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Diffstat (limited to 'fs/jfs/jfs_btree.h')
| -rw-r--r-- | fs/jfs/jfs_btree.h | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/fs/jfs/jfs_btree.h b/fs/jfs/jfs_btree.h new file mode 100644 index 000000000..79c61805b --- /dev/null +++ b/fs/jfs/jfs_btree.h @@ -0,0 +1,172 @@ +/* + * 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 */ |