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 /* 23 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 24 * Copyright (c) 2012, 2018 by Delphix. All rights reserved. 25 * Copyright 2017 Nexenta Systems, Inc. 26 */ 27 28 #ifndef _SYS_ZAP_H 29 #define _SYS_ZAP_H 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 #include <sys/refcount.h> 86 87 #ifdef __cplusplus 88 extern "C" { 89 #endif 90 91 /* 92 * Specifies matching criteria for ZAP lookups. 93 * MT_NORMALIZE Use ZAP normalization flags, which can include both 94 * unicode normalization and case-insensitivity. 95 * MT_MATCH_CASE Do case-sensitive lookups even if MT_NORMALIZE is 96 * specified and ZAP normalization flags include 97 * U8_TEXTPREP_TOUPPER. 98 */ 99 typedef enum matchtype { 100 MT_NORMALIZE = 1 << 0, 101 MT_MATCH_CASE = 1 << 1, 102 } matchtype_t; 103 104 typedef enum zap_flags { 105 /* Use 64-bit hash value (serialized cursors will always use 64-bits) */ 106 ZAP_FLAG_HASH64 = 1 << 0, 107 /* Key is binary, not string (zap_add_uint64() can be used) */ 108 ZAP_FLAG_UINT64_KEY = 1 << 1, 109 /* 110 * First word of key (which must be an array of uint64) is 111 * already randomly distributed. 112 */ 113 ZAP_FLAG_PRE_HASHED_KEY = 1 << 2, 114 } zap_flags_t; 115 116 /* 117 * Create a new zapobj with no attributes and return its object number. 118 * 119 * dnodesize specifies the on-disk size of the dnode for the new zapobj. 120 * Valid values are multiples of 512 up to DNODE_MAX_SIZE. 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_dnsize(objset_t *ds, dmu_object_type_t ot, 125 dmu_object_type_t bonustype, int bonuslen, int dnodesize, dmu_tx_t *tx); 126 uint64_t zap_create_norm(objset_t *ds, int normflags, dmu_object_type_t ot, 127 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx); 128 uint64_t zap_create_norm_dnsize(objset_t *ds, int normflags, 129 dmu_object_type_t ot, dmu_object_type_t bonustype, int bonuslen, 130 int dnodesize, dmu_tx_t *tx); 131 uint64_t zap_create_flags(objset_t *os, int normflags, zap_flags_t flags, 132 dmu_object_type_t ot, int leaf_blockshift, int indirect_blockshift, 133 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx); 134 uint64_t zap_create_flags_dnsize(objset_t *os, int normflags, 135 zap_flags_t flags, dmu_object_type_t ot, int leaf_blockshift, 136 int indirect_blockshift, dmu_object_type_t bonustype, int bonuslen, 137 int dnodesize, dmu_tx_t *tx); 138 uint64_t zap_create_link(objset_t *os, dmu_object_type_t ot, 139 uint64_t parent_obj, const char *name, dmu_tx_t *tx); 140 uint64_t zap_create_link_dnsize(objset_t *os, dmu_object_type_t ot, 141 uint64_t parent_obj, const char *name, int dnodesize, dmu_tx_t *tx); 142 uint64_t zap_create_link_dnsize(objset_t *os, dmu_object_type_t ot, 143 uint64_t parent_obj, const char *name, int dnodesize, dmu_tx_t *tx); 144 145 /* 146 * Initialize an already-allocated object. 147 */ 148 void mzap_create_impl(objset_t *os, uint64_t obj, int normflags, 149 zap_flags_t flags, dmu_tx_t *tx); 150 151 /* 152 * Create a new zapobj with no attributes from the given (unallocated) 153 * object number. 154 */ 155 int zap_create_claim(objset_t *ds, uint64_t obj, dmu_object_type_t ot, 156 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx); 157 int zap_create_claim_dnsize(objset_t *ds, uint64_t obj, dmu_object_type_t ot, 158 dmu_object_type_t bonustype, int bonuslen, int dnodesize, dmu_tx_t *tx); 159 int zap_create_claim_norm(objset_t *ds, uint64_t obj, 160 int normflags, dmu_object_type_t ot, 161 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx); 162 int zap_create_claim_norm_dnsize(objset_t *ds, uint64_t obj, 163 int normflags, dmu_object_type_t ot, 164 dmu_object_type_t bonustype, int bonuslen, int dnodesize, dmu_tx_t *tx); 165 166 /* 167 * The zapobj passed in must be a valid ZAP object for all of the 168 * following routines. 169 */ 170 171 /* 172 * Destroy this zapobj and all its attributes. 173 * 174 * Frees the object number using dmu_object_free. 175 */ 176 int zap_destroy(objset_t *ds, uint64_t zapobj, dmu_tx_t *tx); 177 178 /* 179 * Manipulate attributes. 