1 files changed, 159 insertions, 0 deletions
diff --git a/fs/jfs/jfs_btree.h b/fs/jfs/jfs_btree.h
new file mode 100644
index 000000000..ce055ef50
--- /dev/null
+++ b/fs/jfs/jfs_btree.h
@@ -0,0 +1,159 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ *   Copyright (C) International Business Machines Corp., 2000-2004
+ */
+#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 */