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34dc7c2f BB |
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 | */ | |
9b7b9cd3 | 21 | |
34dc7c2f | 22 | /* |
428870ff | 23 | * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. |
83017311 | 24 | * Copyright (c) 2013 by Delphix. All rights reserved. |
9b7b9cd3 | 25 | * Copyright 2017 Nexenta Systems, Inc. |
34dc7c2f BB |
26 | */ |
27 | ||
28 | #ifndef _SYS_ZAP_H | |
29 | #define _SYS_ZAP_H | |
30 | ||
34dc7c2f BB |
31 | /* |
32 | * ZAP - ZFS Attribute Processor | |
33 | * | |
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). | |
37 | * | |
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. | |
41 | * | |
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. | |
51 | * | |
52 | * The ZAP routines are thread-safe. However, you must observe the | |
53 | * DMU's restriction that a transaction may not be operated on | |
54 | * concurrently. | |
55 | * | |
56 | * Any of the routines that return an int may return an I/O error (EIO | |
57 | * or ECHECKSUM). | |
58 | * | |
59 | * | |
60 | * Implementation / Performance Notes: | |
61 | * | |
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. | |
66 | * | |
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). | |
74 | */ | |
75 | ||
76 | /* | |
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. | |
82 | */ | |
83 | ||
84 | #include <sys/dmu.h> | |
85 | ||
86 | #ifdef __cplusplus | |
87 | extern "C" { | |
88 | #endif | |
89 | ||
34dc7c2f | 90 | /* |
d3cc8b15 | 91 | * Specifies matching criteria for ZAP lookups. |
9b7b9cd3 GM |
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. | |
34dc7c2f | 97 | */ |
9b7b9cd3 GM |
98 | typedef enum matchtype { |
99 | MT_NORMALIZE = 1 << 0, | |
100 | MT_MATCH_CASE = 1 << 1, | |
34dc7c2f BB |
101 | } matchtype_t; |
102 | ||
428870ff BB |
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, | |
108 | /* | |
109 | * First word of key (which must be an array of uint64) is | |
110 | * already randomly distributed. | |
111 | */ | |
112 | ZAP_FLAG_PRE_HASHED_KEY = 1 << 2, | |
113 | } zap_flags_t; | |
114 | ||
34dc7c2f BB |
115 | /* |
116 | * Create a new zapobj with no attributes and return its object number. | |
34dc7c2f BB |
117 | */ |
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); | |
50c957f7 NB |
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); | |
34dc7c2f BB |
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); | |
50c957f7 NB |
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); | |
428870ff BB |
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); | |
50c957f7 NB |
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); | |
6955b401 BB |
134 | uint64_t zap_create_hold(objset_t *os, int normflags, zap_flags_t flags, |
135 | dmu_object_type_t ot, int leaf_blockshift, int indirect_blockshift, | |
136 | dmu_object_type_t bonustype, int bonuslen, int dnodesize, | |
137 | dnode_t **allocated_dnode, void *tag, dmu_tx_t *tx); | |
138 | ||
9ae529ec CS |
139 | uint64_t zap_create_link(objset_t *os, dmu_object_type_t ot, |
140 | uint64_t parent_obj, const char *name, dmu_tx_t *tx); | |
50c957f7 NB |
141 | uint64_t zap_create_link_dnsize(objset_t *os, dmu_object_type_t ot, |
142 | uint64_t parent_obj, const char *name, int dnodesize, dmu_tx_t *tx); | |
34dc7c2f | 143 | |
fa86b5db MA |
144 | /* |