180 * 181 * 'integer_size' is in bytes, and must be 1, 2, 4, or 8. 182 */ 183 184 /* 185 * Retrieve the contents of the attribute with the given name. 186 * 187 * If the requested attribute does not exist, the call will fail and 188 * return ENOENT. 189 * 190 * If 'integer_size' is smaller than the attribute's integer size, the 191 * call will fail and return EINVAL. 192 * 193 * If 'integer_size' is equal to or larger than the attribute's integer 194 * size, the call will succeed and return 0. 195 * 196 * When converting to a larger integer size, the integers will be treated as 197 * unsigned (ie. no sign-extension will be performed). 198 * 199 * 'num_integers' is the length (in integers) of 'buf'. 200 * 201 * If the attribute is longer than the buffer, as many integers as will 202 * fit will be transferred to 'buf'. If the entire attribute was not 203 * transferred, the call will return EOVERFLOW. 204 */ 205 int zap_lookup(objset_t *ds, uint64_t zapobj, const char *name, 206 uint64_t integer_size, uint64_t num_integers, void *buf); 207 208 /* 209 * If rn_len is nonzero, realname will be set to the name of the found 210 * entry (which may be different from the requested name if matchtype is 211 * not MT_EXACT). 212 * 213 * If normalization_conflictp is not NULL, it will be set if there is 214 * another name with the same case/unicode normalized form. 215 */ 216 int zap_lookup_norm(objset_t *ds, uint64_t zapobj, const char *name, 217 uint64_t integer_size, uint64_t num_integers, void *buf, 218 matchtype_t mt, char *realname, int rn_len, 219 boolean_t *normalization_conflictp); 220 int zap_lookup_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key, 221 int key_numints, uint64_t integer_size, uint64_t num_integers, void *buf); 222 int zap_contains(objset_t *ds, uint64_t zapobj, const char *name); 223 int zap_prefetch_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key, 224 int key_numints); 225 int zap_lookup_by_dnode(dnode_t *dn, const char *name, 226 uint64_t integer_size, uint64_t num_integers, void *buf); 227 int zap_lookup_norm_by_dnode(dnode_t *dn, const char *name, 228 uint64_t integer_size, uint64_t num_integers, void *buf, 229 matchtype_t mt, char *realname, int rn_len, 230 boolean_t *ncp); 231 232 int zap_count_write_by_dnode(dnode_t *dn, const char *name, 233 int add, zfs_refcount_t *towrite, zfs_refcount_t *tooverwrite); 234 235 /* 236 * Create an attribute with the given name and value. 237 * 238 * If an attribute with the given name already exists, the call will 239 * fail and return EEXIST. 240 */ 241 int zap_add(objset_t *ds, uint64_t zapobj, const char *key, 242 int integer_size, uint64_t num_integers, 243 const void *val, dmu_tx_t *tx); 244 int zap_add_by_dnode(dnode_t *dn, const char *key, 245 int integer_size, uint64_t num_integers, 246 const void *val, dmu_tx_t *tx); 247 int zap_add_uint64(objset_t *ds, uint64_t zapobj, const uint64_t *key, 248 int key_numints, int integer_size, uint64_t num_integers, 249 const void *val, dmu_tx_t *tx); 250 251 /* 252 * Set the attribute with the given name to the given value. If an 253 * attribute with the given name does not exist, it will be created. If 254 * an attribute with the given name already exists, the previous value 255 * will be overwritten. The integer_size may be different from the 256 * existing attribute's integer size, in which case the attribute's 257 * integer size will be updated to the new value. 258 */ 259 int zap_update(objset_t *ds, uint64_t zapobj, const char *name, 260 int integer_size, uint64_t num_integers, const void *val, dmu_tx_t *tx); 261 int zap_update_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key, 262 int key_numints, 263 int integer_size, uint64_t num_integers, const void *val, dmu_tx_t *tx); 264 265 /* 266 * Get the length (in integers) and the integer size of the specified 267 * attribute. 268 * 269 * If the requested attribute does not exist, the call will fail and 270 * return ENOENT. 