1 /*
2 * Copyright (C) International Business Machines Corp., 2000-2004
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
12 * the GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 */
18 #ifndef _H_JFS_BTREE
19 #define _H_JFS_BTREE
20
21 /*
22 * jfs_btree.h: B+-tree
23 *
24 * JFS B+-tree (dtree and xtree) common definitions
25 */
26
27 /*
28 * basic btree page - btpage
29 *
30 struct btpage {
31 s64 next; right sibling bn
32 s64 prev; left sibling bn
33
34 u8 flag;
35 u8 rsrvd[7]; type specific
36 s64 self; self address
37
38 u8 entry[4064];
39 }; */
40
41 /* btpaget_t flag */
42 #define BT_TYPE 0x07 /* B+-tree index */
43 #define BT_ROOT 0x01 /* root page */
44 #define BT_LEAF 0x02 /* leaf page */
45 #define BT_INTERNAL 0x04 /* internal page */
46 #define BT_RIGHTMOST 0x10 /* rightmost page */
47 #define BT_LEFTMOST 0x20 /* leftmost page */
48 #define BT_SWAPPED 0x80 /* used by fsck for endian swapping */
49
50 /* btorder (in inode) */
51 #define BT_RANDOM 0x0000
52 #define BT_SEQUENTIAL 0x0001
53 #define BT_LOOKUP 0x0010
54 #define BT_INSERT 0x0020
55 #define BT_DELETE 0x0040
56
57 /*
58 * btree page buffer cache access
59 */
60 #define BT_IS_ROOT(MP) (((MP)->xflag & COMMIT_PAGE) == 0)
61
62 /* get page from buffer page */
63 #define BT_PAGE(IP, MP, TYPE, ROOT)\
64 (BT_IS_ROOT(MP) ? (TYPE *)&JFS_IP(IP)->ROOT : (TYPE *)(MP)->data)
65
66 /* get the page buffer and the page for specified block address */
67 #define BT_GETPAGE(IP, BN, MP, TYPE, SIZE, P, RC, ROOT)\
68 {\
69 if ((BN) == 0)\
70 {\
71 MP = (struct metapage *)&JFS_IP(IP)->bxflag;\
72 P = (TYPE *)&JFS_IP(IP)->ROOT;\
73 RC = 0;\
74 }\
75 else\
76 {\
77 MP = read_metapage((IP), BN, SIZE, 1);\
78 if (MP) {\
79 RC = 0;\
80 P = (MP)->data;\
81 } else {\
82 P = NULL;\
83 jfs_err("bread failed!");\
84 RC = -EIO;\
85 }\
86 }\
87 }
88
89 #define BT_MARK_DIRTY(MP, IP)\
90 {\
91 if (BT_IS_ROOT(MP))\
92 mark_inode_dirty(IP);\
93 else\
94 mark_metapage_dirty(MP);\
95 }
96
97 /* put the page buffer */
98 #define BT_PUTPAGE(MP)\
99 {\
100 if (! BT_IS_ROOT(MP)) \
101 release_metapage(MP); \
102 }
103
104
105 /*
106 * btree traversal stack
107 *
108 * record the path traversed during the search;
109 * top frame record the leaf page/entry selected.
110 */
111 struct btframe { /* stack frame */
112 s64 bn; /* 8: */
113 s16 index; /* 2: */
114 s16 lastindex; /* 2: unused */
115 struct metapage *mp; /* 4/8: */
116 }; /* (16/24) */
117
118 struct btstack {
119 struct btframe *top;
120 int nsplit;
121 struct btframe stack[MAXTREEHEIGHT];
122 };
123
124 #define BT_CLR(btstack)\
125 (btstack)->top = (btstack)->stack
126
127 #define BT_STACK_FULL(btstack)\
128 ( (btstack)->top == &((btstack)->stack[MAXTREEHEIGHT-1]))
129
130 #define BT_PUSH(BTSTACK, BN, INDEX)\
131 {\
132 assert(!BT_STACK_FULL(BTSTACK));\
133 (BTSTACK)->top->bn = BN;\
134 (BTSTACK)->top->index = INDEX;\
135 ++(BTSTACK)->top;\
136 }
137
138 #define BT_POP(btstack)\
139 ( (btstack)->top == (btstack)->stack ? NULL : --(btstack)->top )
140
141 #define BT_STACK(btstack)\
142 ( (btstack)->top == (btstack)->stack ? NULL : (btstack)->top )
143
BT_STACK_DUMP(struct btstack * btstack)144 static inline void BT_STACK_DUMP(struct btstack *btstack)
145 {
146 int i;
147 printk("btstack dump:\n");
148 for (i = 0; i < MAXTREEHEIGHT; i++)
149 printk(KERN_ERR "bn = %Lx, index = %d\n",
150 (long long)btstack->stack[i].bn,
151 btstack->stack[i].index);
152 }
153
154 /* retrieve search results */
155 #define BT_GETSEARCH(IP, LEAF, BN, MP, TYPE, P, INDEX, ROOT)\
156 {\
157 BN = (LEAF)->bn;\
158 MP = (LEAF)->mp;\
159 if (BN)\
160 P = (TYPE *)MP->data;\
161 else\
162 P = (TYPE *)&JFS_IP(IP)->ROOT;\
163 INDEX = (LEAF)->index;\
164 }
165
166 /* put the page buffer of search */
167 #define BT_PUTSEARCH(BTSTACK)\
168 {\
169 if (! BT_IS_ROOT((BTSTACK)->top->mp))\
170 release_metapage((BTSTACK)->top->mp);\
171 }
172 #endif /* _H_JFS_BTREE */
173