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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 23 * Copyright (c) 2013 by Delphix. All rights reserved. 24 */ 25 26 #ifndef _SYS_ZAP_H 27 #define _SYS_ZAP_H 28 29 /* 30 * ZAP - ZFS Attribute Processor 31 * 32 * The ZAP is a module which sits on top of the DMU (Data Management 33 * Unit) and implements a higher-level storage primitive using DMU 34 * objects. Its primary consumer is the ZPL (ZFS Posix Layer). 35 * 36 * A "zapobj" is a DMU object which the ZAP uses to stores attributes. 37 * Users should use only zap routines to access a zapobj - they should 38 * not access the DMU object directly using DMU routines. 39 * 40 * The attributes stored in a zapobj are name-value pairs. The name is 41 * a zero-terminated string of up to ZAP_MAXNAMELEN bytes (including 42 * terminating NULL). The value is an array of integers, which may be 43 * 1, 2, 4, or 8 bytes long. The total space used by the array (number 44 * of integers * integer length) can be up to ZAP_MAXVALUELEN bytes. 45 * Note that an 8-byte integer value can be used to store the location 46 * (object number) of another dmu object (which may be itself a zapobj). 47 * Note that you can use a zero-length attribute to store a single bit 48 * of information - the attribute is present or not. 49 * 50 * The ZAP routines are thread-safe. However, you must observe the 51 * DMU's restriction that a transaction may not be operated on 52 * concurrently. 53 * 54 * Any of the routines that return an int may return an I/O error (EIO 55 * or ECHECKSUM). 56 * 57 * 58 * Implementation / Performance Notes: 59 * 60 * The ZAP is intended to operate most efficiently on attributes with 61 * short (49 bytes or less) names and single 8-byte values, for which 62 * the microzap will be used. The ZAP should be efficient enough so 63 * that the user does not need to cache these attributes. 64 * 65 * The ZAP's locking scheme makes its routines thread-safe. Operations 66 * on different zapobjs will be processed concurrently. Operations on 67 * the same zapobj which only read data will be processed concurrently. 68 * Operations on the same zapobj which modify data will be processed 69 * concurrently when there are many attributes in the zapobj (because 70 * the ZAP uses per-block locking - more than 128 * (number of cpus) 71 * small attributes will suffice). 72 */ 73 74 /* 75 * We're using zero-terminated byte strings (ie. ASCII or UTF-8 C 76 * strings) for the names of attributes, rather than a byte string 77 * bounded by an explicit length. If some day we want to support names 78 * in character sets which have embedded zeros (eg. UTF-16, UTF-32), 79 * we'll have to add routines for using length-bounded strings. 80 */ 81 82 #include <sys/dmu.h> 83 84 #ifdef __cplusplus 85 extern "C" { 86 #endif 87 88 /* 89 * Specifies matching criteria for ZAP lookups. 90 */ 91 typedef enum matchtype 92 { 93 /* Only find an exact match (non-normalized) */ 94 MT_EXACT, 95 /* 96 * If there is an exact match, find that, otherwise find the 97 * first normalized match. 98 */ 99 MT_BEST, 100 /* 101 * Find the "first" normalized (case and Unicode form) match; 102 * the designated "first" match will not change as long as the 103 * set of entries with this normalization doesn't change. 104 */ 105 MT_FIRST 106 } matchtype_t; 107 108 typedef enum zap_flags { 109 /* Use 64-bit hash value (serialized cursors will always use 64-bits) */ 110 ZAP_FLAG_HASH64 = 1 << 0, 111 /* Key is binary, not string (zap_add_uint64() can be used) */ 112 ZAP_FLAG_UINT64_KEY = 1 << 1, 113 /* 114 * First word of key (which must be an array of uint64) is 115 * already randomly distributed. 