145 | * Initialize an already-allocated object. | |
146 | */ | |
6955b401 BB |
147 | void mzap_create_impl(dnode_t *dn, int normflags, zap_flags_t flags, |
148 | dmu_tx_t *tx); | |
fa86b5db | 149 | |
34dc7c2f BB |
150 | /* |
151 | * Create a new zapobj with no attributes from the given (unallocated) | |
152 | * object number. | |
153 | */ | |
154 | int zap_create_claim(objset_t *ds, uint64_t obj, dmu_object_type_t ot, | |
155 | dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx); | |
50c957f7 NB |
156 | int zap_create_claim_dnsize(objset_t *ds, uint64_t obj, dmu_object_type_t ot, |
157 | dmu_object_type_t bonustype, int bonuslen, int dnodesize, dmu_tx_t *tx); | |
34dc7c2f BB |
158 | int zap_create_claim_norm(objset_t *ds, uint64_t obj, |
159 | int normflags, dmu_object_type_t ot, | |
160 | dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx); | |
50c957f7 NB |
161 | int zap_create_claim_norm_dnsize(objset_t *ds, uint64_t obj, |
162 | int normflags, dmu_object_type_t ot, | |
163 | dmu_object_type_t bonustype, int bonuslen, int dnodesize, dmu_tx_t *tx); | |
34dc7c2f BB |
164 | |
165 | /* | |
166 | * The zapobj passed in must be a valid ZAP object for all of the | |
167 | * following routines. | |
168 | */ | |
169 | ||
170 | /* | |
171 | * Destroy this zapobj and all its attributes. | |
172 | * | |
173 | * Frees the object number using dmu_object_free. | |
174 | */ | |
175 | int zap_destroy(objset_t *ds, uint64_t zapobj, dmu_tx_t *tx); | |
176 | ||
177 | /* | |
178 | * Manipulate attributes. | |
179 | * | |
180 | * 'integer_size' is in bytes, and must be 1, 2, 4, or 8. | |
181 | */ | |
182 | ||
183 | /* | |
184 | * Retrieve the contents of the attribute with the given name. | |
185 | * | |
186 | * If the requested attribute does not exist, the call will fail and | |
187 | * return ENOENT. | |
188 | * | |
189 | * If 'integer_size' is smaller than the attribute's integer size, the | |
190 | * call will fail and return EINVAL. | |
191 | * | |
192 | * If 'integer_size' is equal to or larger than the attribute's integer | |
d3cc8b15 WA |
193 | * size, the call will succeed and return 0. |
194 | * | |
195 | * When converting to a larger integer size, the integers will be treated as | |
196 | * unsigned (ie. no sign-extension will be performed). | |
34dc7c2f BB |
197 | * |
198 | * 'num_integers' is the length (in integers) of 'buf'. | |
199 | * | |
200 | * If the attribute is longer than the buffer, as many integers as will | |
201 | * fit will be transferred to 'buf'. If the entire attribute was not | |
202 | * transferred, the call will return EOVERFLOW. | |
d3cc8b15 WA |
203 | */ |
204 | int zap_lookup(objset_t *ds, uint64_t zapobj, const char *name, | |
205 | uint64_t integer_size, uint64_t num_integers, void *buf); | |
206 | ||
207 | /* | |
34dc7c2f BB |
208 | * If rn_len is nonzero, realname will be set to the name of the found |
209 | * entry (which may be different from the requested name if matchtype is | |
210 | * not MT_EXACT). | |
211 | * | |
212 | * If normalization_conflictp is not NULL, it will be set if there is | |
213 | * another name with the same case/unicode normalized form. | |
214 | */ | |
34dc7c2f BB |
215 | int zap_lookup_norm(objset_t *ds, uint64_t zapobj, const char *name, |
216 | uint64_t integer_size, uint64_t num_integers, void *buf, | |
