447 int dmu_tx_assign(dmu_tx_t *tx, uint64_t txg_how);
448 void dmu_tx_wait(dmu_tx_t *tx);
449 void dmu_tx_commit(dmu_tx_t *tx);
450 
451 /*
452  * To register a commit callback, dmu_tx_callback_register() must be called.
453  *
454  * dcb_data is a pointer to caller private data that is passed on as a
455  * callback parameter. The caller is responsible for properly allocating and
456  * freeing it.
457  *
458  * When registering a callback, the transaction must be already created, but
459  * it cannot be committed or aborted. It can be assigned to a txg or not.
460  *
461  * The callback will be called after the transaction has been safely written
462  * to stable storage and will also be called if the dmu_tx is aborted.
463  * If there is any error which prevents the transaction from being committed to
464  * disk, the callback will be called with a value of error != 0.
465  */
466 typedef void dmu_tx_callback_func_t(void *dcb_data, int error);
467 
468 void dmu_tx_callback_register(dmu_tx_t *tx, dmu_tx_callback_func_t *dcb_func,
469     void *dcb_data);
470 
471 /*
472  * Free up the data blocks for a defined range of a file.  If size is
473  * zero, the range from offset to end-of-file is freed.
474  */
475 int dmu_free_range(objset_t *os, uint64_t object, uint64_t offset,
476 	uint64_t size, dmu_tx_t *tx);
477 int dmu_free_long_range(objset_t *os, uint64_t object, uint64_t offset,
478 	uint64_t size);
479 int dmu_free_object(objset_t *os, uint64_t object);
480 
481 /*
482  * Convenience functions.
483  *
484  * Canfail routines will return 0 on success, or an errno if there is a
485  * nonrecoverable I/O error.
486  */
487 #define	DMU_READ_PREFETCH	0 /* prefetch */
488 #define	DMU_READ_NO_PREFETCH	1 /* don't prefetch */
489 int dmu_read(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
490 	void *buf, uint32_t flags);
491 void dmu_write(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
492 	const void *buf, dmu_tx_t *tx);
493 void dmu_prealloc(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
494 	dmu_tx_t *tx);
495 int dmu_read_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size);
496 int dmu_write_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size,
497     dmu_tx_t *tx);
498 int dmu_write_pages(objset_t *os, uint64_t object, uint64_t offset,
499     uint64_t size, struct page *pp, dmu_tx_t *tx);
500 struct arc_buf *dmu_request_arcbuf(dmu_buf_t *handle, int size);
501 void dmu_return_arcbuf(struct arc_buf *buf);
502 void dmu_assign_arcbuf(dmu_buf_t *handle, uint64_t offset, struct arc_buf *buf,
503     dmu_tx_t *tx);
504 int dmu_xuio_init(struct xuio *uio, int niov);
505 void dmu_xuio_fini(struct xuio *uio);
506 int dmu_xuio_add(struct xuio *uio, struct arc_buf *abuf, offset_t off,
507     size_t n);
508 int dmu_xuio_cnt(struct xuio *uio);
509 struct arc_buf *dmu_xuio_arcbuf(struct xuio *uio, int i);
510 void dmu_xuio_clear(struct xuio *uio, int i);
511 void xuio_stat_wbuf_copied();
512 void xuio_stat_wbuf_nocopy();
513 
514 extern int zfs_prefetch_disable;
515 
516 /*
517  * Asynchronously try to read in the data.
