xref: /linux/fs/hfs/btree.h (revision 861e10be08c69808065d755d3e3cab5d520a2d32)
1 /*
2  *  linux/fs/hfs/btree.h
3  *
4  * Copyright (C) 2001
5  * Brad Boyer (flar@allandria.com)
6  * (C) 2003 Ardis Technologies <roman@ardistech.com>
7  */
8 
9 #include "hfs_fs.h"
10 
11 typedef int (*btree_keycmp)(const btree_key *, const btree_key *);
12 
13 #define NODE_HASH_SIZE  256
14 
15 /* A HFS BTree held in memory */
16 struct hfs_btree {
17 	struct super_block *sb;
18 	struct inode *inode;
19 	btree_keycmp keycmp;
20 
21 	u32 cnid;
22 	u32 root;
23 	u32 leaf_count;
24 	u32 leaf_head;
25 	u32 leaf_tail;
26 	u32 node_count;
27 	u32 free_nodes;
28 	u32 attributes;
29 
30 	unsigned int node_size;
31 	unsigned int node_size_shift;
32 	unsigned int max_key_len;
33 	unsigned int depth;
34 
35 	//unsigned int map1_size, map_size;
36 	struct mutex tree_lock;
37 
38 	unsigned int pages_per_bnode;
39 	spinlock_t hash_lock;
40 	struct hfs_bnode *node_hash[NODE_HASH_SIZE];
41 	int node_hash_cnt;
42 };
43 
44 /* A HFS BTree node in memory */
45 struct hfs_bnode {
46 	struct hfs_btree *tree;
47 
48 	u32 prev;
49 	u32 this;
50 	u32 next;
51 	u32 parent;
52 
53 	u16 num_recs;
54 	u8 type;
55 	u8 height;
56 
57 	struct hfs_bnode *next_hash;
58 	unsigned long flags;
59 	wait_queue_head_t lock_wq;
60 	atomic_t refcnt;
61 	unsigned int page_offset;
62 	struct page *page[0];
63 };
64 
65 #define HFS_BNODE_ERROR		0
66 #define HFS_BNODE_NEW		1
67 #define HFS_BNODE_DELETED	2
68 
69 struct hfs_find_data {
70 	btree_key *key;
71 	btree_key *search_key;
72 	struct hfs_btree *tree;
73 	struct hfs_bnode *bnode;
74 	int record;
75 	int keyoffset, keylength;
76 	int entryoffset, entrylength;
77 };
78 
79 
80 /* btree.c */
81 extern struct hfs_btree *hfs_btree_open(struct super_block *, u32, btree_keycmp);
82 extern void hfs_btree_close(struct hfs_btree *);
83 extern void hfs_btree_write(struct hfs_btree *);
84 extern struct hfs_bnode * hfs_bmap_alloc(struct hfs_btree *);
85 extern void hfs_bmap_free(struct hfs_bnode *node);
86 
87 /* bnode.c */
88 extern void hfs_bnode_read(struct hfs_bnode *, void *, int, int);
89 extern u16 hfs_bnode_read_u16(struct hfs_bnode *, int);
90 extern u8 hfs_bnode_read_u8(struct hfs_bnode *, int);
91 extern void hfs_bnode_read_key(struct hfs_bnode *, void *, int);
92 extern void hfs_bnode_write(struct hfs_bnode *, void *, int, int);
93 extern void hfs_bnode_write_u16(struct hfs_bnode *, int, u16);
94 extern void hfs_bnode_write_u8(struct hfs_bnode *, int, u8);
95 extern void hfs_bnode_clear(struct hfs_bnode *, int, int);
96 extern void hfs_bnode_copy(struct hfs_bnode *, int,
97 			   struct hfs_bnode *, int, int);
98 extern void hfs_bnode_move(struct hfs_bnode *, int, int, int);
99 extern void hfs_bnode_dump(struct hfs_bnode *);
100 extern void hfs_bnode_unlink(struct hfs_bnode *);
101 extern struct hfs_bnode *hfs_bnode_findhash(struct hfs_btree *, u32);
102 extern struct hfs_bnode *hfs_bnode_find(struct hfs_btree *, u32);
103 extern void hfs_bnode_unhash(struct hfs_bnode *);
104 extern void hfs_bnode_free(struct hfs_bnode *);
