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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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
+ */
+
+#ifndef _SYS_ZAP_H
+#define _SYS_ZAP_H
+
+/*
+ * ZAP - ZFS Attribute Processor
+ *
+ * The ZAP is a module which sits on top of the DMU (Data Management
+ * Unit) and implements a higher-level storage primitive using DMU
+ * objects. Its primary consumer is the ZPL (ZFS Posix Layer).
+ *
+ * A "zapobj" is a DMU object which the ZAP uses to stores attributes.
+ * Users should use only zap routines to access a zapobj - they should
+ * not access the DMU object directly using DMU routines.
+ *
+ * The attributes stored in a zapobj are name-value pairs. The name is
+ * a zero-terminated string of up to ZAP_MAXNAMELEN bytes (including
+ * terminating NULL). The value is an array of integers, which may be
+ * 1, 2, 4, or 8 bytes long. The total space used by the array (number
+ * of integers * integer length) can be up to ZAP_MAXVALUELEN bytes.
+ * Note that an 8-byte integer value can be used to store the location
+ * (object number) of another dmu object (which may be itself a zapobj).
+ * Note that you can use a zero-length attribute to store a single bit
+ * of information - the attribute is present or not.
+ *
+ * The ZAP routines are thread-safe. However, you must observe the
+ * DMU's restriction that a transaction may not be operated on
+ * concurrently.
+ *
+ * Any of the routines that return an int may return an I/O error (EIO
+ * or ECHECKSUM).
+ *
+ *
+ * Implementation / Performance Notes:
+ *
+ * The ZAP is intended to operate most efficiently on attributes with
+ * short (49 bytes or less) names and single 8-byte values, for which
+ * the microzap will be used. The ZAP should be efficient enough so
+ * that the user does not need to cache these attributes.
+ *
+ * The ZAP's locking scheme makes its routines thread-safe. Operations
+ * on different zapobjs will be processed concurrently. Operations on
+ * the same zapobj which only read data will be processed concurrently.
+ * Operations on the same zapobj which modify data will be processed
+ * concurrently when there are many attributes in the zapobj (because
+ * the ZAP uses per-block locking - more than 128 * (number of cpus)
+ * small attributes will suffice).
+ */
+
+/*
+ * We're using zero-terminated byte strings (ie. ASCII or UTF-8 C
+ * strings) for the names of attributes, rather than a byte string
+ * bounded by an explicit length. If some day we want to support names
+ * in character sets which have embedded zeros (eg. UTF-16, UTF-32),
+ * we'll have to add routines for using length-bounded strings.
+ */
+
+#include <sys/dmu.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * The matchtype specifies which entry will be accessed.
+ * MT_EXACT: only find an exact match (non-normalized)
+ * MT_FIRST: find the "first" normalized (case and Unicode
+ * form) match; the designated "first" match will not change as long
+ * as the set of entries with this normalization doesn't change
+ * MT_BEST: if there is an exact match, find that, otherwise find the
+ * first normalized match
+ */
+typedef enum matchtype
+{
+ MT_EXACT,
+ MT_BEST,
+ MT_FIRST
+} matchtype_t;
+
+typedef enum zap_flags {
+ /* Use 64-bit hash value (serialized cursors will always use 64-bits) */
+ ZAP_FLAG_HASH64 = 1 << 0,
+ /* Key is binary, not string (zap_add_uint64() can be used) */
+ ZAP_FLAG_UINT64_KEY = 1 << 1,
+ /*
+ * First word of key (which must be an array of uint64) is
+ * already randomly distributed.
+ */
+ ZAP_FLAG_PRE_HASHED_KEY = 1 << 2,
+} zap_flags_t;
+
+/*
+ * Create a new zapobj with no attributes and return its object number.
+ * MT_EXACT will cause the zap object to only support MT_EXACT lookups,
+ * otherwise any matchtype can be used for lookups.
+ *
+ * normflags specifies what normalization will be done. values are:
+ * 0: no normalization (legacy on-disk format, supports MT_EXACT matching
+ * only)
+ * U8_TEXTPREP_TOLOWER: case normalization will be performed.
+ * MT_FIRST/MT_BEST matching will find entries that match without
+ * regard to case (eg. looking for "foo" can find an entry "Foo").
+ * Eventually, other flags will permit unicode normalization as well.
+ */
+uint64_t zap_create(objset_t *ds, dmu_object_type_t ot,
+ dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx);
+uint64_t zap_create_norm(objset_t *ds, int normflags, dmu_object_type_t ot,
+ dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx);
+uint64_t zap_create_flags(objset_t *os, int normflags, zap_flags_t flags,
+ dmu_object_type_t ot, int leaf_blockshift, int indirect_blockshift,
+ dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx);
+
+/*
+ * Create a new zapobj with no attributes from the given (unallocated)
+ * object number.
