Port extent buffer to btrfs-progs

This patch ports extent buffer to btrfs-progs. extent_map.c contains a
simplified extent map tree and functions that manipulate/manage extent
buffer. extent state related codes are based on corresponding codes in
kernel module, codes that manage extent buffer are from disk-io.c.

1 files changed, 1 insertions, 0 deletions

diff --git a/extent-cache.h b/extent-cache.h
index 9e933752..4c468cea 100644
--- a/extent-cache.h
+++ b/extent-cache.h
@@ -36,6 +36,7 @@ void remove_cache_extent(struct cache_tree *tree,
 			  struct cache_extent *pe);
 struct cache_extent *find_first_cache_extent(struct cache_tree *tree,
 						 u64 start);
+struct cache_extent *prev_cache_extent(struct cache_extent *pe);
 struct cache_extent *next_cache_extent(struct cache_extent *pe);
 struct cache_extent *find_cache_extent(struct cache_tree *tree,
 					   u64 start, u64 size);