271 */ 272 int zap_length(objset_t *ds, uint64_t zapobj, const char *name, 273 uint64_t *integer_size, uint64_t *num_integers); 274 int zap_length_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key, 275 int key_numints, uint64_t *integer_size, uint64_t *num_integers); 276 277 /* 278 * Remove the specified attribute. 279 * 280 * If the specified attribute does not exist, the call will fail and 281 * return ENOENT. 282 */ 283 int zap_remove(objset_t *ds, uint64_t zapobj, const char *name, dmu_tx_t *tx); 284 int zap_remove_norm(objset_t *ds, uint64_t zapobj, const char *name, 285 matchtype_t mt, dmu_tx_t *tx); 286 int zap_remove_by_dnode(dnode_t *dn, const char *name, dmu_tx_t *tx); 287 int zap_remove_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key, 288 int key_numints, dmu_tx_t *tx); 289 290 /* 291 * Returns (in *count) the number of attributes in the specified zap 292 * object. 293 */ 294 int zap_count(objset_t *ds, uint64_t zapobj, uint64_t *count); 295 296 /* 297 * Returns (in name) the name of the entry whose (value & mask) 298 * (za_first_integer) is value, or ENOENT if not found. The string 299 * pointed to by name must be at least 256 bytes long. If mask==0, the 300 * match must be exact (ie, same as mask=-1ULL). 301 */ 302 int zap_value_search(objset_t *os, uint64_t zapobj, 303 uint64_t value, uint64_t mask, char *name); 304 305 /* 306 * Transfer all the entries from fromobj into intoobj. Only works on 307 * int_size=8 num_integers=1 values. Fails if there are any duplicated 308 * entries. 309 */ 310 int zap_join(objset_t *os, uint64_t fromobj, uint64_t intoobj, dmu_tx_t *tx); 311 312 /* Same as zap_join, but set the values to 'value'. */ 313 int zap_join_key(objset_t *os, uint64_t fromobj, uint64_t intoobj, 314 uint64_t value, dmu_tx_t *tx); 315 316 /* Same as zap_join, but add together any duplicated entries. */ 317 int zap_join_increment(objset_t *os, uint64_t fromobj, uint64_t intoobj, 318 dmu_tx_t *tx); 319 320 /* 321 * Manipulate entries where the name + value are the "same" (the name is 322 * a stringified version of the value). 323 */ 324 int zap_add_int(objset_t *os, uint64_t obj, uint64_t value, dmu_tx_t *tx); 325 int zap_remove_int(objset_t *os, uint64_t obj, uint64_t value, dmu_tx_t *tx); 326 int zap_lookup_int(objset_t *os, uint64_t obj, uint64_t value); 327 int zap_increment_int(objset_t *os, uint64_t obj, uint64_t key, int64_t delta, 328 dmu_tx_t *tx); 329 330 /* Here the key is an int and the value is a different int. */ 331 int zap_add_int_key(objset_t *os, uint64_t obj, 332 uint64_t key, uint64_t value, dmu_tx_t *tx); 333 int zap_update_int_key(objset_t *os, uint64_t obj, 334 uint64_t key, uint64_t value, dmu_tx_t *tx); 335 int zap_lookup_int_key(objset_t *os, uint64_t obj, 336 uint64_t key, uint64_t *valuep); 337 338 int zap_increment(objset_t *os, uint64_t obj, const char *name, int64_t delta, 339 dmu_tx_t *tx); 340 341 struct zap; 342 struct zap_leaf; 343 typedef struct zap_cursor { 344 /* This structure is opaque! */ 345 objset_t *zc_objset; 346 struct zap *zc_zap; 347 struct zap_leaf *zc_leaf; 348 uint64_t zc_zapobj; 349 uint64_t zc_serialized; 350 uint64_t zc_hash; 351 uint32_t zc_cd; 352 boolean_t zc_prefetch; 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 */ 364 char za_name[ZAP_MAXNAMELEN]; 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_init_noprefetch(zap_cursor_t *zc, objset_t *os, 380 uint64_t zapobj); 381 void zap_cursor_fini(zap_cursor_t *zc); 382 383 /* 384 * Get the attribute currently pointed to by the cursor. Returns 385 * ENOENT if at the end of the attributes. 386 */ 387 int zap_cursor_retrieve(zap_cursor_t *zc, zap_attribute_t *za); 388 389 /* 390 * Advance the cursor to the next attribute. 391 */ 392 void zap_cursor_advance(zap_cursor_t *zc); 393 394 /* 395 * Get a persistent cookie pointing to the current position of the zap 396 * cursor. The low 4 bits in the cookie are always zero, and thus can 397 * be used as to differentiate a serialized cookie from a different type 398 * of value. The cookie will be less than 2^32 as long as there are 399 * fewer than 2^22 (4.2 million) entries in the zap object. 