+ */
+int zap_create_claim(objset_t *ds, uint64_t obj, dmu_object_type_t ot,
+ dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx);
+int zap_create_claim_norm(objset_t *ds, uint64_t obj,
+ int normflags, dmu_object_type_t ot,
+ dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx);
+
+/*
+ * The zapobj passed in must be a valid ZAP object for all of the
+ * following routines.
+ */
+
+/*
+ * Destroy this zapobj and all its attributes.
+ *
+ * Frees the object number using dmu_object_free.
+ */
+int zap_destroy(objset_t *ds, uint64_t zapobj, dmu_tx_t *tx);
+
+/*
+ * Manipulate attributes.
+ *
+ * 'integer_size' is in bytes, and must be 1, 2, 4, or 8.
+ */
+
+/*
+ * Retrieve the contents of the attribute with the given name.
+ *
+ * If the requested attribute does not exist, the call will fail and
+ * return ENOENT.
+ *
+ * If 'integer_size' is smaller than the attribute's integer size, the
+ * call will fail and return EINVAL.
+ *
+ * If 'integer_size' is equal to or larger than the attribute's integer
+ * size, the call will succeed and return 0. * When converting to a
+ * larger integer size, the integers will be treated as unsigned (ie. no
+ * sign-extension will be performed).
+ *
+ * 'num_integers' is the length (in integers) of 'buf'.
+ *
+ * If the attribute is longer than the buffer, as many integers as will
+ * fit will be transferred to 'buf'. If the entire attribute was not
+ * transferred, the call will return EOVERFLOW.
+ *
+ * If rn_len is nonzero, realname will be set to the name of the found
+ * entry (which may be different from the requested name if matchtype is
+ * not MT_EXACT).
+ *
+ * If normalization_conflictp is not NULL, it will be set if there is
+ * another name with the same case/unicode normalized form.
+ */
+int zap_lookup(objset_t *ds, uint64_t zapobj, const char *name,
+ uint64_t integer_size, uint64_t num_integers, void *buf);
+int zap_lookup_norm(objset_t *ds, uint64_t zapobj, const char *name,
+ uint64_t integer_size, uint64_t num_integers, void *buf,
+ matchtype_t mt, char *realname, int rn_len,
+ boolean_t *normalization_conflictp);
+int zap_lookup_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key,
+ int key_numints, uint64_t integer_size, uint64_t num_integers, void *buf);
+int zap_contains(objset_t *ds, uint64_t zapobj, const char *name);
+int zap_prefetch_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key,
+ int key_numints);
+
+int zap_count_write(objset_t *os, uint64_t zapobj, const char *name,
+ int add, uint64_t *towrite, uint64_t *tooverwrite);
+
+/*
+ * Create an attribute with the given name and value.
+ *
+ * If an attribute with the given name already exists, the call will
+ * fail and return EEXIST.
+ */
+int zap_add(objset_t *ds, uint64_t zapobj, const char *key,
+ int integer_size, uint64_t num_integers,
+ const void *val, dmu_tx_t *tx);
+int zap_add_uint64(objset_t *ds, uint64_t zapobj, const uint64_t *key,
+ int key_numints, int integer_size, uint64_t num_integers,
+ const void *val, dmu_tx_t *tx);
+
+/*
+ * Set the attribute with the given name to the given value. If an
+ * attribute with the given name does not exist, it will be created. If
+ * an attribute with the given name already exists, the previous value
+ * will be overwritten. The integer_size may be different from the
+ * existing attribute's integer size, in which case the attribute's
+ * integer size will be updated to the new value.
+ */
+int zap_update(objset_t *ds, uint64_t zapobj, const char *name,
+ int integer_size, uint64_t num_integers, const void *val, dmu_tx_t *tx);
+int zap_update_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key,
+ int key_numints,
+ int integer_size, uint64_t num_integers, const void *val, dmu_tx_t *tx);
+
+/*
+ * Get the length (in integers) and the integer size of the specified
+ * attribute.
+ *
+ * If the requested attribute does not exist, the call will fail and
+ * return ENOENT.
+ */
+int zap_length(objset_t *ds, uint64_t zapobj, const char *name,
+ uint64_t *integer_size, uint64_t *num_integers);
+int zap_length_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key,
+ int key_numints, uint64_t *integer_size, uint64_t *num_integers);
+
+/*
+ * Remove the specified attribute.
+ *
+ * If the specified attribute does not exist, the call will fail and
+ * return ENOENT.
+ */
+int zap_remove(objset_t *ds, uint64_t zapobj, const char *name, dmu_tx_t *tx);
+int zap_remove_norm(objset_t *ds, uint64_t zapobj, const char *name,
+ matchtype_t mt, dmu_tx_t *tx);
+int zap_remove_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key,
+ int key_numints, dmu_tx_t *tx);
+
+/*
+ * Returns (in *count) the number of attributes in the specified zap
+ * object.
