[PATCH 25/52] Introduce interval tree basic data structures

[Vivek Goyal]

We want to use interval tree to keep track of per inode dax mappings.
Introduce basic data structures.

Signed-off-by: Vivek Goyal <vgoyal@xxxxxxxxxx>
---
 fs/fuse/fuse_i.h | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index fb49ca9d05ac..a24f31156b47 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -97,11 +97,22 @@ struct fuse_forget_link {
 	struct fuse_forget_link *next;
 };
 
+#define START(node) ((node)->start)
+#define LAST(node) ((node)->end)
+
 /** Translation information for file offsets to DAX window offsets */
 struct fuse_dax_mapping {
 	/* Will connect in fc->free_ranges to keep track of free memory */
 	struct list_head list;
 
+	/* For interval tree in file/inode */
+	struct rb_node rb;
+	/** Start Position in file */
+	__u64 start;
+	/** End Position in file */
+	__u64 end;
+	__u64 __subtree_last;
+
        /** Position in DAX window */
        u64 window_offset;
 
@@ -191,6 +202,10 @@ struct fuse_inode {
 
 	/** Lock for serializing lookup and readdir for back compatibility*/
 	struct mutex mutex;
+
+	/** Sorted rb tree of struct fuse_dax_mapping elements */
+	struct rb_root_cached dmap_tree;
+	unsigned long nr_dmaps;
 };
 
 /** FUSE inode state bits */
-- 
2.13.6