diff --git a/fs/ocfs2/slot_map.h b/fs/ocfs2/slot_map.h
new file mode 100644
index 0000000..d8c8cee
--- /dev/null
+++ b/fs/ocfs2/slot_map.h
@@ -0,0 +1,66 @@
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * slotmap.h
+ *
+ * description here
+ *
+ * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
+ *
+ * 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 021110-1307, USA.
+ */
+
+
+#ifndef SLOTMAP_H
+#define SLOTMAP_H
+
+struct ocfs2_slot_info {
+	spinlock_t si_lock;
+
+       	struct inode *si_inode;
+	struct buffer_head *si_bh;
+	unsigned int si_num_slots;
+	unsigned int si_size;
+	s16 si_global_node_nums[OCFS2_MAX_SLOTS];
+};
+
+int ocfs2_init_slot_info(struct ocfs2_super *osb);
+void ocfs2_free_slot_info(struct ocfs2_slot_info *si);
+
+int ocfs2_find_slot(struct ocfs2_super *osb);
+void ocfs2_put_slot(struct ocfs2_super *osb);
+
+void ocfs2_update_slot_info(struct ocfs2_slot_info *si);
+int ocfs2_update_disk_slots(struct ocfs2_super *osb,
+			    struct ocfs2_slot_info *si);
+
+s16 ocfs2_node_num_to_slot(struct ocfs2_slot_info *si,
+			   s16 global);
+void ocfs2_clear_slot(struct ocfs2_slot_info *si,
+		      s16 slot_num);
+
+void ocfs2_populate_mounted_map(struct ocfs2_super *osb);
+
+static inline int ocfs2_is_empty_slot(struct ocfs2_slot_info *si,
+				      int slot_num)
+{
+	BUG_ON(slot_num == OCFS2_INVALID_SLOT);
+	assert_spin_locked(&si->si_lock);
+
+	return si->si_global_node_nums[slot_num] == OCFS2_INVALID_SLOT;
+}
+
+#endif