217 | matchtype_t mt, char *realname, int rn_len, | |
218 | boolean_t *normalization_conflictp); | |
428870ff BB |
219 | int zap_lookup_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key, |
220 | int key_numints, uint64_t integer_size, uint64_t num_integers, void *buf); | |
221 | int zap_contains(objset_t *ds, uint64_t zapobj, const char *name); | |
07248450 | 222 | int zap_prefetch(objset_t *os, uint64_t zapobj, const char *name); |
428870ff BB |
223 | int zap_prefetch_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key, |
224 | int key_numints); | |
34dc7c2f | 225 | |
2bce8049 MA |
226 | int zap_lookup_by_dnode(dnode_t *dn, const char *name, |
227 | uint64_t integer_size, uint64_t num_integers, void *buf); | |
228 | int zap_lookup_norm_by_dnode(dnode_t *dn, const char *name, | |
229 | uint64_t integer_size, uint64_t num_integers, void *buf, | |
230 | matchtype_t mt, char *realname, int rn_len, | |
231 | boolean_t *ncp); | |
232 | ||
233 | int zap_count_write_by_dnode(dnode_t *dn, const char *name, | |
c13060e4 | 234 | int add, zfs_refcount_t *towrite, zfs_refcount_t *tooverwrite); |
9babb374 | 235 | |
34dc7c2f BB |
236 | /* |
237 | * Create an attribute with the given name and value. | |
238 | * | |
239 | * If an attribute with the given name already exists, the call will | |
240 | * fail and return EEXIST. | |
241 | */ | |
428870ff | 242 | int zap_add(objset_t *ds, uint64_t zapobj, const char *key, |
34dc7c2f BB |
243 | int integer_size, uint64_t num_integers, |
244 | const void *val, dmu_tx_t *tx); | |
0eef1bde | 245 | int zap_add_by_dnode(dnode_t *dn, const char *key, |
246 | int integer_size, uint64_t num_integers, | |
247 | const void *val, dmu_tx_t *tx); | |
428870ff BB |
248 | int zap_add_uint64(objset_t *ds, uint64_t zapobj, const uint64_t *key, |
249 | int key_numints, int integer_size, uint64_t num_integers, | |
250 | const void *val, dmu_tx_t *tx); | |
34dc7c2f BB |
251 | |
252 | /* | |
253 | * Set the attribute with the given name to the given value. If an | |
254 | * attribute with the given name does not exist, it will be created. If | |
255 | * an attribute with the given name already exists, the previous value | |
256 | * will be overwritten. The integer_size may be different from the | |
257 | * existing attribute's integer size, in which case the attribute's | |
258 | * integer size will be updated to the new value. | |
259 | */ | |
260 | int zap_update(objset_t *ds, uint64_t zapobj, const char *name, | |
261 | int integer_size, uint64_t num_integers, const void *val, dmu_tx_t *tx); | |
428870ff BB |
262 | int zap_update_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key, |
263 | int key_numints, | |
264 | int integer_size, uint64_t num_integers, const void *val, dmu_tx_t *tx); | |
34dc7c2f BB |
265 | |
266 | /* | |
267 | * Get the length (in integers) and the integer size of the specified | |
268 | * attribute. | |
269 | * | |
270 | * If the requested attribute does not exist, the call will fail and | |
271 | * return ENOENT. | |
272 | */ | |
273 | int zap_length(objset_t *ds, uint64_t zapobj, const char *name, | |
274 | uint64_t *integer_size, uint64_t *num_integers); | |
428870ff BB |
275 | int zap_length_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key, |
276 | int key_numints, uint64_t *integer_size, uint64_t *num_integers); | |
