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 000000000000..7f3e9ac454ff
--- /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 */