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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2008 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#ifndef _SYS_ZAP_LEAF_H
#define _SYS_ZAP_LEAF_H
#pragma ident "%Z%%M% %I% %E% SMI"
#ifdef __cplusplus
extern "C" {
#endif
struct zap;
#define ZAP_LEAF_MAGIC 0x2AB1EAF
/* chunk size = 24 bytes */
#define ZAP_LEAF_CHUNKSIZE 24
/*
* The amount of space available for chunks is:
* block size (1<<l->l_bs) - hash entry size (2) * number of hash
* entries - header space (2*chunksize)
*/
#define ZAP_LEAF_NUMCHUNKS(l) \
(((1<<(l)->l_bs) - 2*ZAP_LEAF_HASH_NUMENTRIES(l)) / \
ZAP_LEAF_CHUNKSIZE - 2)
/*
* The amount of space within the chunk available for the array is:
* chunk size - space for type (1) - space for next pointer (2)
*/
#define ZAP_LEAF_ARRAY_BYTES (ZAP_LEAF_CHUNKSIZE - 3)
#define ZAP_LEAF_ARRAY_NCHUNKS(bytes) \
(((bytes)+ZAP_LEAF_ARRAY_BYTES-1)/ZAP_LEAF_ARRAY_BYTES)
/*
* Low water mark: when there are only this many chunks free, start
* growing the ptrtbl. Ideally, this should be larger than a
* "reasonably-sized" entry. 20 chunks is more than enough for the
* largest directory entry (MAXNAMELEN (256) byte name, 8-byte value),
* while still being only around 3% for 16k blocks.
*/
#define ZAP_LEAF_LOW_WATER (20)
/*
* The leaf hash table has block size / 2^5 (32) number of entries,
* which should be more than enough for the maximum number of entries,
* which is less than block size / CHUNKSIZE (24) / minimum number of
* chunks per entry (3).
*/
#define ZAP_LEAF_HASH_SHIFT(l) ((l)->l_bs - 5)
#define ZAP_LEAF_HASH_NUMENTRIES(l) (1 << ZAP_LEAF_HASH_SHIFT(l))
/*
* The chunks start immediately after the hash table. The end of the
* hash table is at l_hash + HASH_NUMENTRIES, which we simply cast to a
* chunk_t.
*/
#define ZAP_LEAF_CHUNK(l, idx) \
((zap_leaf_chunk_t *) \
((l)->l_phys->l_hash + ZAP_LEAF_HASH_NUMENTRIES(l)))[idx]
#define ZAP_LEAF_ENTRY(l, idx) (&ZAP_LEAF_CHUNK(l, idx).l_entry)
typedef enum zap_chunk_type {
ZAP_CHUNK_FREE = 253,
ZAP_CHUNK_ENTRY = 252,
ZAP_CHUNK_ARRAY = 251,
ZAP_CHUNK_TYPE_MAX = 250
} zap_chunk_type_t;
#define ZLF_ENTRIES_CDSORTED (1<<0)
/*
* TAKE NOTE:
* If zap_leaf_phys_t is modified, zap_leaf_byteswap() must be modified.
*/
typedef struct zap_leaf_phys {
struct zap_leaf_header {
uint64_t lh_block_type; /* ZBT_LEAF */
uint64_t lh_pad1;
uint64_t lh_prefix; /* hash prefix of this leaf */
uint32_t lh_magic; /* ZAP_LEAF_MAGIC */
uint16_t lh_nfree; /* number free chunks */
uint16_t lh_nentries; /* number of entries */
uint16_t lh_prefix_len; /* num bits used to id this */
/* above is accessable to zap, below is zap_leaf private */
uint16_t lh_freelist; /* chunk head of free list */
uint8_t lh_flags; /* ZLF_* flags */
uint8_t lh_pad2[11];
} l_hdr; /* 2 24-byte chunks */
/*
* The header is followed by a hash table with
* ZAP_LEAF_HASH_NUMENTRIES(zap) entries. The hash table is
* followed by an array of ZAP_LEAF_NUMCHUNKS(zap)
* zap_leaf_chunk structures. These structures are accessed
* with the ZAP_LEAF_CHUNK() macro.
