zap_leaf.h revision 288549
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) 2014 Spectra Logic Corporation, All rights reserved. 24 */ 25 26#ifndef _SYS_ZAP_LEAF_H 27#define _SYS_ZAP_LEAF_H 28 29#include <sys/zap.h> 30 31#ifdef __cplusplus 32extern "C" { 33#endif 34 35struct zap; 36struct zap_name; 37struct zap_stats; 38 39#define ZAP_LEAF_MAGIC 0x2AB1EAF 40 41/* chunk size = 24 bytes */ 42#define ZAP_LEAF_CHUNKSIZE 24 43 44/* 45 * The amount of space available for chunks is: 46 * block size (1<<l->l_bs) - hash entry size (2) * number of hash 47 * entries - header space (2*chunksize) 48 */ 49#define ZAP_LEAF_NUMCHUNKS(l) \ 50 (((1<<(l)->l_bs) - 2*ZAP_LEAF_HASH_NUMENTRIES(l)) / \ 51 ZAP_LEAF_CHUNKSIZE - 2) 52 53/* 54 * The amount of space within the chunk available for the array is: 55 * chunk size - space for type (1) - space for next pointer (2) 56 */ 57#define ZAP_LEAF_ARRAY_BYTES (ZAP_LEAF_CHUNKSIZE - 3) 58 59#define ZAP_LEAF_ARRAY_NCHUNKS(bytes) \ 60 (((bytes)+ZAP_LEAF_ARRAY_BYTES-1)/ZAP_LEAF_ARRAY_BYTES) 61 62/* 63 * Low water mark: when there are only this many chunks free, start 64 * growing the ptrtbl. Ideally, this should be larger than a 65 * "reasonably-sized" entry. 20 chunks is more than enough for the 66 * largest directory entry (MAXNAMELEN (256) byte name, 8-byte value), 67 * while still being only around 3% for 16k blocks. 68 */ 69#define ZAP_LEAF_LOW_WATER (20) 70 71/* 72 * The leaf hash table has block size / 2^5 (32) number of entries, 73 * which should be more than enough for the maximum number of entries, 74 * which is less than block size / CHUNKSIZE (24) / minimum number of 75 * chunks per entry (3). 76 */ 77#define ZAP_LEAF_HASH_SHIFT(l) ((l)->l_bs - 5) 78#define ZAP_LEAF_HASH_NUMENTRIES(l) (1 << ZAP_LEAF_HASH_SHIFT(l)) 79 80/* 81 * The chunks start immediately after the hash table. The end of the 82 * hash table is at l_hash + HASH_NUMENTRIES, which we simply cast to a 83 * chunk_t. 84 */ 85#define ZAP_LEAF_CHUNK(l, idx) \ 86 ((zap_leaf_chunk_t *) \ 87 (zap_leaf_phys(l)->l_hash + ZAP_LEAF_HASH_NUMENTRIES(l)))[idx] 88#define ZAP_LEAF_ENTRY(l, idx) (&ZAP_LEAF_CHUNK(l, idx).l_entry) 89 90typedef enum zap_chunk_type { 91 ZAP_CHUNK_FREE = 253, 92 ZAP_CHUNK_ENTRY = 252, 93 ZAP_CHUNK_ARRAY = 251, 94 ZAP_CHUNK_TYPE_MAX = 250 95} zap_chunk_type_t; 96 97#define ZLF_ENTRIES_CDSORTED (1<<0) 98 99/* 100 * TAKE NOTE: 101 * If zap_leaf_phys_t is modified, zap_leaf_byteswap() must be modified. 102 */ 103typedef struct zap_leaf_phys { 104 struct zap_leaf_header { 105 /* Public to ZAP */ 106 uint64_t lh_block_type; /* ZBT_LEAF */ 107 uint64_t lh_pad1; 108 uint64_t lh_prefix; /* hash prefix of this leaf */ 109 uint32_t lh_magic; /* ZAP_LEAF_MAGIC */ 110 uint16_t lh_nfree; /* number free chunks */ 111 uint16_t lh_nentries; /* number of entries */ 112 uint16_t lh_prefix_len; /* num bits used to id this */ 113 114 /* Private to zap_leaf */ 115 uint16_t lh_freelist; /* chunk head of free list */ 116 uint8_t lh_flags; /* ZLF_* flags */ 117 uint8_t lh_pad2[11]; 118 } l_hdr; /* 2 24-byte chunks */ 119 120 /* 121 * The header is followed by a hash table with 122 * ZAP_LEAF_HASH_NUMENTRIES(zap) entries. The hash table is 123 * followed by an array of ZAP_LEAF_NUMCHUNKS(zap) 124 * zap_leaf_chunk structures. These structures are accessed 125 * with the ZAP_LEAF_CHUNK() macro. 