518  */
519 void dmu_prefetch(objset_t *os, uint64_t object, uint64_t offset,
520     uint64_t len);
521 
522 typedef struct dmu_object_info {
523 	/* All sizes are in bytes unless otherwise indicated. */
524 	uint32_t doi_data_block_size;
525 	uint32_t doi_metadata_block_size;
526 	dmu_object_type_t doi_type;
527 	dmu_object_type_t doi_bonus_type;
528 	uint64_t doi_bonus_size;
529 	uint8_t doi_indirection;		/* 2 = dnode->indirect->data */
530 	uint8_t doi_checksum;
531 	uint8_t doi_compress;
532 	uint8_t doi_pad[5];
533 	uint64_t doi_physical_blocks_512;	/* data + metadata, 512b blks */
534 	uint64_t doi_max_offset;
535 	uint64_t doi_fill_count;		/* number of non-empty blocks */
536 } dmu_object_info_t;
537 
538 typedef void arc_byteswap_func_t(void *buf, size_t size);
539 
540 typedef struct dmu_object_type_info {
541 	arc_byteswap_func_t	*ot_byteswap;
542 	boolean_t		ot_metadata;
543 	char			*ot_name;
544 } dmu_object_type_info_t;
545 
546 extern const dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES];
547 
548 /*
549  * Get information on a DMU object.
550  *
551  * Return 0 on success or ENOENT if object is not allocated.
552  *
553  * If doi is NULL, just indicates whether the object exists.
554  */
555 int dmu_object_info(objset_t *os, uint64_t object, dmu_object_info_t *doi);
556 void dmu_object_info_from_dnode(struct dnode *dn, dmu_object_info_t *doi);
557 void dmu_object_info_from_db(dmu_buf_t *db, dmu_object_info_t *doi);
558 void dmu_object_size_from_db(dmu_buf_t *db, uint32_t *blksize,
559     u_longlong_t *nblk512);
560 
561 typedef struct dmu_objset_stats {
562 	uint64_t dds_num_clones; /* number of clones of this */
563 	uint64_t dds_creation_txg;
564 	uint64_t dds_guid;
565 	dmu_objset_type_t dds_type;
566 	uint8_t dds_is_snapshot;
567 	uint8_t dds_inconsistent;
568 	char dds_origin[MAXNAMELEN];
569 } dmu_objset_stats_t;
570 
571 /*
572  * Get stats on a dataset.
573  */
574 void dmu_objset_fast_stat(objset_t *os, dmu_objset_stats_t *stat);
575 
576 /*
577  * Add entries to the nvlist for all the objset's properties.  See
578  * zfs_prop_table[] and zfs(1m) for details on the properties.
579  */
580 void dmu_objset_stats(objset_t *os, struct nvlist *nv);
581 
582 /*
583  * Get the space usage statistics for statvfs().
584  *
585  * refdbytes is the amount of space "referenced" by this objset.
586  * availbytes is the amount of space available to this objset, taking
587  * into account quotas & reservations, assuming that no other objsets
588  * use the space first.  These values correspond to the 'referenced' and
589  * 'available' properties, described in the zfs(1m) manpage.
590  *
591  * usedobjs and availobjs are the number of objects currently allocated,
592  * and available.
593  */
594 void dmu_objset_space(objset_t *os, uint64_t *refdbytesp, uint64_t *availbytesp,
595     uint64_t *usedobjsp, uint64_t *availobjsp);
596 
597 /*
598  * The fsid_guid is a 56-bit ID that can change to avoid collisions.
599  * (Contrast with the ds_guid which is a 64-bit ID that will never
600  * change, so there is a small probability that it will collide.)
601  */
602 uint64_t dmu_objset_fsid_guid(objset_t *os);
603 
604 /*
605  * Get the [cm]time for an objset's snapshot dir
606  */
607 timestruc_t dmu_objset_snap_cmtime(objset_t *os);
608 
609 int dmu_objset_is_snapshot(objset_t *os);
610 
611 extern struct spa *dmu_objset_spa(objset_t *os);
612 extern struct zilog *dmu_objset_zil(objset_t *os);
613 extern struct dsl_pool *dmu_objset_pool(objset_t *os);
614 extern struct dsl_dataset *dmu_objset_ds(objset_t *os);
615 extern void dmu_objset_name(objset_t *os, char *buf);
616 extern dmu_objset_type_t dmu_objset_type(objset_t *os);
617 extern uint64_t dmu_objset_id(objset_t *os);
618 extern uint64_t dmu_objset_logbias(objset_t *os);
619 extern int dmu_snapshot_list_next(objset_t *os, int namelen, char *name,
620     uint64_t *id, uint64_t *offp, boolean_t *case_conflict);
621 extern int dmu_snapshot_realname(objset_t *os, char *name, char *real,
622     int maxlen, boolean_t *conflict);
623 extern int dmu_dir_list_next(objset_t *os, int namelen, char *name,
624     uint64_t *idp, uint64_t *offp);
625 
626 typedef int objset_used_cb_t(dmu_object_type_t bonustype,
627     void *bonus, uint64_t *userp, uint64_t *groupp);
628 extern void dmu_objset_register_type(dmu_objset_type_t ost,
629     objset_used_cb_t *cb);
630 extern void dmu_objset_set_user(objset_t *os, void *user_ptr);
631 extern void *dmu_objset_get_user(objset_t *os);
632 
633 /*
634  * Return the txg number for the given assigned transaction.
