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 https://opensource.org/licenses/CDDL-1.0. 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_BS(bs) \ 50 (((1U << (bs)) - 2 * ZAP_LEAF_HASH_NUMENTRIES_BS(bs)) / \ 51 ZAP_LEAF_CHUNKSIZE - 2) 52 53#define ZAP_LEAF_NUMCHUNKS(l) (ZAP_LEAF_NUMCHUNKS_BS(((l)->l_bs))) 54 55#define ZAP_LEAF_NUMCHUNKS_DEF \ 56 (ZAP_LEAF_NUMCHUNKS_BS(fzap_default_block_shift)) 57 58/* 59 * The amount of space within the chunk available for the array is: 60 * chunk size - space for type (1) - space for next pointer (2) 61 */ 62#define ZAP_LEAF_ARRAY_BYTES (ZAP_LEAF_CHUNKSIZE - 3) 63 64#define ZAP_LEAF_ARRAY_NCHUNKS(bytes) \ 65 (((bytes)+ZAP_LEAF_ARRAY_BYTES-1)/ZAP_LEAF_ARRAY_BYTES) 66 67/* 68 * Low water mark: when there are only this many chunks free, start 69 * growing the ptrtbl. Ideally, this should be larger than a 70 * "reasonably-sized" entry. 20 chunks is more than enough for the 71 * largest directory entry (MAXNAMELEN (256) byte name, 8-byte value), 72 * while still being only around 3% for 16k blocks. 73 */ 74#define ZAP_LEAF_LOW_WATER (20) 75 76/* 77 * The leaf hash table has block size / 2^5 (32) number of entries, 78 * which should be more than enough for the maximum number of entries, 79 * which is less than block size / CHUNKSIZE (24) / minimum number of 80 * chunks per entry (3). 81 */ 82#define ZAP_LEAF_HASH_SHIFT_BS(bs) ((bs) - 5) 83#define ZAP_LEAF_HASH_NUMENTRIES_BS(bs) (1U << ZAP_LEAF_HASH_SHIFT_BS(bs)) 84#define ZAP_LEAF_HASH_SHIFT(l) (ZAP_LEAF_HASH_SHIFT_BS(((l)->l_bs))) 85#define ZAP_LEAF_HASH_NUMENTRIES(l) (ZAP_LEAF_HASH_NUMENTRIES_BS(((l)->l_bs))) 86 87/* 88 * The chunks start immediately after the hash table. The end of the 89 * hash table is at l_hash + HASH_NUMENTRIES, which we simply cast to a 90 * chunk_t. 91 */ 92#define ZAP_LEAF_CHUNK(l, idx) \ 93 ((zap_leaf_chunk_t *) \ 94 (zap_leaf_phys(l)->l_hash + ZAP_LEAF_HASH_NUMENTRIES(l)))[idx] 95#define ZAP_LEAF_ENTRY(l, idx) (&ZAP_LEAF_CHUNK(l, idx).l_entry) 96 97typedef enum zap_chunk_type { 98 ZAP_CHUNK_FREE = 253, 99 ZAP_CHUNK_ENTRY = 252, 100 ZAP_CHUNK_ARRAY = 251, 101 ZAP_CHUNK_TYPE_MAX = 250 102} zap_chunk_type_t; 103 104#define ZLF_ENTRIES_CDSORTED (1<<0) 105 106/* 107 * TAKE NOTE: 108 * If zap_leaf_phys_t is modified, zap_leaf_byteswap() must be modified. 109 */ 110typedef struct zap_leaf_phys { 111 struct zap_leaf_header { 112 /* Public to ZAP */ 113 uint64_t lh_block_type; /* ZBT_LEAF */ 114 uint64_t lh_pad1; 115 uint64_t lh_prefix; /* hash prefix of this leaf */ 116 uint32_t lh_magic; /* ZAP_LEAF_MAGIC */ 117 uint16_t lh_nfree; /* number free chunks */ 118 uint16_t lh_nentries; /* number of entries */ 119 uint16_t lh_prefix_len; /* num bits used to id this */ 120 121 /* Private to zap_leaf */ 122 uint16_t lh_freelist; /* chunk head of free list */ 123 uint8_t lh_flags; /* ZLF_* flags */ 124 uint8_t lh_pad2[11]; 125 } l_hdr; /* 2 24-byte chunks */ 126 127 /* 128 * The header is followed by a hash table with 129 * ZAP_LEAF_HASH_NUMENTRIES(zap) entries. The hash table is 130 * followed by an array of ZAP_LEAF_NUMCHUNKS(zap) 131 * zap_leaf_chunk structures. These structures are accessed 132 * with the ZAP_LEAF_CHUNK() macro. 