+ */
+int zap_count(objset_t *ds, uint64_t zapobj, uint64_t *count);
+
+/*
+ * Returns (in name) the name of the entry whose (value & mask)
+ * (za_first_integer) is value, or ENOENT if not found. The string
+ * pointed to by name must be at least 256 bytes long. If mask==0, the
+ * match must be exact (ie, same as mask=-1ULL).
+ */
+int zap_value_search(objset_t *os, uint64_t zapobj,
+ uint64_t value, uint64_t mask, char *name);
+
+/*
+ * Transfer all the entries from fromobj into intoobj. Only works on
+ * int_size=8 num_integers=1 values. Fails if there are any duplicated
+ * entries.
+ */
+int zap_join(objset_t *os, uint64_t fromobj, uint64_t intoobj, dmu_tx_t *tx);
+
+/* Same as zap_join, but set the values to 'value'. */
+int zap_join_key(objset_t *os, uint64_t fromobj, uint64_t intoobj,
+ uint64_t value, dmu_tx_t *tx);
+
+/* Same as zap_join, but add together any duplicated entries. */
+int zap_join_increment(objset_t *os, uint64_t fromobj, uint64_t intoobj,
+ dmu_tx_t *tx);
+
+/*
+ * Manipulate entries where the name + value are the "same" (the name is
+ * a stringified version of the value).
+ */
+int zap_add_int(objset_t *os, uint64_t obj, uint64_t value, dmu_tx_t *tx);
+int zap_remove_int(objset_t *os, uint64_t obj, uint64_t value, dmu_tx_t *tx);
+int zap_lookup_int(objset_t *os, uint64_t obj, uint64_t value);
+int zap_increment_int(objset_t *os, uint64_t obj, uint64_t key, int64_t delta,
+ dmu_tx_t *tx);
+
+/* Here the key is an int and the value is a different int. */
+int zap_add_int_key(objset_t *os, uint64_t obj,
+ uint64_t key, uint64_t value, dmu_tx_t *tx);
+int zap_lookup_int_key(objset_t *os, uint64_t obj,
+ uint64_t key, uint64_t *valuep);
+
+/*
+ * They name is a stringified version of key; increment its value by
+ * delta. Zero values will be zap_remove()-ed.
+ */
+int zap_increment_int(objset_t *os, uint64_t obj, uint64_t key, int64_t delta,
+ dmu_tx_t *tx);
+int zap_increment(objset_t *os, uint64_t obj, const char *name, int64_t delta,
+ dmu_tx_t *tx);
+
+struct zap;
+struct zap_leaf;
+typedef struct zap_cursor {
+ /* This structure is opaque! */
+ objset_t *zc_objset;
+ struct zap *zc_zap;
+ struct zap_leaf *zc_leaf;
+ uint64_t zc_zapobj;
+ uint64_t zc_serialized;
+ uint64_t zc_hash;
+ uint32_t zc_cd;
+} zap_cursor_t;
+
+typedef struct {
+ int za_integer_length;
+ /*
+ * za_normalization_conflict will be set if there are additional
+ * entries with this normalized form (eg, "foo" and "Foo").
+ */
+ boolean_t za_normalization_conflict;
+ uint64_t za_num_integers;
+ uint64_t za_first_integer; /* no sign extension for <8byte ints */
+ char za_name[MAXNAMELEN];
+} zap_attribute_t;
+
+/*
+ * The interface for listing all the attributes of a zapobj can be
+ * thought of as cursor moving down a list of the attributes one by
+ * one. The cookie returned by the zap_cursor_serialize routine is
+ * persistent across system calls (and across reboot, even).
+ */
+
+/*
+ * Initialize a zap cursor, pointing to the "first" attribute of the
+ * zapobj. You must _fini the cursor when you are done with it.
+ */
+void zap_cursor_init(zap_cursor_t *zc, objset_t *ds, uint64_t zapobj);
+void zap_cursor_fini(zap_cursor_t *zc);
+
+/*
+ * Get the attribute currently pointed to by the cursor. Returns
+ * ENOENT if at the end of the attributes.
+ */
+int zap_cursor_retrieve(zap_cursor_t *zc, zap_attribute_t *za);
+
+/*
+ * Advance the cursor to the next attribute.
+ */
+void zap_cursor_advance(zap_cursor_t *zc);
+
+/*
+ * Get a persistent cookie pointing to the current position of the zap
+ * cursor. The low 4 bits in the cookie are always zero, and thus can
+ * be used as to differentiate a serialized cookie from a different type
+ * of value. The cookie will be less than 2^32 as long as there are
+ * fewer than 2^22 (4.2 million) entries in the zap object.