*/
uint16_t l_hash[1];
} zap_leaf_phys_t;
typedef union zap_leaf_chunk {
struct zap_leaf_entry {
uint8_t le_type; /* always ZAP_CHUNK_ENTRY */
uint8_t le_int_size; /* size of ints */
uint16_t le_next; /* next entry in hash chain */
uint16_t le_name_chunk; /* first chunk of the name */
uint16_t le_name_length; /* bytes in name, incl null */
uint16_t le_value_chunk; /* first chunk of the value */
uint16_t le_value_length; /* value length in ints */
uint32_t le_cd; /* collision differentiator */
uint64_t le_hash; /* hash value of the name */
} l_entry;
struct zap_leaf_array {
uint8_t la_type; /* always ZAP_CHUNK_ARRAY */
uint8_t la_array[ZAP_LEAF_ARRAY_BYTES];
uint16_t la_next; /* next blk or CHAIN_END */
} l_array;
struct zap_leaf_free {
uint8_t lf_type; /* always ZAP_CHUNK_FREE */
uint8_t lf_pad[ZAP_LEAF_ARRAY_BYTES];
uint16_t lf_next; /* next in free list, or CHAIN_END */
} l_free;
} zap_leaf_chunk_t;
typedef struct zap_leaf {
krwlock_t l_rwlock;
uint64_t l_blkid; /* 1<<ZAP_BLOCK_SHIFT byte block off */
int l_bs; /* block size shift */
dmu_buf_t *l_dbuf;
zap_leaf_phys_t *l_phys;
} zap_leaf_t;
typedef struct zap_entry_handle {
/* below is set by zap_leaf.c and is public to zap.c */
uint64_t zeh_num_integers;
uint64_t zeh_hash;
uint32_t zeh_cd;
uint8_t zeh_integer_size;
/* below is private to zap_leaf.c */
uint16_t zeh_fakechunk;
uint16_t *zeh_chunkp;
zap_leaf_t *zeh_leaf;
} zap_entry_handle_t;
/*
* Return a handle to the named entry, or ENOENT if not found. The hash
* value must equal zap_hash(name).
*/
extern int zap_leaf_lookup(zap_leaf_t *l,
zap_name_t *zn, zap_entry_handle_t *zeh);
/*
* Return a handle to the entry with this hash+cd, or the entry with the
* next closest hash+cd.
*/
extern int zap_leaf_lookup_closest(zap_leaf_t *l,
uint64_t hash, uint32_t cd, zap_entry_handle_t *zeh);
/*
* Read the first num_integers in the attribute. Integer size
* conversion will be done without sign extension. Return EINVAL if
* integer_size is too small. Return EOVERFLOW if there are more than
* num_integers in the attribute.
*/
extern int zap_entry_read(const zap_entry_handle_t *zeh,
uint8_t integer_size, uint64_t num_integers, void *buf);
extern int zap_entry_read_name(const zap_entry_handle_t *zeh,
uint16_t buflen, char *buf);
/*
* Replace the value of an existing entry.
*
* zap_entry_update may fail if it runs out of space (ENOSPC).
*/
extern int zap_entry_update(zap_entry_handle_t *zeh,
uint8_t integer_size, uint64_t num_integers, const void *buf);
/*
* Remove an entry.
*/
extern void zap_entry_remove(zap_entry_handle_t *zeh);
/*
* Create an entry. An equal entry must not exist, and this entry must
* belong in this leaf (according to its hash value). Fills in the
* entry handle on success. Returns 0 on success or ENOSPC on failure.
*/
extern int zap_entry_create(zap_leaf_t *l,
const char *name, uint64_t h, uint32_t cd,
uint8_t integer_size, uint64_t num_integers, const void *buf,
zap_entry_handle_t *zeh);
/*
* Return true if there are additional entries with the same normalized
* form.
*/
extern boolean_t zap_entry_normalization_conflict(zap_entry_handle_t *zeh,
zap_name_t *zn, const char *name, zap_t *zap);
/*
* Other stuff.
*/
extern void zap_leaf_init(zap_leaf_t *l, boolean_t sort);
extern void zap_leaf_byteswap(zap_leaf_phys_t *buf, int len);
extern void zap_leaf_split(zap_leaf_t *l, zap_leaf_t *nl, boolean_t sort);
extern void zap_leaf_stats(zap_t *zap, zap_leaf_t *l, zap_stats_t *zs);
#ifdef __cplusplus
}
#endif
#endif /* _SYS_ZAP_LEAF_H */
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