LXR linux/fs/hfs/btree.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2/*
   3 *  linux/fs/hfs/btree.h
   4 *
   5 * Copyright (C) 2001
   6 * Brad Boyer (flar@allandria.com)
   7 * (C) 2003 Ardis Technologies <roman@ardistech.com>
   8 */
   9
  10#include "hfs_fs.h"
  11
  12typedef int (*btree_keycmp)(const btree_key *, const btree_key *);
  13
  14#define NODE_HASH_SIZE  256
  15
  16/* A HFS BTree held in memory */
  17struct hfs_btree {
  18        struct super_block *sb;
  19        struct inode *inode;
  20        btree_keycmp keycmp;
  21
  22        u32 cnid;
  23        u32 root;
  24        u32 leaf_count;
  25        u32 leaf_head;
  26        u32 leaf_tail;
  27        u32 node_count;
  28        u32 free_nodes;
  29        u32 attributes;
  30
  31        unsigned int node_size;
  32        unsigned int node_size_shift;
  33        unsigned int max_key_len;
  34        unsigned int depth;
  35
  36        //unsigned int map1_size, map_size;
  37        struct mutex tree_lock;
  38
  39        unsigned int pages_per_bnode;
  40        spinlock_t hash_lock;
  41        struct hfs_bnode *node_hash[NODE_HASH_SIZE];
  42        int node_hash_cnt;
  43};
  44
  45/* A HFS BTree node in memory */
  46struct hfs_bnode {
  47        struct hfs_btree *tree;
  48
  49        u32 prev;
  50        u32 this;
  51        u32 next;
  52        u32 parent;
  53
  54        u16 num_recs;
  55        u8 type;
  56        u8 height;
  57
  58        struct hfs_bnode *next_hash;
  59        unsigned long flags;
  60        wait_queue_head_t lock_wq;
  61        atomic_t refcnt;
  62        unsigned int page_offset;
  63        struct page *page[0];
  64};
  65
  66#define HFS_BNODE_ERROR         0
  67#define HFS_BNODE_NEW           1
  68#define HFS_BNODE_DELETED       2
  69
  70struct hfs_find_data {
  71        btree_key *key;
  72        btree_key *search_key;
  73        struct hfs_btree *tree;
  74        struct hfs_bnode *bnode;
  75        int record;
  76        int keyoffset, keylength;
  77        int entryoffset, entrylength;
  78};
  79
  80
  81/* btree.c */
  82extern struct hfs_btree *hfs_btree_open(struct super_block *, u32, btree_keycmp);
  83extern void hfs_btree_close(struct hfs_btree *);
  84extern void hfs_btree_write(struct hfs_btree *);
  85extern int hfs_bmap_reserve(struct hfs_btree *, int);
  86extern struct hfs_bnode * hfs_bmap_alloc(struct hfs_btree *);
  87extern void hfs_bmap_free(struct hfs_bnode *node);
  88
  89/* bnode.c */
  90extern void hfs_bnode_read(struct hfs_bnode *, void *, int, int);
  91extern u16 hfs_bnode_read_u16(struct hfs_bnode *, int);
  92extern u8 hfs_bnode_read_u8(struct hfs_bnode *, int);
  93extern void hfs_bnode_read_key(struct hfs_bnode *, void *, int);
  94extern void hfs_bnode_write(struct hfs_bnode *, void *, int, int);
  95extern void hfs_bnode_write_u16(struct hfs_bnode *, int, u16);
  96extern void hfs_bnode_write_u8(struct hfs_bnode *, int, u8);
  97extern void hfs_bnode_clear(struct hfs_bnode *, int, int);
  98extern void hfs_bnode_copy(struct hfs_bnode *, int,
  99                           struct hfs_bnode *, int, int);
 100extern void hfs_bnode_move(struct hfs_bnode *, int, int, int);
 101extern void hfs_bnode_dump(struct hfs_bnode *);
 102extern void hfs_bnode_unlink(struct hfs_bnode *);
 103extern struct hfs_bnode *hfs_bnode_findhash(struct hfs_btree *, u32);
 104extern struct hfs_bnode *hfs_bnode_find(struct hfs_btree *, u32);
 105extern void hfs_bnode_unhash(struct hfs_bnode *);
 106extern void hfs_bnode_free(struct hfs_bnode *);
 107extern struct hfs_bnode *hfs_bnode_create(struct hfs_btree *, u32);
 108extern void hfs_bnode_get(struct hfs_bnode *);
 109extern void hfs_bnode_put(struct hfs_bnode *);
 110
 111/* brec.c */
 112extern u16 hfs_brec_lenoff(struct hfs_bnode *, u16, u16 *);
 113extern u16 hfs_brec_keylen(struct hfs_bnode *, u16);
 114extern int hfs_brec_insert(struct hfs_find_data *, void *, int);
 115extern int hfs_brec_remove(struct hfs_find_data *);
 116
 117/* bfind.c */
 118extern int hfs_find_init(struct hfs_btree *, struct hfs_find_data *);
 119extern void hfs_find_exit(struct hfs_find_data *);
 120extern int __hfs_brec_find(struct hfs_bnode *, struct hfs_find_data *);
 121extern int hfs_brec_find(struct hfs_find_data *);
 122extern int hfs_brec_read(struct hfs_find_data *, void *, int);
 123extern int hfs_brec_goto(struct hfs_find_data *, int);
 124
 125
 126struct hfs_bnode_desc {
 127        __be32 next;            /* (V) Number of the next node at this level */
 128        __be32 prev;            /* (V) Number of the prev node at this level */
 129        u8 type;                /* (F) The type of node */
 130        u8 height;              /* (F) The level of this node (leaves=1) */
 131        __be16 num_recs;        /* (V) The number of records in this node */
 132        u16 reserved;
 133} __packed;
 134
 135#define HFS_NODE_INDEX  0x00    /* An internal (index) node */
 136#define HFS_NODE_HEADER 0x01    /* The tree header node (node 0) */
 137#define HFS_NODE_MAP    0x02    /* Holds part of the bitmap of used nodes */
 138#define HFS_NODE_LEAF   0xFF    /* A leaf (ndNHeight==1) node */
 139
 140struct hfs_btree_header_rec {
 141        __be16 depth;           /* (V) The number of levels in this B-tree */
 142        __be32 root;            /* (V) The node number of the root node */
 143        __be32 leaf_count;      /* (V) The number of leaf records */
 144        __be32 leaf_head;       /* (V) The number of the first leaf node */
 145        __be32 leaf_tail;       /* (V) The number of the last leaf node */
 146        __be16 node_size;       /* (F) The number of bytes in a node (=512) */
 147        __be16 max_key_len;     /* (F) The length of a key in an index node */
 148        __be32 node_count;      /* (V) The total number of nodes */
 149        __be32 free_nodes;      /* (V) The number of unused nodes */
 150        u16 reserved1;
 151        __be32 clump_size;      /* (F) clump size. not usually used. */
 152        u8 btree_type;          /* (F) BTree type */
 153        u8 reserved2;
 154        __be32 attributes;      /* (F) attributes */
 155        u32 reserved3[16];
 156} __packed;
 157
 158#define BTREE_ATTR_BADCLOSE     0x00000001      /* b-tree not closed properly. not
 159                                                   used by hfsplus. */
 160#define HFS_TREE_BIGKEYS        0x00000002      /* key length is u16 instead of u8.
 161                                                   used by hfsplus. */
 162#define HFS_TREE_VARIDXKEYS     0x00000004      /* variable key length instead of
 163                                                   max key length. use din catalog
 164                                                   b-tree but not in extents
 165                                                   b-tree (hfsplus). */
 166