34dc7c2f BB |
277 | |
278 | /* | |
279 | * Remove the specified attribute. | |
280 | * | |
281 | * If the specified attribute does not exist, the call will fail and | |
282 | * return ENOENT. | |
283 | */ | |
284 | int zap_remove(objset_t *ds, uint64_t zapobj, const char *name, dmu_tx_t *tx); | |
285 | int zap_remove_norm(objset_t *ds, uint64_t zapobj, const char *name, | |
286 | matchtype_t mt, dmu_tx_t *tx); | |
0eef1bde | 287 | int zap_remove_by_dnode(dnode_t *dn, const char *name, dmu_tx_t *tx); |
428870ff BB |
288 | int zap_remove_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key, |
289 | int key_numints, dmu_tx_t *tx); | |
34dc7c2f BB |
290 | |
291 | /* | |
292 | * Returns (in *count) the number of attributes in the specified zap | |
293 | * object. | |
294 | */ | |
295 | int zap_count(objset_t *ds, uint64_t zapobj, uint64_t *count); | |
296 | ||
34dc7c2f BB |
297 | /* |
298 | * Returns (in name) the name of the entry whose (value & mask) | |
299 | * (za_first_integer) is value, or ENOENT if not found. The string | |
300 | * pointed to by name must be at least 256 bytes long. If mask==0, the | |
301 | * match must be exact (ie, same as mask=-1ULL). | |
302 | */ | |
303 | int zap_value_search(objset_t *os, uint64_t zapobj, | |
304 | uint64_t value, uint64_t mask, char *name); | |
305 | ||
b128c09f BB |
306 | /* |
307 | * Transfer all the entries from fromobj into intoobj. Only works on | |
308 | * int_size=8 num_integers=1 values. Fails if there are any duplicated | |
309 | * entries. | |
310 | */ | |
311 | int zap_join(objset_t *os, uint64_t fromobj, uint64_t intoobj, dmu_tx_t *tx); | |
312 | ||
428870ff BB |
313 | /* Same as zap_join, but set the values to 'value'. */ |
314 | int zap_join_key(objset_t *os, uint64_t fromobj, uint64_t intoobj, | |
315 | uint64_t value, dmu_tx_t *tx); | |
316 | ||
317 | /* Same as zap_join, but add together any duplicated entries. */ | |
318 | int zap_join_increment(objset_t *os, uint64_t fromobj, uint64_t intoobj, | |
319 | dmu_tx_t *tx); | |
320 | ||
b128c09f BB |
321 | /* |
322 | * Manipulate entries where the name + value are the "same" (the name is | |
323 | * a stringified version of the value). | |
324 | */ | |
325 | int zap_add_int(objset_t *os, uint64_t obj, uint64_t value, dmu_tx_t *tx); | |
326 | int zap_remove_int(objset_t *os, uint64_t obj, uint64_t value, dmu_tx_t *tx); | |
327 | int zap_lookup_int(objset_t *os, uint64_t obj, uint64_t value); | |
428870ff BB |
328 | int zap_increment_int(objset_t *os, uint64_t obj, uint64_t key, int64_t delta, |
329 | dmu_tx_t *tx); | |
330 | ||
331 | /* Here the key is an int and the value is a different int. */ | |
332 | int zap_add_int_key(objset_t *os, uint64_t obj, | |
333 | uint64_t key, uint64_t value, dmu_tx_t *tx); | |
753c3839 MA |
334 | int zap_update_int_key(objset_t *os, uint64_t obj, |
335 | uint64_t key, uint64_t value, dmu_tx_t *tx); | |
428870ff BB |
336 | int zap_lookup_int_key(objset_t *os, uint64_t obj, |
337 | uint64_t key, uint64_t *valuep); | |
338 | ||
428870ff BB |
339 | int zap_increment(objset_t *os, uint64_t obj, const char *name, int64_t delta, |
340 | dmu_tx_t *tx); | |
b128c09f | 341 | |
34dc7c2f BB |
342 | struct zap; |
343 | struct zap_leaf; | |
344 | typedef struct zap_cursor { | |
345 | /* This structure is opaque! */ | |
