1 files changed, 45 insertions, 0 deletions
diff --git a/fs/ext4/extents_status.h b/fs/ext4/extents_status.h
new file mode 100644
index 000000000000..077f82db092a
--- /dev/null
+++ b/fs/ext4/extents_status.h
@@ -0,0 +1,45 @@
+/*
+ *  fs/ext4/extents_status.h
+ *
+ * Written by Yongqiang Yang <[email protected]>
+ * Modified by
+ *	Allison Henderson <[email protected]>
+ *	Zheng Liu <[email protected]>
+ *
+ */
+
+#ifndef _EXT4_EXTENTS_STATUS_H
+#define _EXT4_EXTENTS_STATUS_H
+
+/*
+ * Turn on ES_DEBUG__ to get lots of info about extent status operations.
+ */
+#ifdef ES_DEBUG__
+#define es_debug(fmt, ...)	printk(fmt, ##__VA_ARGS__)
+#else
+#define es_debug(fmt, ...)	no_printk(fmt, ##__VA_ARGS__)
+#endif
+
+struct extent_status {
+	struct rb_node rb_node;
+	ext4_lblk_t start;	/* first block extent covers */
+	ext4_lblk_t len;	/* length of extent in block */
+};
+
+struct ext4_es_tree {
+	struct rb_root root;
+	struct extent_status *cache_es;	/* recently accessed extent */
+};
+
+extern int __init ext4_init_es(void);
+extern void ext4_exit_es(void);
+extern void ext4_es_init_tree(struct ext4_es_tree *tree);
+
+extern int ext4_es_insert_extent(struct inode *inode, ext4_lblk_t start,
+				 ext4_lblk_t len);
+extern int ext4_es_remove_extent(struct inode *inode, ext4_lblk_t start,
+				 ext4_lblk_t len);
+extern ext4_lblk_t ext4_es_find_extent(struct inode *inode,
+				struct extent_status *es);
+
+#endif /* _EXT4_EXTENTS_STATUS_H */