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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 | /* | |
b128c09f | 22 | * Copyright 2008 Sun Microsystems, Inc. All rights reserved. |
34dc7c2f BB |
23 | * Use is subject to license terms. |
24 | */ | |
25 | ||
26 | #ifndef _SYS_ZAP_H | |
27 | #define _SYS_ZAP_H | |
28 | ||
b128c09f | 29 | #pragma ident "%Z%%M% %I% %E% SMI" |
34dc7c2f BB |
30 | |
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 | ||
90 | #define ZAP_MAXNAMELEN 256 | |
91 | #define ZAP_MAXVALUELEN 1024 | |
92 | ||
93 | /* | |
94 | * The matchtype specifies which entry will be accessed. | |
95 | * MT_EXACT: only find an exact match (non-normalized) | |
96 | * MT_FIRST: find the "first" normalized (case and Unicode | |
97 | * form) match; the designated "first" match will not change as long | |
98 | * as the set of entries with this normalization doesn't change | |
99 | * MT_BEST: if there is an exact match, find that, otherwise find the | |
100 | * first normalized match | |
101 | */ | |
102 | typedef enum matchtype | |
103 | { | |
104 | MT_EXACT, | |
105 | MT_BEST, | |
106 | MT_FIRST | |
107 | } matchtype_t; | |
108 | ||
109 | /* | |
110 | * Create a new zapobj with no attributes and return its object number. | |
111 | * MT_EXACT will cause the zap object to only support MT_EXACT lookups, | |
112 | * otherwise any matchtype can be used for lookups. | |
113 | * | |
114 | * normflags specifies what normalization will be done. values are: | |
115 | * 0: no normalization (legacy on-disk format, supports MT_EXACT matching | |
116 | * only) | |
117 | * U8_TEXTPREP_TOLOWER: case normalization will be performed. | |
118 | * MT_FIRST/MT_BEST matching will find entries that match without | |
119 | * regard to case (eg. looking for "foo" can find an entry "Foo"). | |
120 | * Eventually, other flags will permit unicode normalization as well. | |
121 | */ | |
122 | uint64_t zap_create(objset_t *ds, dmu_object_type_t ot, | |
123 | dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx); | |
124 | uint64_t zap_create_norm(objset_t *ds, int normflags, dmu_object_type_t ot, | |
125 | dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx); | |
126 | ||
127 | /* | |
128 | * Create a new zapobj with no attributes from the given (unallocated) | |
129 | * object number. | |
130 | */ | |
131 | int zap_create_claim(objset_t *ds, uint64_t obj, dmu_object_type_t ot, | |
132 | dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx); | |
133 | int zap_create_claim_norm(objset_t *ds, uint64_t obj, | |
134 | int normflags, dmu_object_type_t ot, | |
135 | dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx); | |
136 | ||
137 | /* | |
138 | * The zapobj passed in must be a valid ZAP object for all of the | |
139 | * following routines. | |
140 | */ | |
141 | ||
142 | /* | |
143 | * Destroy this zapobj and all its attributes. | |
144 | * | |
145 | * Frees the object number using dmu_object_free. | |
146 | */ | |
147 | int zap_destroy(objset_t *ds, uint64_t zapobj, dmu_tx_t *tx); | |
148 | ||
149 | /* | |
150 | * Manipulate attributes. | |
151 | * | |
152 | * 'integer_size' is in bytes, and must be 1, 2, 4, or 8. | |
153 | */ | |
154 | ||
155 | /* | |
156 | * Retrieve the contents of the attribute with the given name. | |
157 | * | |
158 | * If the requested attribute does not exist, the call will fail and | |
159 | * return ENOENT. | |
160 | * | |
161 | * If 'integer_size' is smaller than the attribute's integer size, the | |
162 | * call will fail and return EINVAL. | |
163 | * | |
164 | * If 'integer_size' is equal to or larger than the attribute's integer | |
165 | * size, the call will succeed and return 0. * When converting to a | |