346 | objset_t *zc_objset; | |
347 | struct zap *zc_zap; | |
348 | struct zap_leaf *zc_leaf; | |
349 | uint64_t zc_zapobj; | |
428870ff | 350 | uint64_t zc_serialized; |
34dc7c2f BB |
351 | uint64_t zc_hash; |
352 | uint32_t zc_cd; | |
353 | } zap_cursor_t; | |
354 | ||
355 | typedef struct { | |
356 | int za_integer_length; | |
357 | /* | |
358 | * za_normalization_conflict will be set if there are additional | |
359 | * entries with this normalized form (eg, "foo" and "Foo"). | |
360 | */ | |
361 | boolean_t za_normalization_conflict; | |
362 | uint64_t za_num_integers; | |
363 | uint64_t za_first_integer; /* no sign extension for <8byte ints */ | |
eca7b760 | 364 | char za_name[ZAP_MAXNAMELEN]; |
34dc7c2f BB |
365 | } zap_attribute_t; |
366 | ||
367 | /* | |
368 | * The interface for listing all the attributes of a zapobj can be | |
369 | * thought of as cursor moving down a list of the attributes one by | |
370 | * one. The cookie returned by the zap_cursor_serialize routine is | |
371 | * persistent across system calls (and across reboot, even). | |
372 | */ | |
373 | ||
374 | /* | |
375 | * Initialize a zap cursor, pointing to the "first" attribute of the | |
376 | * zapobj. You must _fini the cursor when you are done with it. | |
377 | */ | |
378 | void zap_cursor_init(zap_cursor_t *zc, objset_t *ds, uint64_t zapobj); | |
379 | void zap_cursor_fini(zap_cursor_t *zc); | |
380 | ||
381 | /* | |
382 | * Get the attribute currently pointed to by the cursor. Returns | |
383 | * ENOENT if at the end of the attributes. | |
384 | */ | |
385 | int zap_cursor_retrieve(zap_cursor_t *zc, zap_attribute_t *za); | |
386 | ||
387 | /* | |
388 | * Advance the cursor to the next attribute. | |
389 | */ | |
390 | void zap_cursor_advance(zap_cursor_t *zc); | |
391 | ||
392 | /* | |
393 | * Get a persistent cookie pointing to the current position of the zap | |
394 | * cursor. The low 4 bits in the cookie are always zero, and thus can | |
395 | * be used as to differentiate a serialized cookie from a different type | |
396 | * of value. The cookie will be less than 2^32 as long as there are | |
397 | * fewer than 2^22 (4.2 million) entries in the zap object. | |
398 | */ | |
399 | uint64_t zap_cursor_serialize(zap_cursor_t *zc); | |
400 | ||
401 | /* | |
402 | * Initialize a zap cursor pointing to the position recorded by | |
403 | * zap_cursor_serialize (in the "serialized" argument). You can also | |
404 | * use a "serialized" argument of 0 to start at the beginning of the | |
405 | * zapobj (ie. zap_cursor_init_serialized(..., 0) is equivalent to | |
406 | * zap_cursor_init(...).) | |
407 | */ | |
408 | void zap_cursor_init_serialized(zap_cursor_t *zc, objset_t *ds, | |
409 | uint64_t zapobj, uint64_t serialized); | |
410 | ||
411 | ||
412 | #define ZAP_HISTOGRAM_SIZE 10 | |
413 | ||
414 | typedef struct zap_stats { | |
415 | /* | |
416 | * Size of the pointer table (in number of entries). | |
417 | * This is always a power of 2, or zero if it's a microzap. | |
418 | * In general, it should be considerably greater than zs_num_leafs. | |
419 | */ | |
420 | uint64_t zs_ptrtbl_len; | |
421 | ||
422 | uint64_t zs_blocksize; /* size of zap blocks */ | |
423 | ||
424 | /* | |
425 | * The number of blocks used. Note that some blocks may be | |
426 | * wasted because old ptrtbl's and large name/value blocks are | |