635  */
636 uint64_t dmu_tx_get_txg(dmu_tx_t *tx);
637 
638 /*
639  * Synchronous write.
640  * If a parent zio is provided this function initiates a write on the
641  * provided buffer as a child of the parent zio.
642  * In the absence of a parent zio, the write is completed synchronously.
643  * At write completion, blk is filled with the bp of the written block.
644  * Note that while the data covered by this function will be on stable
645  * storage when the write completes this new data does not become a
646  * permanent part of the file until the associated transaction commits.
647  */
648 
649 /*
650  * {zfs,zvol,ztest}_get_done() args
651  */
652 typedef struct zgd {
653 	struct zilog	*zgd_zilog;
654 	struct blkptr	*zgd_bp;
655 	dmu_buf_t	*zgd_db;
656 	struct rl	*zgd_rl;
657 	void		*zgd_private;
658 } zgd_t;
659 
660 typedef void dmu_sync_cb_t(zgd_t *arg, int error);
661 int dmu_sync(struct zio *zio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd);
662 
663 /*
664  * Find the next hole or data block in file starting at *off
665  * Return found offset in *off. Return ESRCH for end of file.
666  */
667 int dmu_offset_next(objset_t *os, uint64_t object, boolean_t hole,
668     uint64_t *off);
669 
670 /*
671  * Initial setup and final teardown.
672  */
673 extern void dmu_init(void);
674 extern void dmu_fini(void);
675 
676 typedef void (*dmu_traverse_cb_t)(objset_t *os, void *arg, struct blkptr *bp,
677     uint64_t object, uint64_t offset, int len);
678 void dmu_traverse_objset(objset_t *os, uint64_t txg_start,
679     dmu_traverse_cb_t cb, void *arg);
680 
681 int dmu_sendbackup(objset_t *tosnap, objset_t *fromsnap, boolean_t fromorigin,
682     struct vnode *vp, offset_t *off);
683 
684 typedef struct dmu_recv_cookie {
685 	/*
686 	 * This structure is opaque!
687 	 *
688 	 * If logical and real are different, we are recving the stream
689 	 * into the "real" temporary clone, and then switching it with
690 	 * the "logical" target.
691 	 */
692 	struct dsl_dataset *drc_logical_ds;
693 	struct dsl_dataset *drc_real_ds;
694 	struct drr_begin *drc_drrb;
695 	char *drc_tosnap;
696 	char *drc_top_ds;
697 	boolean_t drc_newfs;
698 	boolean_t drc_force;
699 } dmu_recv_cookie_t;
700 
701 int dmu_recv_begin(char *tofs, char *tosnap, char *topds, struct drr_begin *,
702     boolean_t force, objset_t *origin, dmu_recv_cookie_t *);
703 int dmu_recv_stream(dmu_recv_cookie_t *drc, struct vnode *vp, offset_t *voffp);
704 int dmu_recv_end(dmu_recv_cookie_t *drc);
705 
706 /* CRC64 table */
707 #define	ZFS_CRC64_POLY	0xC96C5795D7870F42ULL	/* ECMA-182, reflected form */
708 extern uint64_t zfs_crc64_table[256];
709 
710 #ifdef	__cplusplus
711 }
712 #endif
713 
714 #endif	/* _SYS_DMU_H */
715