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-rw-r--r--fs/jfs/jfs_btree.h172
1 files changed, 172 insertions, 0 deletions
diff --git a/fs/jfs/jfs_btree.h b/fs/jfs/jfs_btree.h
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+++ b/fs/jfs/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 */