LXR uboot/include/zfs/zap

   1/* SPDX-License-Identifier: GPL-2.0+ */
   2/*
   3 *  GRUB  --  GRand Unified Bootloader
   4 *  Copyright (C) 1999,2000,2001,2002,2003,2004  Free Software Foundation, Inc.
   5 */
   6/*
   7 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
   8 * Use is subject to license terms.
   9 */
  10
  11#ifndef _SYS_ZAP_LEAF_H
  12#define _SYS_ZAP_LEAF_H
  13
  14#define ZAP_LEAF_MAGIC 0x2AB1EAF
  15
  16/* chunk size = 24 bytes */
  17#define ZAP_LEAF_CHUNKSIZE 24
  18
  19/*
  20 * The amount of space within the chunk available for the array is:
  21 * chunk size - space for type (1) - space for next pointer (2)
  22 */
  23#define ZAP_LEAF_ARRAY_BYTES (ZAP_LEAF_CHUNKSIZE - 3)
  24
  25typedef enum zap_chunk_type {
  26        ZAP_CHUNK_FREE = 253,
  27        ZAP_CHUNK_ENTRY = 252,
  28        ZAP_CHUNK_ARRAY = 251,
  29        ZAP_CHUNK_TYPE_MAX = 250
  30} zap_chunk_type_t;
  31
  32/*
  33 * TAKE NOTE:
  34 * If zap_leaf_phys_t is modified, zap_leaf_byteswap() must be modified.
  35 */
  36typedef struct zap_leaf_phys {
  37        struct zap_leaf_header {
  38                uint64_t lh_block_type;         /* ZBT_LEAF */
  39                uint64_t lh_pad1;
  40                uint64_t lh_prefix;             /* hash prefix of this leaf */
  41                uint32_t lh_magic;              /* ZAP_LEAF_MAGIC */
  42                uint16_t lh_nfree;              /* number free chunks */
  43                uint16_t lh_nentries;           /* number of entries */
  44                uint16_t lh_prefix_len;         /* num bits used to id this */
  45
  46                /* above is accessable to zap, below is zap_leaf private */
  47
  48                uint16_t lh_freelist;           /* chunk head of free list */
  49                uint8_t lh_pad2[12];
  50        } l_hdr; /* 2 24-byte chunks */
  51
  52        /*
  53         * The header is followed by a hash table with
  54         * ZAP_LEAF_HASH_NUMENTRIES(zap) entries.  The hash table is
  55         * followed by an array of ZAP_LEAF_NUMCHUNKS(zap)
  56         * zap_leaf_chunk structures.  These structures are accessed
  57         * with the ZAP_LEAF_CHUNK() macro.
  58         */
  59
  60        uint16_t l_hash[1];
  61} zap_leaf_phys_t;
  62
  63typedef union zap_leaf_chunk {
  64        struct zap_leaf_entry {
  65                uint8_t le_type;                /* always ZAP_CHUNK_ENTRY */
  66                uint8_t le_int_size;            /* size of ints */
  67                uint16_t le_next;               /* next entry in hash chain */
  68                uint16_t le_name_chunk;         /* first chunk of the name */
  69                uint16_t le_name_length;        /* bytes in name, incl null */
  70                uint16_t le_value_chunk;        /* first chunk of the value */
  71                uint16_t le_value_length;       /* value length in ints */
  72                uint32_t le_cd;         /* collision differentiator */
  73                uint64_t le_hash;               /* hash value of the name */
  74        } l_entry;
  75        struct zap_leaf_array {
  76                uint8_t la_type;                /* always ZAP_CHUNK_ARRAY */
  77                union {
  78                        uint8_t la_array[ZAP_LEAF_ARRAY_BYTES];
  79                        uint64_t la_array64;
  80                } __attribute__ ((packed));
  81                uint16_t la_next;               /* next blk or CHAIN_END */
  82        } l_array;
  83        struct zap_leaf_free {
  84                uint8_t lf_type;                /* always ZAP_CHUNK_FREE */
  85                uint8_t lf_pad[ZAP_LEAF_ARRAY_BYTES];
  86                uint16_t lf_next;       /* next in free list, or CHAIN_END */
  87        } l_free;
  88} zap_leaf_chunk_t;
  89
  90#endif /* _SYS_ZAP_LEAF_H */
  91