+ */
+uint64_t zap_cursor_serialize(zap_cursor_t *zc);
+
+/*
+ * Advance the cursor to the attribute having the given key.
+ */
+int zap_cursor_move_to_key(zap_cursor_t *zc, const char *name, matchtype_t mt);
+
+/*
+ * Initialize a zap cursor pointing to the position recorded by
+ * zap_cursor_serialize (in the "serialized" argument). You can also
+ * use a "serialized" argument of 0 to start at the beginning of the
+ * zapobj (ie. zap_cursor_init_serialized(..., 0) is equivalent to
+ * zap_cursor_init(...).)
+ */
+void zap_cursor_init_serialized(zap_cursor_t *zc, objset_t *ds,
+ uint64_t zapobj, uint64_t serialized);
+
+
+#define ZAP_HISTOGRAM_SIZE 10
+
+typedef struct zap_stats {
+ /*
+ * Size of the pointer table (in number of entries).
+ * This is always a power of 2, or zero if it's a microzap.
+ * In general, it should be considerably greater than zs_num_leafs.
+ */
+ uint64_t zs_ptrtbl_len;
+
+ uint64_t zs_blocksize; /* size of zap blocks */
+
+ /*
+ * The number of blocks used. Note that some blocks may be
+ * wasted because old ptrtbl's and large name/value blocks are
+ * not reused. (Although their space is reclaimed, we don't
+ * reuse those offsets in the object.)
+ */
+ uint64_t zs_num_blocks;
+
+ /*
+ * Pointer table values from zap_ptrtbl in the zap_phys_t
+ */
+ uint64_t zs_ptrtbl_nextblk; /* next (larger) copy start block */
+ uint64_t zs_ptrtbl_blks_copied; /* number source blocks copied */
+ uint64_t zs_ptrtbl_zt_blk; /* starting block number */
+ uint64_t zs_ptrtbl_zt_numblks; /* number of blocks */
+ uint64_t zs_ptrtbl_zt_shift; /* bits to index it */
+
+ /*
+ * Values of the other members of the zap_phys_t
+ */
+ uint64_t zs_block_type; /* ZBT_HEADER */
+ uint64_t zs_magic; /* ZAP_MAGIC */
+ uint64_t zs_num_leafs; /* The number of leaf blocks */
+ uint64_t zs_num_entries; /* The number of zap entries */
+ uint64_t zs_salt; /* salt to stir into hash function */
+
+ /*
+ * Histograms. For all histograms, the last index
+ * (ZAP_HISTOGRAM_SIZE-1) includes any values which are greater
+ * than what can be represented. For example
+ * zs_leafs_with_n5_entries[ZAP_HISTOGRAM_SIZE-1] is the number
+ * of leafs with more than 45 entries.
+ */
+
+ /*
+ * zs_leafs_with_n_pointers[n] is the number of leafs with
+ * 2^n pointers to it.
+ */
+ uint64_t zs_leafs_with_2n_pointers[ZAP_HISTOGRAM_SIZE];
+
+ /*
+ * zs_leafs_with_n_entries[n] is the number of leafs with
+ * [n*5, (n+1)*5) entries. In the current implementation, there
+ * can be at most 55 entries in any block, but there may be
+ * fewer if the name or value is large, or the block is not
+ * completely full.
+ */
+ uint64_t zs_blocks_with_n5_entries[ZAP_HISTOGRAM_SIZE];
+
+ /*
+ * zs_leafs_n_tenths_full[n] is the number of leafs whose
+ * fullness is in the range [n/10, (n+1)/10).
+ */
+ uint64_t zs_blocks_n_tenths_full[ZAP_HISTOGRAM_SIZE];
+
+ /*
+ * zs_entries_using_n_chunks[n] is the number of entries which
+ * consume n 24-byte chunks. (Note, large names/values only use
+ * one chunk, but contribute to zs_num_blocks_large.)
+ */
+ uint64_t zs_entries_using_n_chunks[ZAP_HISTOGRAM_SIZE];
+
+ /*
+ * zs_buckets_with_n_entries[n] is the number of buckets (each
+ * leaf has 64 buckets) with n entries.
+ * zs_buckets_with_n_entries[1] should be very close to
+ * zs_num_entries.
+ */
+ uint64_t zs_buckets_with_n_entries[ZAP_HISTOGRAM_SIZE];
+} zap_stats_t;
+
+/*
+ * Get statistics about a ZAP object. Note: you need to be aware of the
+ * internal implementation of the ZAP to correctly interpret some of the
+ * statistics. This interface shouldn't be relied on unless you really
+ * know what you're doing.
+ */
+int zap_get_stats(objset_t *ds, uint64_t zapobj, zap_stats_t *zs);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _SYS_ZAP_H */