427 | * not reused. (Although their space is reclaimed, we don't | |
428 | * reuse those offsets in the object.) | |
429 | */ | |
430 | uint64_t zs_num_blocks; | |
431 | ||
432 | /* | |
433 | * Pointer table values from zap_ptrtbl in the zap_phys_t | |
434 | */ | |
435 | uint64_t zs_ptrtbl_nextblk; /* next (larger) copy start block */ | |
436 | uint64_t zs_ptrtbl_blks_copied; /* number source blocks copied */ | |
437 | uint64_t zs_ptrtbl_zt_blk; /* starting block number */ | |
438 | uint64_t zs_ptrtbl_zt_numblks; /* number of blocks */ | |
439 | uint64_t zs_ptrtbl_zt_shift; /* bits to index it */ | |
440 | ||
441 | /* | |
442 | * Values of the other members of the zap_phys_t | |
443 | */ | |
444 | uint64_t zs_block_type; /* ZBT_HEADER */ | |
445 | uint64_t zs_magic; /* ZAP_MAGIC */ | |
446 | uint64_t zs_num_leafs; /* The number of leaf blocks */ | |
447 | uint64_t zs_num_entries; /* The number of zap entries */ | |
448 | uint64_t zs_salt; /* salt to stir into hash function */ | |
449 | ||
450 | /* | |
451 | * Histograms. For all histograms, the last index | |
452 | * (ZAP_HISTOGRAM_SIZE-1) includes any values which are greater | |
453 | * than what can be represented. For example | |
454 | * zs_leafs_with_n5_entries[ZAP_HISTOGRAM_SIZE-1] is the number | |
455 | * of leafs with more than 45 entries. | |
456 | */ | |
457 | ||
458 | /* | |
459 | * zs_leafs_with_n_pointers[n] is the number of leafs with | |
460 | * 2^n pointers to it. | |
461 | */ | |
462 | uint64_t zs_leafs_with_2n_pointers[ZAP_HISTOGRAM_SIZE]; | |
463 | ||
464 | /* | |
465 | * zs_leafs_with_n_entries[n] is the number of leafs with | |
466 | * [n*5, (n+1)*5) entries. In the current implementation, there | |
467 | * can be at most 55 entries in any block, but there may be | |
468 | * fewer if the name or value is large, or the block is not | |
469 | * completely full. | |
470 | */ | |
471 | uint64_t zs_blocks_with_n5_entries[ZAP_HISTOGRAM_SIZE]; | |
472 | ||
473 | /* | |
474 | * zs_leafs_n_tenths_full[n] is the number of leafs whose | |
475 | * fullness is in the range [n/10, (n+1)/10). | |
476 | */ | |
477 | uint64_t zs_blocks_n_tenths_full[ZAP_HISTOGRAM_SIZE]; | |
478 | ||
479 | /* | |
480 | * zs_entries_using_n_chunks[n] is the number of entries which | |
481 | * consume n 24-byte chunks. (Note, large names/values only use | |
482 | * one chunk, but contribute to zs_num_blocks_large.) | |
483 | */ | |
484 | uint64_t zs_entries_using_n_chunks[ZAP_HISTOGRAM_SIZE]; | |
485 | ||
486 | /* | |
487 | * zs_buckets_with_n_entries[n] is the number of buckets (each | |
488 | * leaf has 64 buckets) with n entries. | |
489 | * zs_buckets_with_n_entries[1] should be very close to | |
490 | * zs_num_entries. | |
491 | */ | |
492 | uint64_t zs_buckets_with_n_entries[ZAP_HISTOGRAM_SIZE]; | |
493 | } zap_stats_t; | |
494 | ||
495 | /* | |
496 | * Get statistics about a ZAP object. Note: you need to be aware of the | |
497 | * internal implementation of the ZAP to correctly interpret some of the | |
498 | * statistics. This interface shouldn't be relied on unless you really | |
499 | * know what you're doing. | |
500 | */ | |
501 | int zap_get_stats(objset_t *ds, uint64_t zapobj, zap_stats_t *zs); | |
502 | ||
503 | #ifdef __cplusplus | |
504 | } | |
505 | #endif | |
506 | ||
507 | #endif /* _SYS_ZAP_H */ |