116 */ 117 ZAP_FLAG_PRE_HASHED_KEY = 1 << 2, 118 } zap_flags_t; 119 120 /* 121 * Create a new zapobj with no attributes and return its object number. 122 * MT_EXACT will cause the zap object to only support MT_EXACT lookups, 123 * otherwise any matchtype can be used for lookups. 124 * 125 * normflags specifies what normalization will be done. values are: 126 * 0: no normalization (legacy on-disk format, supports MT_EXACT matching 127 * only) 128 * U8_TEXTPREP_TOLOWER: case normalization will be performed. 129 * MT_FIRST/MT_BEST matching will find entries that match without 130 * regard to case (eg. looking for "foo" can find an entry "Foo"). 131 * Eventually, other flags will permit unicode normalization as well. 132 */ 133 uint64_t zap_create(objset_t *ds, dmu_object_type_t ot, 134 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx); 135 uint64_t zap_create_norm(objset_t *ds, int normflags, dmu_object_type_t ot, 136 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx); 137 uint64_t zap_create_flags(objset_t *os, int normflags, zap_flags_t flags, 138 dmu_object_type_t ot, int leaf_blockshift, int indirect_blockshift, 139 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx); 140 uint64_t zap_create_link(objset_t *os, dmu_object_type_t ot, 141 uint64_t parent_obj, const char *name, dmu_tx_t *tx); 142 143 /* 144 * Create a new zapobj with no attributes from the given (unallocated) 145 * object number. 146 */ 147 int zap_create_claim(objset_t *ds, uint64_t obj, dmu_object_type_t ot, 148 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx); 149 int zap_create_claim_norm(objset_t *ds, uint64_t obj, 150 int normflags, dmu_object_type_t ot, 151 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx); 152 153 /* 154 * The zapobj passed in must be a valid ZAP object for all of the 155 * following routines. 156 */ 157 158 /* 159 * Destroy this zapobj and all its attributes. 160 * 161 * Frees the object number using dmu_object_free. 162 */ 163 int zap_destroy(objset_t *ds, uint64_t zapobj, dmu_tx_t *tx); 164 165 /* 166 * Manipulate attributes. 167 * 168 * 'integer_size' is in bytes, and must be 1, 2, 4, or 8. 169 */ 170 171 /* 172 * Retrieve the contents of the attribute with the given name. 173 * 174 * If the requested attribute does not exist, the call will fail and 175 * return ENOENT. 176 * 177 * If 'integer_size' is smaller than the attribute's integer size, the 178 * call will fail and return EINVAL. 179 * 180 * If 'integer_size' is equal to or larger than the attribute's integer 181 * size, the call will succeed and return 0. 182 * 183 * When converting to a larger integer size, the integers will be treated as 184 * unsigned (ie. no sign-extension will be performed). 185 * 186 * 'num_integers' is the length (in integers) of 'buf'. 187 * 188 * If the attribute is longer than the buffer, as many integers as will 189 * fit will be transferred to 'buf'. If the entire attribute was not 190 * transferred, the call will return EOVERFLOW. 191 */ 192 int zap_lookup(objset_t *ds, uint64_t zapobj, const char *name, 193 uint64_t integer_size, uint64_t num_integers, void *buf); 194 195 /* 196 * If rn_len is nonzero, realname will be set to the name of the found 197 * entry (which may be different from the requested name if matchtype is 198 * not MT_EXACT). 