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/* B-tree mutex nested subclasses */
  17enum hfs_btree_mutex_classes {
  18        CATALOG_BTREE_MUTEX,
  19        EXTENTS_BTREE_MUTEX,
  20        ATTR_BTREE_MUTEX,
  21};
  22
  23/* A HFS BTree held in memory */
  24struct hfs_btree {
  25        struct super_block *sb;
  26        struct inode *inode;
  27        btree_keycmp keycmp;
  28
  29        u32 cnid;
  30        u32 root;
  31        u32 leaf_count;
  32        u32 leaf_head;
  33        u32 leaf_tail;
  34        u32 node_count;
  35        u32 free_nodes;
  36        u32 attributes;
  37
  38        unsigned int node_size;
  39        unsigned int node_size_shift;
  40        unsigned int max_key_len;
  41        unsigned int depth;
  42
  43        //unsigned int map1_size, map_size;
  44        struct mutex tree_lock;
  45
  46        unsigned int pages_per_bnode;
  47        spinlock_t hash_lock;
  48        struct hfs_bnode *node_hash[NODE_HASH_SIZE];
  49        int node_hash_cnt;
  50};
  51
  52/* A HFS BTree node in memory */
  53struct hfs_bnode {
  54        struct hfs_btree *tree;
  55
  56        u32 prev;
  57        u32 this;
  58        u32 next;
  59        u32 parent;
  60
  61        u16 num_recs;
  62        u8 type;
  63        u8 height;
  64
  65        struct hfs_bnode *next_hash;
  66        unsigned long flags;
  67        wait_queue_head_t lock_wq;
  68        atomic_t refcnt;
  69        unsigned int page_offset;
  70        struct page *page[];
  71};
  72
  73#define HFS_BNODE_ERROR         0
  74#define HFS_BNODE_NEW           1
  75#define HFS_BNODE_DELETED       2
  76
  77struct hfs_find_data {
  78        btree_key *key;
  79        btree_key *search_key;
  80        struct hfs_btree *tree;
  81        struct hfs_bnode *bnode;
  82        int record;
  83        int keyoffset, keylength;
  84        int entryoffset, entrylength;
  85};
  86
  87
  88/* btree.c */
  89extern struct hfs_btree *hfs_btree_open(struct super_block *, u32, btree_keycmp);
  90extern void hfs_btree_close(struct hfs_btree *);
  91extern void hfs_btree_write(struct hfs_btree *);
  92extern int hfs_bmap_reserve(struct hfs_btree *, int);
  93extern struct hfs_bnode * hfs_bmap_alloc(struct hfs_btree *);
  94extern void hfs_bmap_free(struct hfs_bnode *node);
  95
  96/* bnode.c */
  97extern void hfs_bnode_read(struct hfs_bnode *, void *, int, int);
  98extern u16 hfs_bnode_read_u16(struct hfs_bnode *, int);
  99extern u8 hfs_bnode_read_u8(struct hfs_bnode *, int);
 100extern void hfs_bnode_read_key(struct hfs_bnode *, void *, int);
 101extern void hfs_bnode_write(struct hfs_bnode *, void *, int, int);
 102extern void hfs_bnode_write_u16(struct hfs_bnode *, int, u16);
 103extern void hfs_bnode_write_u8(struct hfs_bnode *, int, u8);
 104extern void hfs_bnode_clear(struct hfs_bnode *, int, int);
 105extern void hfs_bnode_copy(struct hfs_bnode *, int,
 106                           struct hfs_bnode *, int, int);
 107extern void hfs_bnode_move(struct hfs_bnode *, int, int, int);
 108extern void hfs_bnode_dump(struct hfs_bnode *);
 109extern void hfs_bnode_unlink(struct hfs_bnode *);
 110extern struct hfs_bnode *hfs_bnode_findhash(struct hfs_btree *, u32);
 111extern struct hfs_bnode *hfs_bnode_find(struct hfs_btree *, u32);
 112extern void hfs_bnode_unhash(struct hfs_bnode *);
 113extern void hfs_bnode_free(struct hfs_bnode *);
 114extern struct hfs_bnode *hfs_bnode_create(struct hfs_btree *, u32);
 115extern void hfs_bnode_get(struct hfs_bnode *);
 116extern void hfs_bnode_put(struct hfs_bnode *);
 117
 118/* brec.c */
 119extern u16 hfs_brec_lenoff(struct hfs_bnode *, u16, u16 *);
 120extern u16 hfs_brec_keylen(struct hfs_bnode *, u16);
 121extern int hfs_brec_insert(struct hfs_find_data *, void *, int);
 122extern int hfs_brec_remove(struct hfs_find_data *);
 123
 124/* bfind.c */
 125extern int hfs_find_init(struct hfs_btree *, struct hfs_find_data *);
 126extern void hfs_find_exit(struct hfs_find_data *);
 127extern int __hfs_brec_find(struct hfs_bnode *, struct hfs_find_data *);
 128extern int hfs_brec_find(struct hfs_find_data *);
 129extern int hfs_brec_read(struct hfs_find_data *, void *, int);
 130extern int hfs_brec_goto(struct hfs_find_data *, int);
 131
 132
 133struct hfs_bnode_desc {
 134        __be32 next;            /* (V) Number of the next node at this level */
 135        __be32 prev;            /* (V) Number of the prev node at this level */
 136        u8 type;                /* (F) The type of node */
 137        u8 height;              /* (F) The level of this node (leaves=1) */
 138        __be16 num_recs;        /* (V) The number of records in this node */
 139        u16 reserved;
 140} __packed;
 141
 142#define HFS_NODE_INDEX  0x00    /* An internal (index) node */
 143#define HFS_NODE_HEADER 0x01    /* The tree header node (node 0) */
 144#define HFS_NODE_MAP    0x02    /* Holds part of the bitmap of used nodes */
 145#define HFS_NODE_LEAF   0xFF    /* A leaf (ndNHeight==1) node */
 146
 147struct hfs_btree_header_rec {
 148        __be16 depth;           /* (V) The number of levels in this B-tree */
 149        __be32 root;            /* (V) The node number of the root node */
 150        __be32 leaf_count;      /* (V) The number of leaf records */
 151        __be32 leaf_head;       /* (V) The number of the first leaf node */
 152        __be32 leaf_tail;       /* (V) The number of the last leaf node */
 153        __be16 node_size;       /* (F) The number of bytes in a node (=512) */
 154        __be16 max_key_len;     /* (F) The length of a key in an index node */
 155        __be32 node_count;      /* (V) The total number of nodes */
 156        __be32 free_nodes;      /* (V) The number of unused nodes */
 157        u16 reserved1;
 158        __be32 clump_size;      /* (F) clump size. not usually used. */
 159        u8 btree_type;          /* (F) BTree type */
 160        u8 reserved2;
 161        __be32 attributes;      /* (F) attributes */
 162        u32 reserved3[16];
 163} __packed;
 164
 165#define BTREE_ATTR_BADCLOSE     0x00000001      /* b-tree not closed properly. not
 166                                                   used by hfsplus. */
 167#define HFS_TREE_BIGKEYS        0x00000002      /* key length is u16 instead of u8.
 168                                                   used by hfsplus. */
 169#define HFS_TREE_VARIDXKEYS     0x00000004      /* variable key length instead of
 170                                                   max key length. use din catalog
 171                                                   b-tree but not in extents
 172                                                   b-tree (hfsplus). */
 173