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 2006 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 #ifndef _SYS_ZAP_LEAF_H 27 #define _SYS_ZAP_LEAF_H 28 29 #pragma ident "%Z%%M% %I% %E% SMI" 30 31 #ifdef __cplusplus 32 extern "C" { 33 #endif 34 35 struct zap; 36 37 #define ZAP_LEAF_MAGIC 0x2AB1EAF 38 39 /* chunk size = 24 bytes */ 40 #define ZAP_LEAF_CHUNKSIZE 24 41 42 /* 43 * The amount of space available for chunks is: 44 * block size (1<<l->l_bs) - hash entry size (2) * number of hash 45 * entries - header space (2*chunksize) 46 */ 47 #define ZAP_LEAF_NUMCHUNKS(l) \ 48 (((1<<(l)->l_bs) - 2*ZAP_LEAF_HASH_NUMENTRIES(l)) / \ 49 ZAP_LEAF_CHUNKSIZE - 2) 50 51 /* 52 * The amount of space within the chunk available for the array is: 53 * chunk size - space for type (1) - space for next pointer (2) 54 */ 55 #define ZAP_LEAF_ARRAY_BYTES (ZAP_LEAF_CHUNKSIZE - 3) 56 57 /* 58 * The leaf hash table has block size / 2^5 (32) number of entries, 59 * which should be more than enough for the maximum number of entries, 60 * which is less than block size / CHUNKSIZE (24) / minimum number of 61 * chunks per entry (3). 62 */ 63 #define ZAP_LEAF_HASH_SHIFT(l) ((l)->l_bs - 5) 64 #define ZAP_LEAF_HASH_NUMENTRIES(l) (1 << ZAP_LEAF_HASH_SHIFT(l)) 65 66 /* 67 * The chunks start immediately after the hash table. The end of the 68 * hash table is at l_hash + HASH_NUMENTRIES, which we simply cast to a 69 * chunk_t. 70 */ 71 #define ZAP_LEAF_CHUNK(l, idx) \ 72 ((zap_leaf_chunk_t *) \ 73 ((l)->l_phys->l_hash + ZAP_LEAF_HASH_NUMENTRIES(l)))[idx] 74 #define ZAP_LEAF_ENTRY(l, idx) (&ZAP_LEAF_CHUNK(l, idx).l_entry) 75 76 typedef enum zap_chunk_type { 77 ZAP_CHUNK_FREE = 253, 78 ZAP_CHUNK_ENTRY = 252, 79 ZAP_CHUNK_ARRAY = 251, 80 ZAP_CHUNK_TYPE_MAX = 250 81 } zap_chunk_type_t; 82 83 /* 84 * TAKE NOTE: 85 * If zap_leaf_phys_t is modified, zap_leaf_byteswap() must be modified. 86 */ 87 typedef struct zap_leaf_phys { 88 struct zap_leaf_header { 89 uint64_t lhr_block_type; /* ZBT_LEAF */ 90 uint64_t lhr_next; /* next block in leaf chain */ 91 uint64_t lhr_prefix; 92 uint32_t lhr_magic; /* ZAP_LEAF_MAGIC */ 93 uint16_t lhr_nfree; /* number free chunks */ 94 uint16_t lhr_nentries; /* number of entries */ 95 uint16_t lhr_prefix_len; 96 97 #define lh_block_type l_phys->l_hdr.lhr_block_type 98 #define lh_magic l_phys->l_hdr.lhr_magic 99 #define lh_next l_phys->l_hdr.lhr_next 100 #define lh_prefix l_phys->l_hdr.lhr_prefix 101 #define lh_nfree l_phys->l_hdr.lhr_nfree 102 #define lh_prefix_len l_phys->l_hdr.lhr_prefix_len 103 #define lh_nentries l_phys->l_hdr.lhr_nentries 104 105 /* above is accessable to zap, below is zap_leaf private */ 106 107 uint16_t lh_freelist; /* chunk head of free list */ 108 uint8_t lh_pad2[12]; 109 } l_hdr; /* 2 24-byte chunks */ 110 111 /* 112 * The header is followed by a hash table with 113 * ZAP_LEAF_HASH_NUMENTRIES(zap) entries. The hash table is 114 * followed by an array of ZAP_LEAF_NUMCHUNKS(zap) 115 * zap_leaf_chunk structures. These structures are accessed 116 * with the ZAP_LEAF_CHUNK() macro. 