1  /* SPDX-License-Identifier: GPL-2.0-or-later */
2  /*
3   *   Copyright (C) International Business Machines Corp., 2000-2004
4   */
5  #ifndef	_H_JFS_BTREE
6  #define _H_JFS_BTREE
7  
8  /*
9   *	jfs_btree.h: B+-tree
10   *
11   * JFS B+-tree (dtree and xtree) common definitions
12   */
13  
14  /*
15   *	basic btree page - btpage
16   *
17  struct btpage {
18  	s64 next;		right sibling bn
19  	s64 prev;		left sibling bn
20  
21  	u8 flag;
22  	u8 rsrvd[7];		type specific
23  	s64 self;		self address
24  
25  	u8 entry[4064];
26  };						*/
27  
28  /* btpaget_t flag */
29  #define BT_TYPE		0x07	/* B+-tree index */
30  #define	BT_ROOT		0x01	/* root page */
31  #define	BT_LEAF		0x02	/* leaf page */
32  #define	BT_INTERNAL	0x04	/* internal page */
33  #define	BT_RIGHTMOST	0x10	/* rightmost page */
34  #define	BT_LEFTMOST	0x20	/* leftmost page */
35  #define	BT_SWAPPED	0x80	/* used by fsck for endian swapping */
36  
37  /* btorder (in inode) */
38  #define	BT_RANDOM		0x0000
39  #define	BT_SEQUENTIAL		0x0001
40  #define	BT_LOOKUP		0x0010
41  #define	BT_INSERT		0x0020
42  #define	BT_DELETE		0x0040
43  
44  /*
45   *	btree page buffer cache access
46   */
47  #define BT_IS_ROOT(MP) (((MP)->xflag & COMMIT_PAGE) == 0)
48  
49  /* get page from buffer page */
50  #define BT_PAGE(IP, MP, TYPE, ROOT)\
51  	(BT_IS_ROOT(MP) ? (TYPE *)&JFS_IP(IP)->ROOT : (TYPE *)(MP)->data)
52  
53  /* get the page buffer and the page for specified block address */
54  #define BT_GETPAGE(IP, BN, MP, TYPE, SIZE, P, RC, ROOT)\
55  {\
56  	if ((BN) == 0)\
57  	{\
58  		MP = (struct metapage *)&JFS_IP(IP)->bxflag;\
59  		P = (TYPE *)&JFS_IP(IP)->ROOT;\
60  		RC = 0;\
61  	}\
62  	else\
63  	{\
64  		MP = read_metapage((IP), BN, SIZE, 1);\
65  		if (MP) {\
66  			RC = 0;\
67  			P = (MP)->data;\
68  		} else {\
69  			P = NULL;\
70  			jfs_err("bread failed!");\
71  			RC = -EIO;\
72  		}\
73  	}\
74  }
75  
76  #define BT_MARK_DIRTY(MP, IP)\
77  {\
78  	if (BT_IS_ROOT(MP))\
79  		mark_inode_dirty(IP);\
80  	else\
81  		mark_metapage_dirty(MP);\
82  }
83  
84  /* put the page buffer */
85  #define BT_PUTPAGE(MP)\
86  {\
87  	if (! BT_IS_ROOT(MP)) \
88  		release_metapage(MP); \
89  }
90  
91  
92  /*
93   *	btree traversal stack
94   *
95   * record the path traversed during the search;
96   * top frame record the leaf page/entry selected.
97   */
98  struct btframe {	/* stack frame */
99  	s64 bn;			/* 8: */
100  	s16 index;		/* 2: */
101  	s16 lastindex;		/* 2: unused */
102  	struct metapage *mp;	/* 4/8: */
103  };				/* (16/24) */
104  
105  struct btstack {
106  	struct btframe *top;
107  	int nsplit;
108  	struct btframe stack[MAXTREEHEIGHT];
109  };
110  
111  #define BT_CLR(btstack)\
112  	(btstack)->top = (btstack)->stack
113  
114  #define BT_STACK_FULL(btstack)\
115  	( (btstack)->top == &((btstack)->stack[MAXTREEHEIGHT-1]))
116  
117  #define BT_PUSH(BTSTACK, BN, INDEX)\
118  {\
119  	assert(!BT_STACK_FULL(BTSTACK));\
120  	(BTSTACK)->top->bn = BN;\
121  	(BTSTACK)->top->index = INDEX;\
122  	++(BTSTACK)->top;\
123  }
124  
125  #define BT_POP(btstack)\
126  	( (btstack)->top == (btstack)->stack ? NULL : --(btstack)->top )
127  
128  #define BT_STACK(btstack)\
129  	( (btstack)->top == (btstack)->stack ? NULL : (btstack)->top )
130  
BT_STACK_DUMP(struct btstack * btstack)131  static inline void BT_STACK_DUMP(struct btstack *btstack)
132  {
133  	int i;
134  	printk("btstack dump:\n");
135  	for (i = 0; i < MAXTREEHEIGHT; i++)
136  		printk(KERN_ERR "bn = %Lx, index = %d\n",
137  		       (long long)btstack->stack[i].bn,
138  		       btstack->stack[i].index);
139  }
140  
141  /* retrieve search results */
142  #define BT_GETSEARCH(IP, LEAF, BN, MP, TYPE, P, INDEX, ROOT)\
143  {\
144  	BN = (LEAF)->bn;\
145  	MP = (LEAF)->mp;\
146  	if (BN)\
147  		P = (TYPE *)MP->data;\
148  	else\
149  		P = (TYPE *)&JFS_IP(IP)->ROOT;\
150  	INDEX = (LEAF)->index;\
151  }
152  
153  /* put the page buffer of search */
154  #define BT_PUTSEARCH(BTSTACK)\
155  {\
156  	if (! BT_IS_ROOT((BTSTACK)->top->mp))\
157  		release_metapage((BTSTACK)->top->mp);\
158  }
159  #endif				/* _H_JFS_BTREE */
160