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.
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.
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]
23 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
24 * Copyright (c) 2013 by Delphix. All rights reserved.
25 * Copyright 2017 Nexenta Systems, Inc.
32 * ZAP - ZFS Attribute Processor
34 * The ZAP is a module which sits on top of the DMU (Data Management
35 * Unit) and implements a higher-level storage primitive using DMU
36 * objects. Its primary consumer is the ZPL (ZFS Posix Layer).
38 * A "zapobj" is a DMU object which the ZAP uses to stores attributes.
39 * Users should use only zap routines to access a zapobj - they should
40 * not access the DMU object directly using DMU routines.
42 * The attributes stored in a zapobj are name-value pairs. The name is
43 * a zero-terminated string of up to ZAP_MAXNAMELEN bytes (including
44 * terminating NULL). The value is an array of integers, which may be
45 * 1, 2, 4, or 8 bytes long. The total space used by the array (number
46 * of integers * integer length) can be up to ZAP_MAXVALUELEN bytes.
47 * Note that an 8-byte integer value can be used to store the location
48 * (object number) of another dmu object (which may be itself a zapobj).
49 * Note that you can use a zero-length attribute to store a single bit
50 * of information - the attribute is present or not.
52 * The ZAP routines are thread-safe. However, you must observe the
53 * DMU's restriction that a transaction may not be operated on
56 * Any of the routines that return an int may return an I/O error (EIO
60 * Implementation / Performance Notes:
62 * The ZAP is intended to operate most efficiently on attributes with
63 * short (49 bytes or less) names and single 8-byte values, for which
64 * the microzap will be used. The ZAP should be efficient enough so
65 * that the user does not need to cache these attributes.
67 * The ZAP's locking scheme makes its routines thread-safe. Operations
68 * on different zapobjs will be processed concurrently. Operations on
69 * the same zapobj which only read data will be processed concurrently.
70 * Operations on the same zapobj which modify data will be processed
71 * concurrently when there are many attributes in the zapobj (because
72 * the ZAP uses per-block locking - more than 128 * (number of cpus)
73 * small attributes will suffice).
77 * We're using zero-terminated byte strings (ie. ASCII or UTF-8 C
78 * strings) for the names of attributes, rather than a byte string
79 * bounded by an explicit length. If some day we want to support names
80 * in character sets which have embedded zeros (eg. UTF-16, UTF-32),
81 * we'll have to add routines for using length-bounded strings.
91 * Specifies matching criteria for ZAP lookups.
92 * MT_NORMALIZE Use ZAP normalization flags, which can include both
93 * unicode normalization and case-insensitivity.
94 * MT_MATCH_CASE Do case-sensitive lookups even if MT_NORMALIZE is
95 * specified and ZAP normalization flags include
96 * U8_TEXTPREP_TOUPPER.
98 typedef enum matchtype
{
99 MT_NORMALIZE
= 1 << 0,
100 MT_MATCH_CASE
= 1 << 1,
103 typedef enum zap_flags
{
104 /* Use 64-bit hash value (serialized cursors will always use 64-bits) */
105 ZAP_FLAG_HASH64
= 1 << 0,
106 /* Key is binary, not string (zap_add_uint64() can be used) */
107 ZAP_FLAG_UINT64_KEY
= 1 << 1,
109 * First word of key (which must be an array of uint64) is
110 * already randomly distributed.
112 ZAP_FLAG_PRE_HASHED_KEY
= 1 << 2,
116 * Create a new zapobj with no attributes and return its object number.
