xref: /openbmc/linux/fs/hfs/btree.h (revision bbecb07f)
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 /* A HFS BTree held in memory */
17 struct 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 */
46 struct 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 
70 struct 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 */
82 extern struct hfs_btree *hfs_btree_open(struct super_block *, u32, btree_keycmp);
83 extern void hfs_btree_close(struct hfs_btree *);
84 extern void hfs_btree_write(struct hfs_btree *);
85 extern struct hfs_bnode * hfs_bmap_alloc(struct hfs_btree *);
86 extern void hfs_bmap_free(struct hfs_bnode *node);
87 
88 /* bnode.c */
89 extern void hfs_bnode_read(struct hfs_bnode *, void *, int, int);
90 extern u16 hfs_bnode_read_u16(struct hfs_bnode *, int);
91 extern u8 hfs_bnode_read_u8(struct hfs_bnode *, int);
92 extern void hfs_bnode_read_key(struct hfs_bnode *, void *, int);
93 extern void hfs_bnode_write(struct hfs_bnode *, void *, int, int);
94 extern void hfs_bnode_write_u16(struct hfs_bnode *, int, u16);
95 extern void hfs_bnode_write_u8(struct hfs_bnode *, int, u8);
96 extern void hfs_bnode_clear(struct hfs_bnode *, int, int);
97 extern void hfs_bnode_copy(struct hfs_bnode *, int,
98 			   struct hfs_bnode *, int, int);
99 extern void hfs_bnode_move(struct hfs_bnode *, int, int, int);
100 extern void hfs_bnode_dump(struct hfs_bnode *);
101 extern void hfs_bnode_unlink(struct hfs_bnode *);
102 extern struct hfs_bnode *hfs_bnode_findhash(struct hfs_btree *, u32);
103 extern struct hfs_bnode *hfs_bnode_find(struct hfs_btree *, u32);
104 extern void hfs_bnode_unhash(struct hfs_bnode *);
105 extern void hfs_bnode_free(struct hfs_bnode *);
106 extern struct hfs_bnode *hfs_bnode_create(struct hfs_btree *, u32);
107 extern void hfs_bnode_get(struct hfs_bnode *);
108 extern void hfs_bnode_put(struct hfs_bnode *);
109 
110 /* brec.c */
111 extern u16 hfs_brec_lenoff(struct hfs_bnode *, u16, u16 *);
112 extern u16 hfs_brec_keylen(struct hfs_bnode *, u16);
113 extern int hfs_brec_insert(struct hfs_find_data *, void *, int);
114 extern int hfs_brec_remove(struct hfs_find_data *);
115 
116 /* bfind.c */
117 extern int hfs_find_init(struct hfs_btree *, struct hfs_find_data *);
118 extern void hfs_find_exit(struct hfs_find_data *);
119 extern int __hfs_brec_find(struct hfs_bnode *, struct hfs_find_data *);
120 extern int hfs_brec_find(struct hfs_find_data *);
121 extern int hfs_brec_read(struct hfs_find_data *, void *, int);
122 extern int hfs_brec_goto(struct hfs_find_data *, int);
123 
124 
125 struct hfs_bnode_desc {
126 	__be32 next;		/* (V) Number of the next node at this level */
127 	__be32 prev;		/* (V) Number of the prev node at this level */
128 	u8 type;		/* (F) The type of node */
129 	u8 height;		/* (F) The level of this node (leaves=1) */
130 	__be16 num_recs;	/* (V) The number of records in this node */
131 	u16 reserved;
132 } __packed;
133 
134 #define HFS_NODE_INDEX	0x00	/* An internal (index) node */
135 #define HFS_NODE_HEADER	0x01	/* The tree header node (node 0) */
136 #define HFS_NODE_MAP	0x02	/* Holds part of the bitmap of used nodes */
137 #define HFS_NODE_LEAF	0xFF	/* A leaf (ndNHeight==1) node */
138 
139 struct hfs_btree_header_rec {
140 	__be16 depth;		/* (V) The number of levels in this B-tree */
141 	__be32 root;		/* (V) The node number of the root node */
142 	__be32 leaf_count;	/* (V) The number of leaf records */
143 	__be32 leaf_head;	/* (V) The number of the first leaf node */
144 	__be32 leaf_tail;	/* (V) The number of the last leaf node */
145 	__be16 node_size;	/* (F) The number of bytes in a node (=512) */
146 	__be16 max_key_len;	/* (F) The length of a key in an index node */
147 	__be32 node_count;	/* (V) The total number of nodes */
148 	__be32 free_nodes;	/* (V) The number of unused nodes */
149 	u16 reserved1;
150 	__be32 clump_size;	/* (F) clump size. not usually used. */
151 	u8 btree_type;		/* (F) BTree type */
152 	u8 reserved2;
153 	__be32 attributes;	/* (F) attributes */
154 	u32 reserved3[16];
155 } __packed;
156 
157 #define BTREE_ATTR_BADCLOSE	0x00000001	/* b-tree not closed properly. not
158 						   used by hfsplus. */
159 #define HFS_TREE_BIGKEYS	0x00000002	/* key length is u16 instead of u8.
160 						   used by hfsplus. */
161 #define HFS_TREE_VARIDXKEYS	0x00000004	/* variable key length instead of
162 						   max key length. use din catalog
163 						   b-tree but not in extents
164 						   b-tree (hfsplus). */
165