117 */ 118 119 uint16_t l_hash[1]; 120 } zap_leaf_phys_t; 121 122 typedef union zap_leaf_chunk { 123 struct zap_leaf_entry { 124 uint8_t le_type; /* always ZAP_CHUNK_ENTRY */ 125 uint8_t le_int_size; /* size of ints */ 126 uint16_t le_next; /* next entry in hash chain */ 127 uint16_t le_name_chunk; /* first chunk of the name */ 128 uint16_t le_name_length; /* bytes in name, incl null */ 129 uint16_t le_value_chunk; /* first chunk of the value */ 130 uint16_t le_value_length; /* value length in ints */ 131 uint32_t le_cd; /* collision differentiator */ 132 uint64_t le_hash; /* hash value of the name */ 133 } l_entry; 134 struct zap_leaf_array { 135 uint8_t la_type; /* always ZAP_CHUNK_ARRAY */ 136 uint8_t la_array[ZAP_LEAF_ARRAY_BYTES]; 137 uint16_t la_next; /* next blk or CHAIN_END */ 138 } l_array; 139 struct zap_leaf_free { 140 uint8_t lf_type; /* always ZAP_CHUNK_FREE */ 141 uint8_t lf_pad[ZAP_LEAF_ARRAY_BYTES]; 142 uint16_t lf_next; /* next in free list, or CHAIN_END */ 143 } l_free; 144 } zap_leaf_chunk_t; 145 146 typedef struct zap_leaf { 147 krwlock_t l_rwlock; /* only used on head of chain */ 148 uint64_t l_blkid; /* 1<<ZAP_BLOCK_SHIFT byte block off */ 149 int l_bs; /* block size shift */ 150 struct zap_leaf *l_next; /* next in chain */ 151 dmu_buf_t *l_dbuf; 152 zap_leaf_phys_t *l_phys; 153 } zap_leaf_t; 154 155 156 typedef struct zap_entry_handle { 157 /* below is set by zap_leaf.c and is public to zap.c */ 158 uint64_t zeh_num_integers; 159 uint64_t zeh_hash; 160 uint32_t zeh_cd; 161 uint8_t zeh_integer_size; 162 163 /* below is private to zap_leaf.c */ 164 uint16_t zeh_fakechunk; 165 uint16_t *zeh_chunkp; 166 zap_leaf_t *zeh_head_leaf; 167 zap_leaf_t *zeh_found_leaf; 168 } zap_entry_handle_t; 169 170 /* 171 * Return a handle to the named entry, or ENOENT if not found. The hash 172 * value must equal zap_hash(name). 173 */ 174 extern int zap_leaf_lookup(zap_leaf_t *l, 175 const char *name, uint64_t h, zap_entry_handle_t *zeh); 176 177 /* 178 * Return a handle to the entry with this hash+cd, or the entry with the 179 * next closest hash+cd. 180 */ 181 extern int zap_leaf_lookup_closest(zap_leaf_t *l, 182 uint64_t hash, uint32_t cd, zap_entry_handle_t *zeh); 183 184 /* 185 * Read the first num_integers in the attribute. Integer size 186 * conversion will be done without sign extension. Return EINVAL if 187 * integer_size is too small. Return EOVERFLOW if there are more than 188 * num_integers in the attribute. 189 */ 190 extern int zap_entry_read(const zap_entry_handle_t *zeh, 191 uint8_t integer_size, uint64_t num_integers, void *buf); 192 193 extern int zap_entry_read_name(const zap_entry_handle_t *zeh, 194 uint16_t buflen, char *buf); 195 196 /* 197 * Replace the value of an existing entry. 198 * 199 * zap_entry_update may fail if it runs out of space (ENOSPC). 200 */ 201 extern int zap_entry_update(zap_entry_handle_t *zeh, 202 uint8_t integer_size, uint64_t num_integers, const void *buf); 203 204 /* 205 * Remove an entry. 206 */ 207 extern void zap_entry_remove(zap_entry_handle_t *zeh); 208 209 /* 210 * Create an entry. An equal entry must not exist, and this entry must 211 * belong in this leaf (according to its hash value). Fills in the 212 * entry handle on success. Returns 0 on success or ENOSPC on failure. 213 */ 214 extern int zap_entry_create(zap_leaf_t *l, 215 const char *name, uint64_t h, uint32_t cd, 216 uint8_t integer_size, uint64_t num_integers, const void *buf, 217 zap_entry_handle_t *zeh); 218 219 /* 220 * Other stuff. 221 */ 222 223 extern void zap_leaf_init(zap_leaf_t *l); 224 extern void zap_leaf_byteswap(zap_leaf_phys_t *buf, int len); 225 226 extern zap_leaf_t *zap_leaf_split(struct zap *zap, zap_leaf_t *l, dmu_tx_t *tx); 227 228 extern int zap_leaf_merge(zap_leaf_t *l, zap_leaf_t *sibling); 229 230 extern zap_leaf_t *zap_leaf_chainmore(zap_leaf_t *l, zap_leaf_t *nl); 231 232 extern int zap_leaf_advance(zap_leaf_t *l, zap_cursor_t *zc); 233 234 extern void zap_stats_leaf(zap_t *zap, zap_leaf_t *l, zap_stats_t *zs); 235 236 #ifdef __cplusplus 237 } 238 #endif 239 240 #endif /* _SYS_ZAP_LEAF_H */ 241