118 uint64_t zap_create(objset_t
*ds
, dmu_object_type_t ot
,
119 dmu_object_type_t bonustype
, int bonuslen
, dmu_tx_t
*tx
);
120 uint64_t zap_create_dnsize(objset_t
*ds
, dmu_object_type_t ot
,
121 dmu_object_type_t bonustype
, int bonuslen
, int dnodesize
, dmu_tx_t
*tx
);
122 uint64_t zap_create_norm(objset_t
*ds
, int normflags
, dmu_object_type_t ot
,
123 dmu_object_type_t bonustype
, int bonuslen
, dmu_tx_t
*tx
);
124 uint64_t zap_create_norm_dnsize(objset_t
*ds
, int normflags
,
125 dmu_object_type_t ot
, dmu_object_type_t bonustype
, int bonuslen
,
126 int dnodesize
, dmu_tx_t
*tx
);
127 uint64_t zap_create_flags(objset_t
*os
, int normflags
, zap_flags_t flags
,
128 dmu_object_type_t ot
, int leaf_blockshift
, int indirect_blockshift
,
129 dmu_object_type_t bonustype
, int bonuslen
, dmu_tx_t
*tx
);
130 uint64_t zap_create_flags_dnsize(objset_t
*os
, int normflags
,
131 zap_flags_t flags
, dmu_object_type_t ot
, int leaf_blockshift
,
132 int indirect_blockshift
, dmu_object_type_t bonustype
, int bonuslen
,
133 int dnodesize
, dmu_tx_t
*tx
);
134 uint64_t zap_create_link(objset_t
*os
, dmu_object_type_t ot
,
135 uint64_t parent_obj
, const char *name
, dmu_tx_t
*tx
);
136 uint64_t zap_create_link_dnsize(objset_t
*os
, dmu_object_type_t ot
,
137 uint64_t parent_obj
, const char *name
, int dnodesize
, dmu_tx_t
*tx
);
140 * Initialize an already-allocated object.
142 void mzap_create_impl(objset_t
*os
, uint64_t obj
, int normflags
,
143 zap_flags_t flags
, dmu_tx_t
*tx
);
146 * Create a new zapobj with no attributes from the given (unallocated)
149 int zap_create_claim(objset_t
*ds
, uint64_t obj
, dmu_object_type_t ot
,
150 dmu_object_type_t bonustype
, int bonuslen
, dmu_tx_t
*tx
);
151 int zap_create_claim_dnsize(objset_t
*ds
, uint64_t obj
, dmu_object_type_t ot
,
152 dmu_object_type_t bonustype
, int bonuslen
, int dnodesize
, dmu_tx_t
*tx
);
153 int zap_create_claim_norm(objset_t
*ds
, uint64_t obj
,
154 int normflags
, dmu_object_type_t ot
,
155 dmu_object_type_t bonustype
, int bonuslen
, dmu_tx_t
*tx
);
156 int zap_create_claim_norm_dnsize(objset_t
*ds
, uint64_t obj
,
157 int normflags
, dmu_object_type_t ot
,
158 dmu_object_type_t bonustype
, int bonuslen
, int dnodesize
, dmu_tx_t
*tx
);
161 * The zapobj passed in must be a valid ZAP object for all of the
162 * following routines.
166 * Destroy this zapobj and all its attributes.
168 * Frees the object number using dmu_object_free.
170 int zap_destroy(objset_t
*ds
, uint64_t zapobj
, dmu_tx_t
*tx
);
173 * Manipulate attributes.
175 * 'integer_size' is in bytes, and must be 1, 2, 4, or 8.
179 * Retrieve the contents of the attribute with the given name.
181 * If the requested attribute does not exist, the call will fail and
184 * If 'integer_size' is smaller than the attribute's integer size, the
185 * call will fail and return EINVAL.
187 * If 'integer_size' is equal to or larger than the attribute's integer
188 * size, the call will succeed and return 0.
190 * When converting to a larger integer size, the integers will be treated as
191 * unsigned (ie. no sign-extension will be performed).
193 * 'num_integers' is the length (in integers) of 'buf'.
195 * If the attribute is longer than the buffer, as many integers as will
196 * fit will be transferred to 'buf'. If the entire attribute was not
197 * transferred, the call will return EOVERFLOW.
199 int zap_lookup(objset_t
*ds
, uint64_t zapobj
, const char *name
,
200 uint64_t integer_size
, uint64_t num_integers
, void *buf
);
203 * If rn_len is nonzero, realname will be set to the name of the found
204 * entry (which may be different from the requested name if matchtype is
207 * If normalization_conflictp is not NULL, it will be set if there is
208 * another name with the same case/unicode normalized form.