133 */ 134 135 uint16_t l_hash[]; 136} zap_leaf_phys_t; 137 138typedef union zap_leaf_chunk { 139 struct zap_leaf_entry { 140 uint8_t le_type; /* always ZAP_CHUNK_ENTRY */ 141 uint8_t le_value_intlen; /* size of value's ints */ 142 uint16_t le_next; /* next entry in hash chain */ 143 uint16_t le_name_chunk; /* first chunk of the name */ 144 uint16_t le_name_numints; /* ints in name (incl null) */ 145 uint16_t le_value_chunk; /* first chunk of the value */ 146 uint16_t le_value_numints; /* value length in ints */ 147 uint32_t le_cd; /* collision differentiator */ 148 uint64_t le_hash; /* hash value of the name */ 149 } l_entry; 150 struct zap_leaf_array { 151 uint8_t la_type; /* always ZAP_CHUNK_ARRAY */ 152 uint8_t la_array[ZAP_LEAF_ARRAY_BYTES]; 153 uint16_t la_next; /* next blk or CHAIN_END */ 154 } l_array; 155 struct zap_leaf_free { 156 uint8_t lf_type; /* always ZAP_CHUNK_FREE */ 157 uint8_t lf_pad[ZAP_LEAF_ARRAY_BYTES]; 158 uint16_t lf_next; /* next in free list, or CHAIN_END */ 159 } l_free; 160} zap_leaf_chunk_t; 161 162typedef struct zap_leaf { 163 dmu_buf_user_t l_dbu; 164 krwlock_t l_rwlock; 165 uint64_t l_blkid; /* 1<<ZAP_BLOCK_SHIFT byte block off */ 166 uint_t l_bs; /* block size shift */ 167 dmu_buf_t *l_dbuf; 168} zap_leaf_t; 169 170static inline zap_leaf_phys_t * 171zap_leaf_phys(zap_leaf_t *l) 172{ 173 return (l->l_dbuf->db_data); 174} 175 176typedef struct zap_entry_handle { 177 /* Set by zap_leaf and public to ZAP */ 178 uint64_t zeh_num_integers; 179 uint64_t zeh_hash; 180 uint32_t zeh_cd; 181 uint8_t zeh_integer_size; 182 183 /* Private to zap_leaf */ 184 uint16_t zeh_fakechunk; 185 uint16_t *zeh_chunkp; 186 zap_leaf_t *zeh_leaf; 187} zap_entry_handle_t; 188 189/* 190 * Return a handle to the named entry, or ENOENT if not found. The hash 191 * value must equal zap_hash(name). 192 */ 193extern int zap_leaf_lookup(zap_leaf_t *l, 194 struct zap_name *zn, zap_entry_handle_t *zeh); 195 196/* 197 * Return a handle to the entry with this hash+cd, or the entry with the 198 * next closest hash+cd. 199 */ 200extern int zap_leaf_lookup_closest(zap_leaf_t *l, 201 uint64_t hash, uint32_t cd, zap_entry_handle_t *zeh); 202 203/* 204 * Read the first num_integers in the attribute. Integer size 205 * conversion will be done without sign extension. Return EINVAL if 206 * integer_size is too small. Return EOVERFLOW if there are more than 207 * num_integers in the attribute. 208 */ 209extern int zap_entry_read(const zap_entry_handle_t *zeh, 210 uint8_t integer_size, uint64_t num_integers, void *buf); 211 212extern int zap_entry_read_name(struct zap *zap, const zap_entry_handle_t *zeh, 213 uint16_t buflen, char *buf); 214 215/* 216 * Replace the value of an existing entry. 217 * 218 * May fail if it runs out of space (ENOSPC). 219 */ 220extern int zap_entry_update(zap_entry_handle_t *zeh, 221 uint8_t integer_size, uint64_t num_integers, const void *buf); 222 223/* 224 * Remove an entry. 225 */ 226extern void zap_entry_remove(zap_entry_handle_t *zeh); 227 228/* 229 * Create an entry. An equal entry must not exist, and this entry must 230 * belong in this leaf (according to its hash value). Fills in the 231 * entry handle on success. Returns 0 on success or ENOSPC on failure. 232 */ 233extern int zap_entry_create(zap_leaf_t *l, struct zap_name *zn, uint32_t cd, 234 uint8_t integer_size, uint64_t num_integers, const void *buf, 235 zap_entry_handle_t *zeh); 236 237/* Determine whether there is another entry with the same normalized form. */ 238extern boolean_t zap_entry_normalization_conflict(zap_entry_handle_t *zeh, 239 struct zap_name *zn, const char *name, struct zap *zap); 240 241/* 242 * Other stuff. 243 */ 244 245extern void zap_leaf_init(zap_leaf_t *l, boolean_t sort); 246extern void zap_leaf_byteswap(zap_leaf_phys_t *buf, size_t len); 247extern void zap_leaf_split(zap_leaf_t *l, zap_leaf_t *nl, boolean_t sort); 248extern void zap_leaf_stats(struct zap *zap, zap_leaf_t *l, 249 struct zap_stats *zs); 250 251#ifdef __cplusplus 252} 253#endif 254 255#endif /* _SYS_ZAP_LEAF_H */ 256