btree.h

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/*
 *  linux/fs/hfs/btree.h
 *
 * Copyright (C) 2001
 * Brad Boyer ([email protected])
 * (C) 2003 Ardis Technologies <[email protected]>
 */

#include "hfs_fs.h"

typedef int (*btree_keycmp)(const btree_key *, const btree_key *);

#define NODE_HASH_SIZE  256

/* A HFS BTree held in memory */
struct hfs_btree {
    struct super_block *sb;
    struct inode *inode;
    btree_keycmp keycmp;

    u32 cnid;
    u32 root;
    u32 leaf_count;
    u32 leaf_head;
    u32 leaf_tail;
    u32 node_count;
    u32 free_nodes;
    u32 attributes;

    unsigned int node_size;
    unsigned int node_size_shift;
    unsigned int max_key_len;
    unsigned int depth;

    //unsigned int map1_size, map_size;
    struct mutex tree_lock;

    unsigned int pages_per_bnode;
    spinlock_t hash_lock;
    struct hfs_bnode *node_hash[NODE_HASH_SIZE];
    int node_hash_cnt;
};

/* A HFS BTree node in memory */
struct hfs_bnode {
    struct hfs_btree *tree;

    u32 prev;
    u32 this;
    u32 next;
    u32 parent;

    u16 num_recs;
    u8 type;
    u8 height;

    struct hfs_bnode *next_hash;
    unsigned long flags;
    wait_queue_head_t lock_wq;
    atomic_t refcnt;
    unsigned int page_offset;
    struct page *page[0];
};

#define HFS_BNODE_ERROR     0
#define HFS_BNODE_NEW       1
#define HFS_BNODE_DELETED   2

struct hfs_find_data {
    btree_key *key;
    btree_key *search_key;
    struct hfs_btree *tree;
    struct hfs_bnode *bnode;
    int record;
    int keyoffset, keylength;
    int entryoffset, entrylength;
};


/* btree.c */
extern struct hfs_btree *hfs_btree_open(struct super_block *, u32, btree_keycmp);
extern void hfs_btree_close(struct hfs_btree *);
extern void hfs_btree_write(struct hfs_btree *);
extern struct hfs_bnode * hfs_bmap_alloc(struct hfs_btree *);
extern void hfs_bmap_free(struct hfs_bnode *node);

/* bnode.c */
extern void hfs_bnode_read(struct hfs_bnode *, void *, int, int);
extern u16 hfs_bnode_read_u16(struct hfs_bnode *, int);
extern u8 hfs_bnode_read_u8(struct hfs_bnode *, int);
extern void hfs_bnode_read_key(struct hfs_bnode *, void *, int);
extern void hfs_bnode_write(struct hfs_bnode *, void *, int, int);
extern void hfs_bnode_write_u16(struct hfs_bnode *, int, u16);
extern void hfs_bnode_write_u8(struct hfs_bnode *, int, u8);
extern void hfs_bnode_clear(struct hfs_bnode *, int, int);
extern void hfs_bnode_copy(struct hfs_bnode *, int,
               struct hfs_bnode *, int, int);
extern void hfs_bnode_move(struct hfs_bnode *, int, int, int);
extern void hfs_bnode_dump(struct hfs_bnode *);
extern void hfs_bnode_unlink(struct hfs_bnode *);
extern struct hfs_bnode *hfs_bnode_findhash(struct hfs_btree *, u32);
extern struct hfs_bnode *hfs_bnode_find(struct hfs_btree *, u32);
extern void hfs_bnode_unhash(struct hfs_bnode *);
extern void hfs_bnode_free(struct hfs_bnode *);
extern struct hfs_bnode *hfs_bnode_create(struct hfs_btree *, u32);
extern void hfs_bnode_get(struct hfs_bnode *);
extern void hfs_bnode_put(struct hfs_bnode *);

/* brec.c */
extern u16 hfs_brec_lenoff(struct hfs_bnode *, u16, u16 *);
extern u16 hfs_brec_keylen(struct hfs_bnode *, u16);
extern int hfs_brec_insert(struct hfs_find_data *, void *, int);
extern int hfs_brec_remove(struct hfs_find_data *);

/* bfind.c */
extern int hfs_find_init(struct hfs_btree *, struct hfs_find_data *);
extern void hfs_find_exit(struct hfs_find_data *);
extern int __hfs_brec_find(struct hfs_bnode *, struct hfs_find_data *);
extern int hfs_brec_find(struct hfs_find_data *);
extern int hfs_brec_read(struct hfs_find_data *, void *, int);
extern int hfs_brec_goto(struct hfs_find_data *, int);


struct hfs_bnode_desc {
    __be32 next;        /* (V) Number of the next node at this level */
    __be32 prev;        /* (V) Number of the prev node at this level */
    u8 type;        /* (F) The type of node */
    u8 height;      /* (F) The level of this node (leaves=1) */
    __be16 num_recs;    /* (V) The number of records in this node */
    u16 reserved;
} __packed;

#define HFS_NODE_INDEX  0x00    /* An internal (index) node */
#define HFS_NODE_HEADER 0x01    /* The tree header node (node 0) */
#define HFS_NODE_MAP    0x02    /* Holds part of the bitmap of used nodes */
#define HFS_NODE_LEAF   0xFF    /* A leaf (ndNHeight==1) node */

struct hfs_btree_header_rec {
    __be16 depth;       /* (V) The number of levels in this B-tree */
    __be32 root;        /* (V) The node number of the root node */
    __be32 leaf_count;  /* (V) The number of leaf records */
    __be32 leaf_head;   /* (V) The number of the first leaf node */
    __be32 leaf_tail;   /* (V) The number of the last leaf node */
    __be16 node_size;   /* (F) The number of bytes in a node (=512) */
    __be16 max_key_len; /* (F) The length of a key in an index node */
    __be32 node_count;  /* (V) The total number of nodes */
    __be32 free_nodes;  /* (V) The number of unused nodes */
    u16 reserved1;
    __be32 clump_size;  /* (F) clump size. not usually used. */
    u8 btree_type;      /* (F) BTree type */
    u8 reserved2;
    __be32 attributes;  /* (F) attributes */
    u32 reserved3[16];
} __packed;

#define HFS_NODE_INDEX  0x00    /* An internal (index) node */
#define HFS_NODE_HEADER 0x01    /* The tree header node (node 0) */
#define HFS_NODE_MAP        0x02    /* Holds part of the bitmap of used nodes */
#define HFS_NODE_LEAF       0xFF    /* A leaf (ndNHeight==1) node */

#define BTREE_ATTR_BADCLOSE 0x00000001  /* b-tree not closed properly. not
                           used by hfsplus. */
#define HFS_TREE_BIGKEYS    0x00000002  /* key length is u16 instead of u8.
                           used by hfsplus. */
#define HFS_TREE_VARIDXKEYS 0x00000004  /* variable key length instead of
                           max key length. use din catalog
                           b-tree but not in extents
                           b-tree (hfsplus). */