X-Git-Url: http://review.tizen.org/git/?a=blobdiff_plain;f=extent-cache.h;h=82db7fa3e46399d6dfa04c038c2d6b549c25ecda;hb=feccd7a8180f3f0f48ca23692ad5f71783163450;hp=a9d07e183eb81e3703cdd1ba4fce988a5fe78d39;hpb=378eacf815893cad989463b0917dcd2dd6553438;p=platform%2Fupstream%2Fbtrfs-progs.git

diff --git a/extent-cache.h b/extent-cache.h
index a9d07e1..82db7fa 100644
--- a/extent-cache.h
+++ b/extent-cache.h
@@ -16,8 +16,8 @@
  * Boston, MA 021110-1307, USA.
  */
 
-#ifndef __EXTENT_CACHE_H__
-#define __EXTENT_CACHE_H__
+#ifndef __BTRFS_EXTENT_CACHE_H__
+#define __BTRFS_EXTENT_CACHE_H__
 
 #if BTRFS_FLAT_INCLUDES
 #include "kerncompat.h"
@@ -45,11 +45,31 @@ struct cache_extent *last_cache_extent(struct cache_tree *tree);
 struct cache_extent *prev_cache_extent(struct cache_extent *pe);
 struct cache_extent *next_cache_extent(struct cache_extent *pe);
 
+/*
+ * Find a cache_extent which covers start.
+ *
+ * If not found, return next cache_extent if possible.
+ */
 struct cache_extent *search_cache_extent(struct cache_tree *tree, u64 start);
+
+/*
+ * Find a cache_extent which restrictly covers start.
+ *
+ * If not found, return NULL.
+ */
 struct cache_extent *lookup_cache_extent(struct cache_tree *tree,
 					 u64 start, u64 size);
 
+/*
+ * Add an non-overlap extent into cache tree
+ *
+ * If [start, start+size) overlap with existing one, it will return -EEXIST.
+ */
 int add_cache_extent(struct cache_tree *tree, u64 start, u64 size);
+
+/*
+ * Same with add_cache_extent, but with cache_extent strcut.
+ */
 int insert_cache_extent(struct cache_tree *tree, struct cache_extent *pe);
 void remove_cache_extent(struct cache_tree *tree, struct cache_extent *pe);
 
@@ -71,12 +91,31 @@ static void free_##name##_tree(struct cache_tree *tree)		\
 
 void free_extent_cache_tree(struct cache_tree *tree);
 
+/*
+ * Search a cache_extent with same objectid, and covers start.
+ *
+ * If not found, return next if possible.
+ */
 struct cache_extent *search_cache_extent2(struct cache_tree *tree,
 					  u64 objectid, u64 start);
+/*
+ * Search a cache_extent with same objectid, and covers the range
+ * [start, start + size)
+ *
+ * If not found, return next cache_extent if possible.
+ */
 struct cache_extent *lookup_cache_extent2(struct cache_tree *tree,
 					  u64 objectid, u64 start, u64 size);
 int add_cache_extent2(struct cache_tree *tree,
 		      u64 objectid, u64 start, u64 size);
 int insert_cache_extent2(struct cache_tree *tree, struct cache_extent *pe);
 
+/*
+ * Insert a cache_extent range [start, start + size).
+ *
+ * This function may merge with existing cache_extent.
+ * NOTE: caller must ensure the inserted range won't cover with any existing
+ * range.
+ */
+int add_merge_cache_extent(struct cache_tree *tree, u64 start, u64 size);
 #endif