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Diffstat (limited to 'sys/contrib/opensolaris/uts/common/fs/zfs/sys/zap_leaf.h')
| -rw-r--r-- | sys/contrib/opensolaris/uts/common/fs/zfs/sys/zap_leaf.h | 234 |
1 files changed, 234 insertions, 0 deletions
diff --git a/sys/contrib/opensolaris/uts/common/fs/zfs/sys/zap_leaf.h b/sys/contrib/opensolaris/uts/common/fs/zfs/sys/zap_leaf.h new file mode 100644 index 0000000..147fb72 --- /dev/null +++ b/sys/contrib/opensolaris/uts/common/fs/zfs/sys/zap_leaf.h @@ -0,0 +1,234 @@ +/* + * 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 2006 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; + +/* + * 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_pad2[12]; + } 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; /* only used on head of chain */ + 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, + const char *name, uint64_t h, 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); + +/* + * Other stuff. + */ + +extern void zap_leaf_init(zap_leaf_t *l); +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); +extern void zap_leaf_stats(zap_t *zap, zap_leaf_t *l, zap_stats_t *zs); + +#ifdef __cplusplus +} +#endif + +#endif /* _SYS_ZAP_LEAF_H */ |