166 | * larger integer size, the integers will be treated as unsigned (ie. no | |
167 | * sign-extension will be performed). | |
168 | * | |
169 | * 'num_integers' is the length (in integers) of 'buf'. | |
170 | * | |
171 | * If the attribute is longer than the buffer, as many integers as will | |
172 | * fit will be transferred to 'buf'. If the entire attribute was not | |
173 | * transferred, the call will return EOVERFLOW. | |
174 | * | |
175 | * If rn_len is nonzero, realname will be set to the name of the found | |
176 | * entry (which may be different from the requested name if matchtype is | |
177 | * not MT_EXACT). | |
178 | * | |
179 | * If normalization_conflictp is not NULL, it will be set if there is | |
180 | * another name with the same case/unicode normalized form. | |
181 | */ | |
182 | int zap_lookup(objset_t *ds, uint64_t zapobj, const char *name, | |
183 | uint64_t integer_size, uint64_t num_integers, void *buf); | |
184 | int zap_lookup_norm(objset_t *ds, uint64_t zapobj, const char *name, | |
185 | uint64_t integer_size, uint64_t num_integers, void *buf, | |
186 | matchtype_t mt, char *realname, int rn_len, | |
187 | boolean_t *normalization_conflictp); | |
188 | ||
189 | /* | |
190 | * Create an attribute with the given name and value. | |
191 | * | |
192 | * If an attribute with the given name already exists, the call will | |
193 | * fail and return EEXIST. | |
194 | */ | |
195 | int zap_add(objset_t *ds, uint64_t zapobj, const char *name, | |
196 | int integer_size, uint64_t num_integers, | |
197 | const void *val, dmu_tx_t *tx); | |
198 | ||
199 | /* | |
200 | * Set the attribute with the given name to the given value. If an | |
201 | * attribute with the given name does not exist, it will be created. If | |
202 | * an attribute with the given name already exists, the previous value | |
203 | * will be overwritten. The integer_size may be different from the | |
204 | * existing attribute's integer size, in which case the attribute's | |
205 | * integer size will be updated to the new value. | |
206 | */ | |
207 | int zap_update(objset_t *ds, uint64_t zapobj, const char *name, | |
208 | int integer_size, uint64_t num_integers, const void *val, dmu_tx_t *tx); | |
209 | ||
210 | /* | |
211 | * Get the length (in integers) and the integer size of the specified | |
212 | * attribute. | |
213 | * | |
214 | * If the requested attribute does not exist, the call will fail and | |
215 | * return ENOENT. | |
216 | */ | |
217 | int zap_length(objset_t *ds, uint64_t zapobj, const char *name, | |
218 | uint64_t *integer_size, uint64_t *num_integers); | |
219 | ||
220 | /* | |
221 | * Remove the specified attribute. | |
222 | * | |
223 | * If the specified attribute does not exist, the call will fail and | |
224 | * return ENOENT. | |
225 | */ | |
226 | int zap_remove(objset_t *ds, uint64_t zapobj, const char *name, dmu_tx_t *tx); | |
227 | int zap_remove_norm(objset_t *ds, uint64_t zapobj, const char *name, | |
228 | matchtype_t mt, dmu_tx_t *tx); | |
229 | ||
230 | /* | |
231 | * Returns (in *count) the number of attributes in the specified zap | |
232 | * object. | |
233 | */ | |
234 | int zap_count(objset_t *ds, uint64_t zapobj, uint64_t *count); | |
235 | ||
236 | ||
237 | /* | |
238 | * Returns (in name) the name of the entry whose (value & mask) | |
239 | * (za_first_integer) is value, or ENOENT if not found. The string | |
240 | * pointed to by name must be at least 256 bytes long. If mask==0, the | |
241 | * match must be exact (ie, same as mask=-1ULL). | |
242 | */ | |
243 | int zap_value_search(objset_t *os, uint64_t zapobj, | |
244 | uint64_t value, uint64_t mask, char *name); | |
245 | ||
b128c09f BB |
246 | /* |