105 extern struct hfs_bnode *hfs_bnode_create(struct hfs_btree *, u32);
106 extern void hfs_bnode_get(struct hfs_bnode *);
107 extern void hfs_bnode_put(struct hfs_bnode *);
108 
109 /* brec.c */
110 extern u16 hfs_brec_lenoff(struct hfs_bnode *, u16, u16 *);
111 extern u16 hfs_brec_keylen(struct hfs_bnode *, u16);
112 extern int hfs_brec_insert(struct hfs_find_data *, void *, int);
113 extern int hfs_brec_remove(struct hfs_find_data *);
114 
115 /* bfind.c */
116 extern int hfs_find_init(struct hfs_btree *, struct hfs_find_data *);
117 extern void hfs_find_exit(struct hfs_find_data *);
118 extern int __hfs_brec_find(struct hfs_bnode *, struct hfs_find_data *);
119 extern int hfs_brec_find(struct hfs_find_data *);
120 extern int hfs_brec_read(struct hfs_find_data *, void *, int);
121 extern int hfs_brec_goto(struct hfs_find_data *, int);
122 
123 
124 struct hfs_bnode_desc {
125 	__be32 next;		/* (V) Number of the next node at this level */
126 	__be32 prev;		/* (V) Number of the prev node at this level */
127 	u8 type;		/* (F) The type of node */
128 	u8 height;		/* (F) The level of this node (leaves=1) */
129 	__be16 num_recs;	/* (V) The number of records in this node */
130 	u16 reserved;
131 } __packed;
132 
133 #define HFS_NODE_INDEX	0x00	/* An internal (index) node */
134 #define HFS_NODE_HEADER	0x01	/* The tree header node (node 0) */
135 #define HFS_NODE_MAP	0x02	/* Holds part of the bitmap of used nodes */
136 #define HFS_NODE_LEAF	0xFF	/* A leaf (ndNHeight==1) node */
137 
138 struct hfs_btree_header_rec {
139 	__be16 depth;		/* (V) The number of levels in this B-tree */
140 	__be32 root;		/* (V) The node number of the root node */
141 	__be32 leaf_count;	/* (V) The number of leaf records */
142 	__be32 leaf_head;	/* (V) The number of the first leaf node */
143 	__be32 leaf_tail;	/* (V) The number of the last leaf node */
144 	__be16 node_size;	/* (F) The number of bytes in a node (=512) */
145 	__be16 max_key_len;	/* (F) The length of a key in an index node */
146 	__be32 node_count;	/* (V) The total number of nodes */
147 	__be32 free_nodes;	/* (V) The number of unused nodes */
148 	u16 reserved1;
149 	__be32 clump_size;	/* (F) clump size. not usually used. */
150 	u8 btree_type;		/* (F) BTree type */
151 	u8 reserved2;
152 	__be32 attributes;	/* (F) attributes */
153 	u32 reserved3[16];
154 } __packed;
155 
156 #define HFS_NODE_INDEX	0x00	/* An internal (index) node */
157 #define HFS_NODE_HEADER	0x01	/* The tree header node (node 0) */
158 #define HFS_NODE_MAP		0x02	/* Holds part of the bitmap of used nodes */
159 #define HFS_NODE_LEAF		0xFF	/* A leaf (ndNHeight==1) node */
160 
161 #define BTREE_ATTR_BADCLOSE	0x00000001	/* b-tree not closed properly. not
162 						   used by hfsplus. */
163 #define HFS_TREE_BIGKEYS	0x00000002	/* key length is u16 instead of u8.
164 						   used by hfsplus. */
165 #define HFS_TREE_VARIDXKEYS	0x00000004	/* variable key length instead of
166 						   max key length. use din catalog
167 						   b-tree but not in extents
168 						   b-tree (hfsplus). */
169