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