199 * 200 * If normalization_conflictp is not NULL, it will be set if there is 201 * another name with the same case/unicode normalized form. 202 */ 203 int zap_lookup_norm(objset_t *ds, uint64_t zapobj, const char *name, 204 uint64_t integer_size, uint64_t num_integers, void *buf, 205 matchtype_t mt, char *realname, int rn_len, 206 boolean_t *normalization_conflictp); 207 int zap_lookup_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key, 208 int key_numints, uint64_t integer_size, uint64_t num_integers, void *buf); 209 int zap_contains(objset_t *ds, uint64_t zapobj, const char *name); 210 int zap_prefetch_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key, 211 int key_numints); 212 213 int zap_count_write(objset_t *os, uint64_t zapobj, const char *name, 214 int add, uint64_t *towrite, uint64_t *tooverwrite); 215 216 /* 217 * Create an attribute with the given name and value. 218 * 219 * If an attribute with the given name already exists, the call will 220 * fail and return EEXIST. 221 */ 222 int zap_add(objset_t *ds, uint64_t zapobj, const char *key, 223 int integer_size, uint64_t num_integers, 224 const void *val, dmu_tx_t *tx); 225 int zap_add_uint64(objset_t *ds, uint64_t zapobj, const uint64_t *key, 226 int key_numints, int integer_size, uint64_t num_integers, 227 const void *val, dmu_tx_t *tx); 228 229 /* 230 * Set the attribute with the given name to the given value. If an 231 * attribute with the given name does not exist, it will be created. If 232 * an attribute with the given name already exists, the previous value 233 * will be overwritten. The integer_size may be different from the 234 * existing attribute's integer size, in which case the attribute's 235 * integer size will be updated to the new value. 236 */ 237 int zap_update(objset_t *ds, uint64_t zapobj, const char *name, 238 int integer_size, uint64_t num_integers, const void *val, dmu_tx_t *tx); 239 int zap_update_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key, 240 int key_numints, 241 int integer_size, uint64_t num_integers, const void *val, dmu_tx_t *tx); 242 243 /* 244 * Get the length (in integers) and the integer size of the specified 245 * attribute. 246 * 247 * If the requested attribute does not exist, the call will fail and 248 * return ENOENT. 249 */ 250 int zap_length(objset_t *ds, uint64_t zapobj, const char *name, 251 uint64_t *integer_size, uint64_t *num_integers); 252 int zap_length_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key, 253 int key_numints, uint64_t *integer_size, uint64_t *num_integers); 254 255 /* 256 * Remove the specified attribute. 257 * 258 * If the specified attribute does not exist, the call will fail and 259 * return ENOENT. 260 */ 261 int zap_remove(objset_t *ds, uint64_t zapobj, const char *name, dmu_tx_t *tx); 262 int zap_remove_norm(objset_t *ds, uint64_t zapobj, const char *name, 263 matchtype_t mt, dmu_tx_t *tx); 264 int zap_remove_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key, 265 int key_numints, dmu_tx_t *tx); 266 267 /* 268 * Returns (in *count) the number of attributes in the specified zap 269 * object. 270 */ 271 int zap_count(objset_t *ds, uint64_t zapobj, uint64_t *count); 272 273 /* 274 * Returns (in name) the name of the entry whose (value & mask) 275 * (za_first_integer) is value, or ENOENT if not found. The string 276 * pointed to by name must be at least 256 bytes long. If mask==0, the 277 * match must be exact (ie, same as mask=-1ULL). 278 */ 279 int zap_value_search(objset_t *os, uint64_t zapobj, 280 uint64_t value, uint64_t mask, char *name); 281 282 /* 283 * Transfer all the entries from fromobj into intoobj. Only works on 284 * int_size=8 num_integers=1 values. Fails if there are any duplicated 285 * entries. 