xref: /linux/fs/hfs/btree.h (revision 762f99f4f3cb41a775b5157dd761217beba65873)
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 
12 typedef int (*btree_keycmp)(const btree_key *, const btree_key *);
13 
14 #define NODE_HASH_SIZE  256
15 
16 /* B-tree mutex nested subclasses */
17 enum 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 */
24 struct 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 */
53 struct 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 
77 struct 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 */
89 extern struct hfs_btree *hfs_btree_open(struct super_block *, u32, btree_keycmp);
90 extern void hfs_btree_close(struct hfs_btree *);
91 extern void hfs_btree_write(struct hfs_btree *);
92 extern int hfs_bmap_reserve(struct hfs_btree *, int);
93 extern struct hfs_bnode * hfs_bmap_alloc(struct hfs_btree *);
94 extern void hfs_bmap_free(struct hfs_bnode *node);
95 
96 /* bnode.c */
97 extern void hfs_bnode_read(struct hfs_bnode *, void *, int, int);
98 extern u16 hfs_bnode_read_u16(struct hfs_bnode *, int);
99 extern u8 hfs_bnode_read_u8(struct hfs_bnode *, int);
100 extern void hfs_bnode_read_key(struct hfs_bnode *, void *, int);
101 extern void hfs_bnode_write(struct hfs_bnode *, void *, int, int);
102 extern void hfs_bnode_write_u16(struct hfs_bnode *, int, u16);
103 extern void hfs_bnode_write_u8(struct hfs_bnode *, int, u8);
104 extern void hfs_bnode_clear(struct hfs_bnode *, int, int);
105 extern void hfs_bnode_copy(struct hfs_bnode *, int,
106 			   struct hfs_bnode *, int, int);
107 extern void hfs_bnode_move(struct hfs_bnode *, int, int, int);
108 extern void hfs_bnode_dump(struct hfs_bnode *);
109 extern void hfs_bnode_unlink(struct hfs_bnode *);
110 extern struct hfs_bnode *hfs_bnode_findhash(struct hfs_btree *, u32);
111 extern struct hfs_bnode *hfs_bnode_find(struct hfs_btree *, u32);
112 extern void hfs_bnode_unhash(struct hfs_bnode *);
113 extern void hfs_bnode_free(struct hfs_bnode *);
114 extern struct hfs_bnode *hfs_bnode_create(struct hfs_btree *, u32);
115 extern void hfs_bnode_get(struct hfs_bnode *);
116 extern void hfs_bnode_put(struct hfs_bnode *);
117 
118 /* brec.c */
119 extern u16 hfs_brec_lenoff(struct hfs_bnode *, u16, u16 *);
120 extern u16 hfs_brec_keylen(struct hfs_bnode *, u16);
121 extern int hfs_brec_insert(struct hfs_find_data *, void *, int);
122 extern int hfs_brec_remove(struct hfs_find_data *);
123 
124 /* bfind.c */
125 extern int hfs_find_init(struct hfs_btree *, struct hfs_find_data *);
126 extern void hfs_find_exit(struct hfs_find_data *);
127 extern int __hfs_brec_find(struct hfs_bnode *, struct hfs_find_data *);
128 extern int hfs_brec_find(struct hfs_find_data *);
129 extern int hfs_brec_read(struct hfs_find_data *, void *, int);
130 extern int hfs_brec_goto(struct hfs_find_data *, int);
131 
132 
133 struct 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 
147 struct 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