247 | * Transfer all the entries from fromobj into intoobj. Only works on | |
248 | * int_size=8 num_integers=1 values. Fails if there are any duplicated | |
249 | * entries. | |
250 | */ | |
251 | int zap_join(objset_t *os, uint64_t fromobj, uint64_t intoobj, dmu_tx_t *tx); | |
252 | ||
253 | /* | |
254 | * Manipulate entries where the name + value are the "same" (the name is | |
255 | * a stringified version of the value). | |
256 | */ | |
257 | int zap_add_int(objset_t *os, uint64_t obj, uint64_t value, dmu_tx_t *tx); | |
258 | int zap_remove_int(objset_t *os, uint64_t obj, uint64_t value, dmu_tx_t *tx); | |
259 | int zap_lookup_int(objset_t *os, uint64_t obj, uint64_t value); | |
260 | ||
34dc7c2f BB |
261 | struct zap; |
262 | struct zap_leaf; | |
263 | typedef struct zap_cursor { | |
264 | /* This structure is opaque! */ | |
265 | objset_t *zc_objset; | |
266 | struct zap *zc_zap; | |
267 | struct zap_leaf *zc_leaf; | |
268 | uint64_t zc_zapobj; | |
269 | uint64_t zc_hash; | |
270 | uint32_t zc_cd; | |
271 | } zap_cursor_t; | |
272 | ||
273 | typedef struct { | |
274 | int za_integer_length; | |
275 | /* | |
276 | * za_normalization_conflict will be set if there are additional | |
277 | * entries with this normalized form (eg, "foo" and "Foo"). | |
278 | */ | |
279 | boolean_t za_normalization_conflict; | |
280 | uint64_t za_num_integers; | |
281 | uint64_t za_first_integer; /* no sign extension for <8byte ints */ | |
282 | char za_name[MAXNAMELEN]; | |
283 | } zap_attribute_t; | |
284 | ||
285 | /* | |
286 | * The interface for listing all the attributes of a zapobj can be | |
287 | * thought of as cursor moving down a list of the attributes one by | |
288 | * one. The cookie returned by the zap_cursor_serialize routine is | |
289 | * persistent across system calls (and across reboot, even). | |
290 | */ | |
291 | ||
292 | /* | |
293 | * Initialize a zap cursor, pointing to the "first" attribute of the | |
294 | * zapobj. You must _fini the cursor when you are done with it. | |
295 | */ | |
296 | void zap_cursor_init(zap_cursor_t *zc, objset_t *ds, uint64_t zapobj); | |
297 | void zap_cursor_fini(zap_cursor_t *zc); | |
298 | ||
299 | /* | |
300 | * Get the attribute currently pointed to by the cursor. Returns | |
301 | * ENOENT if at the end of the attributes. | |
302 | */ | |
303 | int zap_cursor_retrieve(zap_cursor_t *zc, zap_attribute_t *za); | |
304 | ||
305 | /* | |
306 | * Advance the cursor to the next attribute. | |
307 | */ | |
308 | void zap_cursor_advance(zap_cursor_t *zc); | |
309 | ||
310 | /* | |
311 | * Get a persistent cookie pointing to the current position of the zap | |
312 | * cursor. The low 4 bits in the cookie are always zero, and thus can | |
313 | * be used as to differentiate a serialized cookie from a different type | |
314 | * of value. The cookie will be less than 2^32 as long as there are | |
315 | * fewer than 2^22 (4.2 million) entries in the zap object. | |
316 | */ | |
317 | uint64_t zap_cursor_serialize(zap_cursor_t *zc); | |
318 | ||
319 | /* | |
320 | * Initialize a zap cursor pointing to the position recorded by | |
321 | * zap_cursor_serialize (in the "serialized" argument). You can also | |
322 | * use a "serialized" argument of 0 to start at the beginning of the | |
323 | * zapobj (ie. zap_cursor_init_serialized(..., 0) is equivalent to | |
324 | * zap_cursor_init(...).) | |
325 | */ | |
326 | void zap_cursor_init_serialized(zap_cursor_t *zc, objset_t *ds, | |
327 | uint64_t zapobj, uint64_t serialized); | |
328 | ||
329 | ||
330 | #define ZAP_HISTOGRAM_SIZE 10 | |
331 | ||
332 | typedef struct zap_stats { | |
333 | /* | |
334 | * Size of the pointer table (in number of entries). | |