286 */ 287 int zap_join(objset_t *os, uint64_t fromobj, uint64_t intoobj, dmu_tx_t *tx); 288 289 /* Same as zap_join, but set the values to 'value'. */ 290 int zap_join_key(objset_t *os, uint64_t fromobj, uint64_t intoobj, 291 uint64_t value, dmu_tx_t *tx); 292 293 /* Same as zap_join, but add together any duplicated entries. */ 294 int zap_join_increment(objset_t *os, uint64_t fromobj, uint64_t intoobj, 295 dmu_tx_t *tx); 296 297 /* 298 * Manipulate entries where the name + value are the "same" (the name is 299 * a stringified version of the value). 300 */ 301 int zap_add_int(objset_t *os, uint64_t obj, uint64_t value, dmu_tx_t *tx); 302 int zap_remove_int(objset_t *os, uint64_t obj, uint64_t value, dmu_tx_t *tx); 303 int zap_lookup_int(objset_t *os, uint64_t obj, uint64_t value); 304 int zap_increment_int(objset_t *os, uint64_t obj, uint64_t key, int64_t delta, 305 dmu_tx_t *tx); 306 307 /* Here the key is an int and the value is a different int. */ 308 int zap_add_int_key(objset_t *os, uint64_t obj, 309 uint64_t key, uint64_t value, dmu_tx_t *tx); 310 int zap_update_int_key(objset_t *os, uint64_t obj, 311 uint64_t key, uint64_t value, dmu_tx_t *tx); 312 int zap_lookup_int_key(objset_t *os, uint64_t obj, 313 uint64_t key, uint64_t *valuep); 314 315 int zap_increment(objset_t *os, uint64_t obj, const char *name, int64_t delta, 316 dmu_tx_t *tx); 317 318 struct zap; 319 struct zap_leaf; 320 typedef struct zap_cursor { 321 /* This structure is opaque! */ 322 objset_t *zc_objset; 323 struct zap *zc_zap; 324 struct zap_leaf *zc_leaf; 325 uint64_t zc_zapobj; 326 uint64_t zc_serialized; 327 uint64_t zc_hash; 328 uint32_t zc_cd; 329 } zap_cursor_t; 330 331 typedef struct { 332 int za_integer_length; 333 /* 334 * za_normalization_conflict will be set if there are additional 335 * entries with this normalized form (eg, "foo" and "Foo"). 336 */ 337 boolean_t za_normalization_conflict; 338 uint64_t za_num_integers; 339 uint64_t za_first_integer; /* no sign extension for <8byte ints */ 340 char za_name[MAXNAMELEN]; 341 } zap_attribute_t; 342 343 /* 344 * The interface for listing all the attributes of a zapobj can be 345 * thought of as cursor moving down a list of the attributes one by 346 * one. The cookie returned by the zap_cursor_serialize routine is 347 * persistent across system calls (and across reboot, even). 348 */ 349 350 /* 351 * Initialize a zap cursor, pointing to the "first" attribute of the 352 * zapobj. You must _fini the cursor when you are done with it. 353 */ 354 void zap_cursor_init(zap_cursor_t *zc, objset_t *ds, uint64_t zapobj); 355 void zap_cursor_fini(zap_cursor_t *zc); 356 357 /* 358 * Get the attribute currently pointed to by the cursor. Returns 359 * ENOENT if at the end of the attributes. 360 */ 361 int zap_cursor_retrieve(zap_cursor_t *zc, zap_attribute_t *za); 362 363 /* 364 * Advance the cursor to the next attribute. 365 */ 366 void zap_cursor_advance(zap_cursor_t *zc); 367 368 /* 369 * Get a persistent cookie pointing to the current position of the zap 370 * cursor. The low 4 bits in the cookie are always zero, and thus can 371 * be used as to differentiate a serialized cookie from a different type 372 * of value. The cookie will be less than 2^32 as long as there are 373 * fewer than 2^22 (4.2 million) entries in the zap object. 374 */ 375 uint64_t zap_cursor_serialize(zap_cursor_t *zc); 376 377 /* 378 * Initialize a zap cursor pointing to the position recorded by 379 * zap_cursor_serialize (in the "serialized" argument). You can also 380 * use a "serialized" argument of 0 to start at the beginning of the 381 * zapobj (ie. zap_cursor_init_serialized(..., 0) is equivalent to 382 * zap_cursor_init(...).) 