210 int zap_lookup_norm(objset_t
*ds
, uint64_t zapobj
, const char *name
,
211 uint64_t integer_size
, uint64_t num_integers
, void *buf
,
212 matchtype_t mt
, char *realname
, int rn_len
,
213 boolean_t
*normalization_conflictp
);
214 int zap_lookup_uint64(objset_t
*os
, uint64_t zapobj
, const uint64_t *key
,
215 int key_numints
, uint64_t integer_size
, uint64_t num_integers
, void *buf
);
216 int zap_contains(objset_t
*ds
, uint64_t zapobj
, const char *name
);
217 int zap_prefetch(objset_t
*os
, uint64_t zapobj
, const char *name
);
218 int zap_prefetch_uint64(objset_t
*os
, uint64_t zapobj
, const uint64_t *key
,
221 int zap_lookup_by_dnode(dnode_t
*dn
, const char *name
,
222 uint64_t integer_size
, uint64_t num_integers
, void *buf
);
223 int zap_lookup_norm_by_dnode(dnode_t
*dn
, const char *name
,
224 uint64_t integer_size
, uint64_t num_integers
, void *buf
,
225 matchtype_t mt
, char *realname
, int rn_len
,
228 int zap_count_write_by_dnode(dnode_t
*dn
, const char *name
,
229 int add
, refcount_t
*towrite
, refcount_t
*tooverwrite
);
232 * Create an attribute with the given name and value.
234 * If an attribute with the given name already exists, the call will
235 * fail and return EEXIST.
237 int zap_add(objset_t
*ds
, uint64_t zapobj
, const char *key
,
238 int integer_size
, uint64_t num_integers
,
239 const void *val
, dmu_tx_t
*tx
);
240 int zap_add_by_dnode(dnode_t
*dn
, const char *key
,
241 int integer_size
, uint64_t num_integers
,
242 const void *val
, dmu_tx_t
*tx
);
243 int zap_add_uint64(objset_t
*ds
, uint64_t zapobj
, const uint64_t *key
,
244 int key_numints
, int integer_size
, uint64_t num_integers
,
245 const void *val
, dmu_tx_t
*tx
);
248 * Set the attribute with the given name to the given value. If an
249 * attribute with the given name does not exist, it will be created. If
250 * an attribute with the given name already exists, the previous value
251 * will be overwritten. The integer_size may be different from the
252 * existing attribute's integer size, in which case the attribute's
253 * integer size will be updated to the new value.
255 int zap_update(objset_t
*ds
, uint64_t zapobj
, const char *name
,
256 int integer_size
, uint64_t num_integers
, const void *val
, dmu_tx_t
*tx
);
257 int zap_update_uint64(objset_t
*os
, uint64_t zapobj
, const uint64_t *key
,
259 int integer_size
, uint64_t num_integers
, const void *val
, dmu_tx_t
*tx
);
262 * Get the length (in integers) and the integer size of the specified
265 * If the requested attribute does not exist, the call will fail and
268 int zap_length(objset_t
*ds
, uint64_t zapobj
, const char *name
,
269 uint64_t *integer_size
, uint64_t *num_integers
);
270 int zap_length_uint64(objset_t
*os
, uint64_t zapobj
, const uint64_t *key
,
271 int key_numints
, uint64_t *integer_size
, uint64_t *num_integers
);
274 * Remove the specified attribute.
276 * If the specified attribute does not exist, the call will fail and
279 int zap_remove(objset_t
*ds
, uint64_t zapobj
, const char *name
, dmu_tx_t
*tx
);
280 int zap_remove_norm(objset_t
*ds
, uint64_t zapobj
, const char *name
,
281 matchtype_t mt
, dmu_tx_t
*tx
);
282 int zap_remove_by_dnode(dnode_t
*dn
, const char *name
, dmu_tx_t
*tx
);
283 int zap_remove_uint64(objset_t
*os
, uint64_t zapobj
, const uint64_t *key
,
284 int key_numints
, dmu_tx_t
*tx
);
287 * Returns (in *count) the number of attributes in the specified zap
290 int zap_count(objset_t
*ds
, uint64_t zapobj
, uint64_t *count
);
293 * Returns (in name) the name of the entry whose (value & mask)
294 * (za_first_integer) is value, or ENOENT if not found. The string
295 * pointed to by name must be at least 256 bytes long. If mask==0, the
296 * match must be exact (ie, same as mask=-1ULL).
