--- /dev/null
+/*
+ * 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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
+ */
+
+#ifndef _SYS_ZAP_LEAF_H
+#define _SYS_ZAP_LEAF_H
+
+#include <sys/zap.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct zap;
+struct zap_name;
+struct zap_stats;
+
+#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 *) \
+ (zap_leaf_phys(l)->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 {
+ /* Public to ZAP */
+ 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 */
+
+ /* Private to zap_leaf */
+ 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_value_intlen; /* size of value's ints */
+ uint16_t le_next; /* next entry in hash chain */
+ uint16_t le_name_chunk; /* first chunk of the name */
+ uint16_t le_name_numints; /* ints in name (incl null) */
+ uint16_t le_value_chunk; /* first chunk of the value */
+ uint16_t le_value_numints; /* 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 {
+ dmu_buf_user_t l_dbu;
+ 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_t;
+
+static inline zap_leaf_phys_t *
+zap_leaf_phys(zap_leaf_t *l)
+{
+ return (l->l_dbuf->db_data);
+}
+
+typedef struct zap_entry_handle {
+ /* Set by zap_leaf and public to ZAP */
+ uint64_t zeh_num_integers;
+ uint64_t zeh_hash;
+ uint32_t zeh_cd;
+ uint8_t zeh_integer_size;
+
+ /* Private to zap_leaf */
+ 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,
+ struct zap_name *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(struct zap *zap, const zap_entry_handle_t *zeh,
+ uint16_t buflen, char *buf);
+
+/*
+ * Replace the value of an existing entry.
+ *
+ * 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, struct zap_name *zn, uint32_t cd,
+ uint8_t integer_size, uint64_t num_integers, const void *buf,
+ zap_entry_handle_t *zeh);
+
+/* Determine whether there is another entry with the same normalized form. */
+extern boolean_t zap_entry_normalization_conflict(zap_entry_handle_t *zeh,
+ struct zap_name *zn, const char *name, struct zap *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(struct zap *zap, zap_leaf_t *l,
+ struct zap_stats *zs);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _SYS_ZAP_LEAF_H */
projects / mirror_ubuntu-artful-kernel.git / blobdiff