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
32 extern "C" {
33 #endif
34
35 struct zap;
36 struct zap_name;
37 struct 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
97 typedef 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 */
110 typedef 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
138 typedef 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
162 typedef 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
170 static inline zap_leaf_phys_t *
zap_leaf_phys(zap_leaf_t * l)171 zap_leaf_phys(zap_leaf_t *l)
172 {
173 return (l->l_dbuf->db_data);
174 }
175
176 typedef 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 */
193 extern 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 */
200 extern 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 */
209 extern int zap_entry_read(const zap_entry_handle_t *zeh,
210 uint8_t integer_size, uint64_t num_integers, void *buf);
211
212 extern 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 */
220 extern 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 */
226 extern 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 */
233 extern 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. */
238 extern 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
245 extern void zap_leaf_init(zap_leaf_t *l, boolean_t sort);
246 extern void zap_leaf_byteswap(zap_leaf_phys_t *buf, size_t len);
247 extern void zap_leaf_split(zap_leaf_t *l, zap_leaf_t *nl, boolean_t sort);
248 extern 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