335 | * This is always a power of 2, or zero if it's a microzap. | |
336 | * In general, it should be considerably greater than zs_num_leafs. | |
337 | */ | |
338 | uint64_t zs_ptrtbl_len; | |
339 | ||
340 | uint64_t zs_blocksize; /* size of zap blocks */ | |
341 | ||
342 | /* | |
343 | * The number of blocks used. Note that some blocks may be | |
344 | * wasted because old ptrtbl's and large name/value blocks are | |
345 | * not reused. (Although their space is reclaimed, we don't | |
346 | * reuse those offsets in the object.) | |
347 | */ | |
348 | uint64_t zs_num_blocks; | |
349 | ||
350 | /* | |
351 | * Pointer table values from zap_ptrtbl in the zap_phys_t | |
352 | */ | |
353 | uint64_t zs_ptrtbl_nextblk; /* next (larger) copy start block */ | |
354 | uint64_t zs_ptrtbl_blks_copied; /* number source blocks copied */ | |
355 | uint64_t zs_ptrtbl_zt_blk; /* starting block number */ | |
356 | uint64_t zs_ptrtbl_zt_numblks; /* number of blocks */ | |
357 | uint64_t zs_ptrtbl_zt_shift; /* bits to index it */ | |
358 | ||
359 | /* | |
360 | * Values of the other members of the zap_phys_t | |
361 | */ | |
362 | uint64_t zs_block_type; /* ZBT_HEADER */ | |
363 | uint64_t zs_magic; /* ZAP_MAGIC */ | |
364 | uint64_t zs_num_leafs; /* The number of leaf blocks */ | |
365 | uint64_t zs_num_entries; /* The number of zap entries */ | |
366 | uint64_t zs_salt; /* salt to stir into hash function */ | |
367 | ||
368 | /* | |
369 | * Histograms. For all histograms, the last index | |
370 | * (ZAP_HISTOGRAM_SIZE-1) includes any values which are greater | |
371 | * than what can be represented. For example | |
372 | * zs_leafs_with_n5_entries[ZAP_HISTOGRAM_SIZE-1] is the number | |
373 | * of leafs with more than 45 entries. | |
374 | */ | |
375 | ||
376 | /* | |
377 | * zs_leafs_with_n_pointers[n] is the number of leafs with | |
378 | * 2^n pointers to it. | |
379 | */ | |
380 | uint64_t zs_leafs_with_2n_pointers[ZAP_HISTOGRAM_SIZE]; | |
381 | ||
382 | /* | |
383 | * zs_leafs_with_n_entries[n] is the number of leafs with | |
384 | * [n*5, (n+1)*5) entries. In the current implementation, there | |
385 | * can be at most 55 entries in any block, but there may be | |
386 | * fewer if the name or value is large, or the block is not | |
387 | * completely full. | |
388 | */ | |
389 | uint64_t zs_blocks_with_n5_entries[ZAP_HISTOGRAM_SIZE]; | |
390 | ||
391 | /* | |
392 | * zs_leafs_n_tenths_full[n] is the number of leafs whose | |
393 | * fullness is in the range [n/10, (n+1)/10). | |
394 | */ | |
395 | uint64_t zs_blocks_n_tenths_full[ZAP_HISTOGRAM_SIZE]; | |
396 | ||
397 | /* | |
398 | * zs_entries_using_n_chunks[n] is the number of entries which | |
399 | * consume n 24-byte chunks. (Note, large names/values only use | |
400 | * one chunk, but contribute to zs_num_blocks_large.) | |
401 | */ | |
402 | uint64_t zs_entries_using_n_chunks[ZAP_HISTOGRAM_SIZE]; | |
403 | ||
404 | /* | |
405 | * zs_buckets_with_n_entries[n] is the number of buckets (each | |
406 | * leaf has 64 buckets) with n entries. | |
407 | * zs_buckets_with_n_entries[1] should be very close to | |
408 | * zs_num_entries. | |
409 | */ | |
410 | uint64_t zs_buckets_with_n_entries[ZAP_HISTOGRAM_SIZE]; | |
411 | } zap_stats_t; | |
412 | ||
413 | /* | |
414 | * Get statistics about a ZAP object. Note: you need to be aware of the | |
415 | * internal implementation of the ZAP to correctly interpret some of the | |
416 | * statistics. This interface shouldn't be relied on unless you really | |
417 | * know what you're doing. | |
418 | */ | |
419 | int zap_get_stats(objset_t *ds, uint64_t zapobj, zap_stats_t *zs); | |
420 | ||
421 | #ifdef __cplusplus | |
422 | } | |
423 | #endif | |
424 | ||
425 | #endif /* _SYS_ZAP_H */ |