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