jfs_btree.h
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/*
* Copyright (C) International Business Machines Corp., 2000-2004
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
* the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef _H_JFS_BTREE
#define _H_JFS_BTREE
/*
* jfs_btree.h: B+-tree
*
* JFS B+-tree (dtree and xtree) common definitions
*/
/*
* basic btree page - btpage
*
struct btpage {
s64 next; right sibling bn
s64 prev; left sibling bn
u8 flag;
u8 rsrvd[7]; type specific
s64 self; self address
u8 entry[4064];
}; */
/* btpaget_t flag */
#define BT_TYPE 0x07 /* B+-tree index */
#define BT_ROOT 0x01 /* root page */
#define BT_LEAF 0x02 /* leaf page */
#define BT_INTERNAL 0x04 /* internal page */
#define BT_RIGHTMOST 0x10 /* rightmost page */
#define BT_LEFTMOST 0x20 /* leftmost page */
#define BT_SWAPPED 0x80 /* used by fsck for endian swapping */
/* btorder (in inode) */
#define BT_RANDOM 0x0000
#define BT_SEQUENTIAL 0x0001
#define BT_LOOKUP 0x0010
#define BT_INSERT 0x0020
#define BT_DELETE 0x0040
/*
* btree page buffer cache access
*/
#define BT_IS_ROOT(MP) (((MP)->xflag & COMMIT_PAGE) == 0)
/* get page from buffer page */
#define BT_PAGE(IP, MP, TYPE, ROOT)\
(BT_IS_ROOT(MP) ? (TYPE *)&JFS_IP(IP)->ROOT : (TYPE *)(MP)->data)
/* get the page buffer and the page for specified block address */
#define BT_GETPAGE(IP, BN, MP, TYPE, SIZE, P, RC, ROOT)\
{\
if ((BN) == 0)\
{\
MP = (struct metapage *)&JFS_IP(IP)->bxflag;\
P = (TYPE *)&JFS_IP(IP)->ROOT;\
RC = 0;\
}\
else\
{\
MP = read_metapage((IP), BN, SIZE, 1);\
if (MP) {\
RC = 0;\
P = (MP)->data;\
} else {\
P = NULL;\
jfs_err("bread failed!");\
RC = -EIO;\
}\
}\
}
#define BT_MARK_DIRTY(MP, IP)\
{\
if (BT_IS_ROOT(MP))\
mark_inode_dirty(IP);\
else\
mark_metapage_dirty(MP);\
}
/* put the page buffer */
#define BT_PUTPAGE(MP)\
{\
if (! BT_IS_ROOT(MP)) \
release_metapage(MP); \
}
/*
* btree traversal stack
*
* record the path traversed during the search;
* top frame record the leaf page/entry selected.
*/
struct btframe { /* stack frame */
s64 bn; /* 8: */
s16 index; /* 2: */
s16 lastindex; /* 2: unused */
struct metapage *mp; /* 4/8: */
}; /* (16/24) */
struct btstack {
struct btframe *top;
int nsplit;
struct btframe stack[MAXTREEHEIGHT];
};
#define BT_CLR(btstack)\
(btstack)->top = (btstack)->stack
#define BT_STACK_FULL(btstack)\
( (btstack)->top == &((btstack)->stack[MAXTREEHEIGHT-1]))
#define BT_PUSH(BTSTACK, BN, INDEX)\
{\
assert(!BT_STACK_FULL(BTSTACK));\
(BTSTACK)->top->bn = BN;\
(BTSTACK)->top->index = INDEX;\
++(BTSTACK)->top;\
}
#define BT_POP(btstack)\
( (btstack)->top == (btstack)->stack ? NULL : --(btstack)->top )
#define BT_STACK(btstack)\
( (btstack)->top == (btstack)->stack ? NULL : (btstack)->top )
static inline void BT_STACK_DUMP(struct btstack *btstack)
{
int i;
printk("btstack dump:\n");
for (i = 0; i < MAXTREEHEIGHT; i++)
printk(KERN_ERR "bn = %Lx, index = %d\n",
(long long)btstack->stack[i].bn,
btstack->stack[i].index);
}
/* retrieve search results */
#define BT_GETSEARCH(IP, LEAF, BN, MP, TYPE, P, INDEX, ROOT)\
{\
BN = (LEAF)->bn;\
MP = (LEAF)->mp;\
if (BN)\
P = (TYPE *)MP->data;\
else\
P = (TYPE *)&JFS_IP(IP)->ROOT;\
INDEX = (LEAF)->index;\
}
/* put the page buffer of search */
#define BT_PUTSEARCH(BTSTACK)\
{\
if (! BT_IS_ROOT((BTSTACK)->top->mp))\
release_metapage((BTSTACK)->top->mp);\
}
#endif /* _H_JFS_BTREE */