zap_leaf.h revision 277585
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 */ 24 25#ifndef _SYS_ZAP_LEAF_H 26#define _SYS_ZAP_LEAF_H 27 28#include <sys/zap.h> 29 30#ifdef __cplusplus 31extern "C" { 32#endif 33 34struct zap; 35struct zap_name; 36struct zap_stats; 37 38#define ZAP_LEAF_MAGIC 0x2AB1EAF 39 40/* chunk size = 24 bytes */ 41#define ZAP_LEAF_CHUNKSIZE 24 42 43/* 44 * The amount of space available for chunks is: 45 * block size (1<<l->l_bs) - hash entry size (2) * number of hash 46 * entries - header space (2*chunksize) 47 */ 48#define ZAP_LEAF_NUMCHUNKS(l) \ 49 (((1<<(l)->l_bs) - 2*ZAP_LEAF_HASH_NUMENTRIES(l)) / \ 50 ZAP_LEAF_CHUNKSIZE - 2) 51 52/* 53 * The amount of space within the chunk available for the array is: 54 * chunk size - space for type (1) - space for next pointer (2) 55 */ 56#define ZAP_LEAF_ARRAY_BYTES (ZAP_LEAF_CHUNKSIZE - 3) 57 58#define ZAP_LEAF_ARRAY_NCHUNKS(bytes) \ 59 (((bytes)+ZAP_LEAF_ARRAY_BYTES-1)/ZAP_LEAF_ARRAY_BYTES) 60 61/* 62 * Low water mark: when there are only this many chunks free, start 63 * growing the ptrtbl. Ideally, this should be larger than a 64 * "reasonably-sized" entry. 20 chunks is more than enough for the 65 * largest directory entry (MAXNAMELEN (256) byte name, 8-byte value), 66 * while still being only around 3% for 16k blocks. 67 */ 68#define ZAP_LEAF_LOW_WATER (20) 69 70/* 71 * The leaf hash table has block size / 2^5 (32) number of entries, 72 * which should be more than enough for the maximum number of entries, 73 * which is less than block size / CHUNKSIZE (24) / minimum number of 74 * chunks per entry (3). 75 */ 76#define ZAP_LEAF_HASH_SHIFT(l) ((l)->l_bs - 5) 77#define ZAP_LEAF_HASH_NUMENTRIES(l) (1 << ZAP_LEAF_HASH_SHIFT(l)) 78 79/* 80 * The chunks start immediately after the hash table. The end of the 81 * hash table is at l_hash + HASH_NUMENTRIES, which we simply cast to a 82 * chunk_t. 83 */ 84#define ZAP_LEAF_CHUNK(l, idx) \ 85 ((zap_leaf_chunk_t *) \ 86 (zap_leaf_phys(l)->l_hash + ZAP_LEAF_HASH_NUMENTRIES(l)))[idx] 87#define ZAP_LEAF_ENTRY(l, idx) (&ZAP_LEAF_CHUNK(l, idx).l_entry) 88 89typedef enum zap_chunk_type { 90 ZAP_CHUNK_FREE = 253, 91 ZAP_CHUNK_ENTRY = 252, 92 ZAP_CHUNK_ARRAY = 251, 93 ZAP_CHUNK_TYPE_MAX = 250 94} zap_chunk_type_t; 95 96#define ZLF_ENTRIES_CDSORTED (1<<0) 97 98/* 99 * TAKE NOTE: 100 * If zap_leaf_phys_t is modified, zap_leaf_byteswap() must be modified. 101 */ 102typedef struct zap_leaf_phys { 103 struct zap_leaf_header { 104 /* Public to ZAP */ 105 uint64_t lh_block_type; /* ZBT_LEAF */ 106 uint64_t lh_pad1; 107 uint64_t lh_prefix; /* hash prefix of this leaf */ 108 uint32_t lh_magic; /* ZAP_LEAF_MAGIC */ 109 uint16_t lh_nfree; /* number free chunks */ 110 uint16_t lh_nentries; /* number of entries */ 111 uint16_t lh_prefix_len; /* num bits used to id this */ 112 113 /* Private to zap_leaf */ 114 uint16_t lh_freelist; /* chunk head of free list */ 115 uint8_t lh_flags; /* ZLF_* flags */ 116 uint8_t lh_pad2[11]; 117 } l_hdr; /* 2 24-byte chunks */ 118 119 /* 120 * The header is followed by a hash table with 121 * ZAP_LEAF_HASH_NUMENTRIES(zap) entries. The hash table is 122 * followed by an array of ZAP_LEAF_NUMCHUNKS(zap) 123 * zap_leaf_chunk structures. These structures are accessed 124 * with the ZAP_LEAF_CHUNK() macro. 