400 */ 401 uint64_t zap_cursor_serialize(zap_cursor_t *zc); 402 403 /* 404 * Advance the cursor to the attribute having the given key. 405 */ 406 int zap_cursor_move_to_key(zap_cursor_t *zc, const char *name, matchtype_t mt); 407 408 /* 409 * Initialize a zap cursor pointing to the position recorded by 410 * zap_cursor_serialize (in the "serialized" argument). You can also 411 * use a "serialized" argument of 0 to start at the beginning of the 412 * zapobj (ie. zap_cursor_init_serialized(..., 0) is equivalent to 413 * zap_cursor_init(...).) 414 */ 415 void zap_cursor_init_serialized(zap_cursor_t *zc, objset_t *ds, 416 uint64_t zapobj, uint64_t serialized); 417 418 419 #define ZAP_HISTOGRAM_SIZE 10 420 421 typedef struct zap_stats { 422 /* 423 * Size of the pointer table (in number of entries). 424 * This is always a power of 2, or zero if it's a microzap. 425 * In general, it should be considerably greater than zs_num_leafs. 426 */ 427 uint64_t zs_ptrtbl_len; 428 429 uint64_t zs_blocksize; /* size of zap blocks */ 430 431 /* 432 * The number of blocks used. Note that some blocks may be 433 * wasted because old ptrtbl's and large name/value blocks are 434 * not reused. (Although their space is reclaimed, we don't 435 * reuse those offsets in the object.) 436 */ 437 uint64_t zs_num_blocks; 438 439 /* 440 * Pointer table values from zap_ptrtbl in the zap_phys_t 441 */ 442 uint64_t zs_ptrtbl_nextblk; /* next (larger) copy start block */ 443 uint64_t zs_ptrtbl_blks_copied; /* number source blocks copied */ 444 uint64_t zs_ptrtbl_zt_blk; /* starting block number */ 445 uint64_t zs_ptrtbl_zt_numblks; /* number of blocks */ 446 uint64_t zs_ptrtbl_zt_shift; /* bits to index it */ 447 448 /* 449 * Values of the other members of the zap_phys_t 450 */ 451 uint64_t zs_block_type; /* ZBT_HEADER */ 452 uint64_t zs_magic; /* ZAP_MAGIC */ 453 uint64_t zs_num_leafs; /* The number of leaf blocks */ 454 uint64_t zs_num_entries; /* The number of zap entries */ 455 uint64_t zs_salt; /* salt to stir into hash function */ 456 457 /* 458 * Histograms. For all histograms, the last index 459 * (ZAP_HISTOGRAM_SIZE-1) includes any values which are greater 460 * than what can be represented. For example 461 * zs_leafs_with_n5_entries[ZAP_HISTOGRAM_SIZE-1] is the number 462 * of leafs with more than 45 entries. 463 */ 464 465 /* 466 * zs_leafs_with_n_pointers[n] is the number of leafs with 467 * 2^n pointers to it. 468 */ 469 uint64_t zs_leafs_with_2n_pointers[ZAP_HISTOGRAM_SIZE]; 470 471 /* 472 * zs_leafs_with_n_entries[n] is the number of leafs with 473 * [n*5, (n+1)*5) entries. In the current implementation, there 474 * can be at most 55 entries in any block, but there may be 475 * fewer if the name or value is large, or the block is not 476 * completely full. 477 */ 478 uint64_t zs_blocks_with_n5_entries[ZAP_HISTOGRAM_SIZE]; 479 480 /* 481 * zs_leafs_n_tenths_full[n] is the number of leafs whose 482 * fullness is in the range [n/10, (n+1)/10). 483 */ 484 uint64_t zs_blocks_n_tenths_full[ZAP_HISTOGRAM_SIZE]; 485 486 /* 487 * zs_entries_using_n_chunks[n] is the number of entries which 488 * consume n 24-byte chunks. (Note, large names/values only use 489 * one chunk, but contribute to zs_num_blocks_large.) 490 */ 491 uint64_t zs_entries_using_n_chunks[ZAP_HISTOGRAM_SIZE]; 492 493 /* 494 * zs_buckets_with_n_entries[n] is the number of buckets (each 495 * leaf has 64 buckets) with n entries. 496 * zs_buckets_with_n_entries[1] should be very close to 497 * zs_num_entries. 498 */ 499 uint64_t zs_buckets_with_n_entries[ZAP_HISTOGRAM_SIZE]; 500 } zap_stats_t; 501 502 /* 503 * Get statistics about a ZAP object. Note: you need to be aware of the 504 * internal implementation of the ZAP to correctly interpret some of the 505 * statistics. This interface shouldn't be relied on unless you really 506 * know what you're doing. 507 */ 508 int zap_get_stats(objset_t *ds, uint64_t zapobj, zap_stats_t *zs); 509 510 #ifdef __cplusplus 511 } 512 #endif 513 514 #endif /* _SYS_ZAP_H */ 515