298 int zap_value_search(objset_t
*os
, uint64_t zapobj
,
299 uint64_t value
, uint64_t mask
, char *name
);
302 * Transfer all the entries from fromobj into intoobj. Only works on
303 * int_size=8 num_integers=1 values. Fails if there are any duplicated
306 int zap_join(objset_t
*os
, uint64_t fromobj
, uint64_t intoobj
, dmu_tx_t
*tx
);
308 /* Same as zap_join, but set the values to 'value'. */
309 int zap_join_key(objset_t
*os
, uint64_t fromobj
, uint64_t intoobj
,
310 uint64_t value
, dmu_tx_t
*tx
);
312 /* Same as zap_join, but add together any duplicated entries. */
313 int zap_join_increment(objset_t
*os
, uint64_t fromobj
, uint64_t intoobj
,
317 * Manipulate entries where the name + value are the "same" (the name is
318 * a stringified version of the value).
320 int zap_add_int(objset_t
*os
, uint64_t obj
, uint64_t value
, dmu_tx_t
*tx
);
321 int zap_remove_int(objset_t
*os
, uint64_t obj
, uint64_t value
, dmu_tx_t
*tx
);
322 int zap_lookup_int(objset_t
*os
, uint64_t obj
, uint64_t value
);
323 int zap_increment_int(objset_t
*os
, uint64_t obj
, uint64_t key
, int64_t delta
,
326 /* Here the key is an int and the value is a different int. */
327 int zap_add_int_key(objset_t
*os
, uint64_t obj
,
328 uint64_t key
, uint64_t value
, dmu_tx_t
*tx
);
329 int zap_update_int_key(objset_t
*os
, uint64_t obj
,
330 uint64_t key
, uint64_t value
, dmu_tx_t
*tx
);
331 int zap_lookup_int_key(objset_t
*os
, uint64_t obj
,
332 uint64_t key
, uint64_t *valuep
);
334 int zap_increment(objset_t
*os
, uint64_t obj
, const char *name
, int64_t delta
,
339 typedef struct zap_cursor
{
340 /* This structure is opaque! */
343 struct zap_leaf
*zc_leaf
;
345 uint64_t zc_serialized
;
351 int za_integer_length
;
353 * za_normalization_conflict will be set if there are additional
354 * entries with this normalized form (eg, "foo" and "Foo").
356 boolean_t za_normalization_conflict
;
357 uint64_t za_num_integers
;
358 uint64_t za_first_integer
; /* no sign extension for <8byte ints */
359 char za_name
[ZAP_MAXNAMELEN
];
363 * The interface for listing all the attributes of a zapobj can be
364 * thought of as cursor moving down a list of the attributes one by
365 * one. The cookie returned by the zap_cursor_serialize routine is
366 * persistent across system calls (and across reboot, even).
370 * Initialize a zap cursor, pointing to the "first" attribute of the
371 * zapobj. You must _fini the cursor when you are done with it.
373 void zap_cursor_init(zap_cursor_t
*zc
, objset_t
*ds
, uint64_t zapobj
);
374 void zap_cursor_fini(zap_cursor_t
*zc
);
377 * Get the attribute currently pointed to by the cursor. Returns
378 * ENOENT if at the end of the attributes.
380 int zap_cursor_retrieve(zap_cursor_t
*zc
, zap_attribute_t
*za
);
383 * Advance the cursor to the next attribute.
385 void zap_cursor_advance(zap_cursor_t
*zc
);
388 * Get a persistent cookie pointing to the current position of the zap
389 * cursor. The low 4 bits in the cookie are always zero, and thus can
390 * be used as to differentiate a serialized cookie from a different type
391 * of value. The cookie will be less than 2^32 as long as there are
392 * fewer than 2^22 (4.2 million) entries in the zap object.