125 */ 126 127 uint16_t l_hash[1]; 128} zap_leaf_phys_t; 129 130typedef union zap_leaf_chunk { 131 struct zap_leaf_entry { 132 uint8_t le_type; /* always ZAP_CHUNK_ENTRY */ 133 uint8_t le_value_intlen; /* size of value's ints */ 134 uint16_t le_next; /* next entry in hash chain */ 135 uint16_t le_name_chunk; /* first chunk of the name */ 136 uint16_t le_name_numints; /* ints in name (incl null) */ 137 uint16_t le_value_chunk; /* first chunk of the value */ 138 uint16_t le_value_numints; /* value length in ints */ 139 uint32_t le_cd; /* collision differentiator */ 140 uint64_t le_hash; /* hash value of the name */ 141 } l_entry; 142 struct zap_leaf_array { 143 uint8_t la_type; /* always ZAP_CHUNK_ARRAY */ 144 uint8_t la_array[ZAP_LEAF_ARRAY_BYTES]; 145 uint16_t la_next; /* next blk or CHAIN_END */ 146 } l_array; 147 struct zap_leaf_free { 148 uint8_t lf_type; /* always ZAP_CHUNK_FREE */ 149 uint8_t lf_pad[ZAP_LEAF_ARRAY_BYTES]; 150 uint16_t lf_next; /* next in free list, or CHAIN_END */ 151 } l_free; 152} zap_leaf_chunk_t; 153 154typedef struct zap_leaf { 155 krwlock_t l_rwlock; 156 uint64_t l_blkid; /* 1<<ZAP_BLOCK_SHIFT byte block off */ 157 int l_bs; /* block size shift */ 158 dmu_buf_t *l_dbuf; 159} zap_leaf_t; 160 161inline zap_leaf_phys_t * 162zap_leaf_phys(zap_leaf_t *l) 163{ 164 return (l->l_dbuf->db_data); 165} 166 167typedef struct zap_entry_handle { 168 /* Set by zap_leaf and public to ZAP */ 169 uint64_t zeh_num_integers; 170 uint64_t zeh_hash; 171 uint32_t zeh_cd; 172 uint8_t zeh_integer_size; 173 174 /* Private to zap_leaf */ 175 uint16_t zeh_fakechunk; 176 uint16_t *zeh_chunkp; 177 zap_leaf_t *zeh_leaf; 178} zap_entry_handle_t; 179 180/* 181 * Return a handle to the named entry, or ENOENT if not found. The hash 182 * value must equal zap_hash(name). 183 */ 184extern int zap_leaf_lookup(zap_leaf_t *l, 185 struct zap_name *zn, zap_entry_handle_t *zeh); 186 187/* 188 * Return a handle to the entry with this hash+cd, or the entry with the 189 * next closest hash+cd. 190 */ 191extern int zap_leaf_lookup_closest(zap_leaf_t *l, 192 uint64_t hash, uint32_t cd, zap_entry_handle_t *zeh); 193 194/* 195 * Read the first num_integers in the attribute. Integer size 196 * conversion will be done without sign extension. Return EINVAL if 197 * integer_size is too small. Return EOVERFLOW if there are more than 198 * num_integers in the attribute. 199 */ 200extern int zap_entry_read(const zap_entry_handle_t *zeh, 201 uint8_t integer_size, uint64_t num_integers, void *buf); 202 203extern int zap_entry_read_name(struct zap *zap, const zap_entry_handle_t *zeh, 204 uint16_t buflen, char *buf); 205 206/* 207 * Replace the value of an existing entry. 208 * 209 * May fail if it runs out of space (ENOSPC). 210 */ 211extern int zap_entry_update(zap_entry_handle_t *zeh, 212 uint8_t integer_size, uint64_t num_integers, const void *buf); 213 214/* 215 * Remove an entry. 216 */ 217extern void zap_entry_remove(zap_entry_handle_t *zeh); 218 219/* 220 * Create an entry. An equal entry must not exist, and this entry must 221 * belong in this leaf (according to its hash value). Fills in the 222 * entry handle on success. Returns 0 on success or ENOSPC on failure. 223 */ 224extern int zap_entry_create(zap_leaf_t *l, struct zap_name *zn, uint32_t cd, 225 uint8_t integer_size, uint64_t num_integers, const void *buf, 226 zap_entry_handle_t *zeh); 227 228/* Determine whether there is another entry with the same normalized form. */ 229extern boolean_t zap_entry_normalization_conflict(zap_entry_handle_t *zeh, 230 struct zap_name *zn, const char *name, struct zap *zap); 231 232/* 233 * Other stuff. 234 */ 235 236extern void zap_leaf_init(zap_leaf_t *l, boolean_t sort); 237extern void zap_leaf_byteswap(zap_leaf_phys_t *buf, int len); 238extern void zap_leaf_split(zap_leaf_t *l, zap_leaf_t *nl, boolean_t sort); 239extern void zap_leaf_stats(struct zap *zap, zap_leaf_t *l, 240 struct zap_stats *zs); 241 242#ifdef __cplusplus 243} 244#endif 245 246#endif /* _SYS_ZAP_LEAF_H */ 247