Root/fs/jfs/jfs_btree.h

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 *
30struct 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 */
111struct 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
118struct 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
144static 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

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