394 uint64_t zap_cursor_serialize(zap_cursor_t
*zc
);
397 * Initialize a zap cursor pointing to the position recorded by
398 * zap_cursor_serialize (in the "serialized" argument). You can also
399 * use a "serialized" argument of 0 to start at the beginning of the
400 * zapobj (ie. zap_cursor_init_serialized(..., 0) is equivalent to
401 * zap_cursor_init(...).)
403 void zap_cursor_init_serialized(zap_cursor_t
*zc
, objset_t
*ds
,
404 uint64_t zapobj
, uint64_t serialized
);
407 #define ZAP_HISTOGRAM_SIZE 10
409 typedef struct zap_stats
{
411 * Size of the pointer table (in number of entries).
412 * This is always a power of 2, or zero if it's a microzap.
413 * In general, it should be considerably greater than zs_num_leafs.
415 uint64_t zs_ptrtbl_len
;
417 uint64_t zs_blocksize
; /* size of zap blocks */
420 * The number of blocks used. Note that some blocks may be
421 * wasted because old ptrtbl's and large name/value blocks are
422 * not reused. (Although their space is reclaimed, we don't
423 * reuse those offsets in the object.)
425 uint64_t zs_num_blocks
;
428 * Pointer table values from zap_ptrtbl in the zap_phys_t
430 uint64_t zs_ptrtbl_nextblk
; /* next (larger) copy start block */
431 uint64_t zs_ptrtbl_blks_copied
; /* number source blocks copied */
432 uint64_t zs_ptrtbl_zt_blk
; /* starting block number */
433 uint64_t zs_ptrtbl_zt_numblks
; /* number of blocks */
434 uint64_t zs_ptrtbl_zt_shift
; /* bits to index it */
437 * Values of the other members of the zap_phys_t
439 uint64_t zs_block_type
; /* ZBT_HEADER */
440 uint64_t zs_magic
; /* ZAP_MAGIC */
441 uint64_t zs_num_leafs
; /* The number of leaf blocks */
442 uint64_t zs_num_entries
; /* The number of zap entries */
443 uint64_t zs_salt
; /* salt to stir into hash function */
446 * Histograms. For all histograms, the last index
447 * (ZAP_HISTOGRAM_SIZE-1) includes any values which are greater
448 * than what can be represented. For example
449 * zs_leafs_with_n5_entries[ZAP_HISTOGRAM_SIZE-1] is the number
450 * of leafs with more than 45 entries.
454 * zs_leafs_with_n_pointers[n] is the number of leafs with
455 * 2^n pointers to it.
457 uint64_t zs_leafs_with_2n_pointers
[ZAP_HISTOGRAM_SIZE
];
460 * zs_leafs_with_n_entries[n] is the number of leafs with
461 * [n*5, (n+1)*5) entries. In the current implementation, there
462 * can be at most 55 entries in any block, but there may be
463 * fewer if the name or value is large, or the block is not
466 uint64_t zs_blocks_with_n5_entries
[ZAP_HISTOGRAM_SIZE
];
469 * zs_leafs_n_tenths_full[n] is the number of leafs whose
470 * fullness is in the range [n/10, (n+1)/10).
472 uint64_t zs_blocks_n_tenths_full
[ZAP_HISTOGRAM_SIZE
];
475 * zs_entries_using_n_chunks[n] is the number of entries which
476 * consume n 24-byte chunks. (Note, large names/values only use
477 * one chunk, but contribute to zs_num_blocks_large.)
479 uint64_t zs_entries_using_n_chunks
[ZAP_HISTOGRAM_SIZE
];
482 * zs_buckets_with_n_entries[n] is the number of buckets (each
483 * leaf has 64 buckets) with n entries.
484 * zs_buckets_with_n_entries[1] should be very close to
487 uint64_t zs_buckets_with_n_entries
[ZAP_HISTOGRAM_SIZE
];
491 * Get statistics about a ZAP object. Note: you need to be aware of the
492 * internal implementation of the ZAP to correctly interpret some of the
493 * statistics. This interface shouldn't be relied on unless you really
494 * know what you're doing.
496 int zap_get_stats(objset_t
*ds
, uint64_t zapobj
, zap_stats_t
*zs
);
502 #endif /* _SYS_ZAP_H */