126 */ 127 128 uint16_t l_hash[1]; 129} zap_leaf_phys_t; 130 131typedef union zap_leaf_chunk { 132 struct zap_leaf_entry { 133 uint8_t le_type; /* always ZAP_CHUNK_ENTRY */ 134 uint8_t le_value_intlen; /* size of value's ints */ 135 uint16_t le_next; /* next entry in hash chain */ 136 uint16_t le_name_chunk; /* first chunk of the name */ 137 uint16_t le_name_numints; /* ints in name (incl null) */ 138 uint16_t le_value_chunk; /* first chunk of the value */ 139 uint16_t le_value_numints; /* value length in ints */ 140 uint32_t le_cd; /* collision differentiator */ 141 uint64_t le_hash; /* hash value of the name */ 142 } l_entry; 143 struct zap_leaf_array { 144 uint8_t la_type; /* always ZAP_CHUNK_ARRAY */ 145 uint8_t la_array[ZAP_LEAF_ARRAY_BYTES]; 146 uint16_t la_next; /* next blk or CHAIN_END */ 147 } l_array; 148 struct zap_leaf_free { 149 uint8_t lf_type; /* always ZAP_CHUNK_FREE */ 150 uint8_t lf_pad[ZAP_LEAF_ARRAY_BYTES]; 151 uint16_t lf_next; /* next in free list, or CHAIN_END */ 152 } l_free; 153} zap_leaf_chunk_t; 154 155typedef struct zap_leaf { 156 dmu_buf_user_t l_dbu; 157 krwlock_t l_rwlock; 158 uint64_t l_blkid; /* 1<<ZAP_BLOCK_SHIFT byte block off */ 159 int l_bs; /* block size shift */ 160 dmu_buf_t *l_dbuf; 161} zap_leaf_t; 162 163inline zap_leaf_phys_t * 164zap_leaf_phys(zap_leaf_t *l) 165{ 166 return (l->l_dbuf->db_data); 167} 168 169typedef struct zap_entry_handle { 170 /* Set by zap_leaf and public to ZAP */ 171 uint64_t zeh_num_integers; 172 uint64_t zeh_hash; 173 uint32_t zeh_cd; 174 uint8_t zeh_integer_size; 175 176 /* Private to zap_leaf */ 177 uint16_t zeh_fakechunk; 178 uint16_t *zeh_chunkp; 179 zap_leaf_t *zeh_leaf; 180} zap_entry_handle_t; 181 182/* 183 * Return a handle to the named entry, or ENOENT if not found. The hash 184 * value must equal zap_hash(name). 185 */ 186extern int zap_leaf_lookup(zap_leaf_t *l, 187 struct zap_name *zn, zap_entry_handle_t *zeh); 188 189/* 190 * Return a handle to the entry with this hash+cd, or the entry with the 191 * next closest hash+cd. 192 */ 193extern int zap_leaf_lookup_closest(zap_leaf_t *l, 194 uint64_t hash, uint32_t cd, zap_entry_handle_t *zeh); 195 196/* 197 * Read the first num_integers in the attribute. Integer size 198 * conversion will be done without sign extension. Return EINVAL if 199 * integer_size is too small. Return EOVERFLOW if there are more than 200 * num_integers in the attribute. 201 */ 202extern int zap_entry_read(const zap_entry_handle_t *zeh, 203 uint8_t integer_size, uint64_t num_integers, void *buf); 204 205extern int zap_entry_read_name(struct zap *zap, const zap_entry_handle_t *zeh, 206 uint16_t buflen, char *buf); 207 208/* 209 * Replace the value of an existing entry. 210 * 211 * May fail if it runs out of space (ENOSPC). 212 */ 213extern int zap_entry_update(zap_entry_handle_t *zeh, 214 uint8_t integer_size, uint64_t num_integers, const void *buf); 215 216/* 217 * Remove an entry. 218 */ 219extern void zap_entry_remove(zap_entry_handle_t *zeh); 220 221/* 222 * Create an entry. An equal entry must not exist, and this entry must 223 * belong in this leaf (according to its hash value). Fills in the 224 * entry handle on success. Returns 0 on success or ENOSPC on failure. 225 */ 226extern int zap_entry_create(zap_leaf_t *l, struct zap_name *zn, uint32_t cd, 227 uint8_t integer_size, uint64_t num_integers, const void *buf, 228 zap_entry_handle_t *zeh); 229 230/* Determine whether there is another entry with the same normalized form. */ 231extern boolean_t zap_entry_normalization_conflict(zap_entry_handle_t *zeh, 232 struct zap_name *zn, const char *name, struct zap *zap); 233 234/* 235 * Other stuff. 236 */ 237 238extern void zap_leaf_init(zap_leaf_t *l, boolean_t sort); 239extern void zap_leaf_byteswap(zap_leaf_phys_t *buf, int len); 240extern void zap_leaf_split(zap_leaf_t *l, zap_leaf_t *nl, boolean_t sort); 241extern void zap_leaf_stats(struct zap *zap, zap_leaf_t *l, 242 struct zap_stats *zs); 243 244#ifdef __cplusplus 245} 246#endif 247 248#endif /* _SYS_ZAP_LEAF_H */ 249