383 */ 384 void zap_cursor_init_serialized(zap_cursor_t *zc, objset_t *ds, 385 uint64_t zapobj, uint64_t serialized); 386 387 388 #define ZAP_HISTOGRAM_SIZE 10 389 390 typedef struct zap_stats { 391 /* 392 * Size of the pointer table (in number of entries). 393 * This is always a power of 2, or zero if it's a microzap. 394 * In general, it should be considerably greater than zs_num_leafs. 395 */ 396 uint64_t zs_ptrtbl_len; 397 398 uint64_t zs_blocksize; /* size of zap blocks */ 399 400 /* 401 * The number of blocks used. Note that some blocks may be 402 * wasted because old ptrtbl's and large name/value blocks are 403 * not reused. (Although their space is reclaimed, we don't 404 * reuse those offsets in the object.) 405 */ 406 uint64_t zs_num_blocks; 407 408 /* 409 * Pointer table values from zap_ptrtbl in the zap_phys_t 410 */ 411 uint64_t zs_ptrtbl_nextblk; /* next (larger) copy start block */ 412 uint64_t zs_ptrtbl_blks_copied; /* number source blocks copied */ 413 uint64_t zs_ptrtbl_zt_blk; /* starting block number */ 414 uint64_t zs_ptrtbl_zt_numblks; /* number of blocks */ 415 uint64_t zs_ptrtbl_zt_shift; /* bits to index it */ 416 417 /* 418 * Values of the other members of the zap_phys_t 419 */ 420 uint64_t zs_block_type; /* ZBT_HEADER */ 421 uint64_t zs_magic; /* ZAP_MAGIC */ 422 uint64_t zs_num_leafs; /* The number of leaf blocks */ 423 uint64_t zs_num_entries; /* The number of zap entries */ 424 uint64_t zs_salt; /* salt to stir into hash function */ 425 426 /* 427 * Histograms. For all histograms, the last index 428 * (ZAP_HISTOGRAM_SIZE-1) includes any values which are greater 429 * than what can be represented. For example 430 * zs_leafs_with_n5_entries[ZAP_HISTOGRAM_SIZE-1] is the number 431 * of leafs with more than 45 entries. 432 */ 433 434 /* 435 * zs_leafs_with_n_pointers[n] is the number of leafs with 436 * 2^n pointers to it. 437 */ 438 uint64_t zs_leafs_with_2n_pointers[ZAP_HISTOGRAM_SIZE]; 439 440 /* 441 * zs_leafs_with_n_entries[n] is the number of leafs with 442 * [n*5, (n+1)*5) entries. In the current implementation, there 443 * can be at most 55 entries in any block, but there may be 444 * fewer if the name or value is large, or the block is not 445 * completely full. 446 */ 447 uint64_t zs_blocks_with_n5_entries[ZAP_HISTOGRAM_SIZE]; 448 449 /* 450 * zs_leafs_n_tenths_full[n] is the number of leafs whose 451 * fullness is in the range [n/10, (n+1)/10). 452 */ 453 uint64_t zs_blocks_n_tenths_full[ZAP_HISTOGRAM_SIZE]; 454 455 /* 456 * zs_entries_using_n_chunks[n] is the number of entries which 457 * consume n 24-byte chunks. (Note, large names/values only use 458 * one chunk, but contribute to zs_num_blocks_large.) 459 */ 460 uint64_t zs_entries_using_n_chunks[ZAP_HISTOGRAM_SIZE]; 461 462 /* 463 * zs_buckets_with_n_entries[n] is the number of buckets (each 464 * leaf has 64 buckets) with n entries. 465 * zs_buckets_with_n_entries[1] should be very close to 466 * zs_num_entries. 467 */ 468 uint64_t zs_buckets_with_n_entries[ZAP_HISTOGRAM_SIZE]; 469 } zap_stats_t; 470 471 /* 472 * Get statistics about a ZAP object. Note: you need to be aware of the 473 * internal implementation of the ZAP to correctly interpret some of the 474 * statistics. This interface shouldn't be relied on unless you really 475 * know what you're doing. 476 */ 477 int zap_get_stats(objset_t *ds, uint64_t zapobj, zap_stats_t *zs); 478 479 #ifdef __cplusplus 480 } 481 #endif 482 483 #endif /* _SYS_ZAP_H */ 484