Btrfs: Add an extent buffer LRU to reduce radix tree hits

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 9 insertions, 7 deletions

diff --git a/fs/btrfs/extent_map.h b/fs/btrfs/extent_map.h
index 8409b5cbeda7..52a8b9394fc6 100644
--- a/fs/btrfs/extent_map.h
+++ b/fs/btrfs/extent_map.h
@@ -16,6 +16,7 @@
 #define EXTENT_DELALLOC (1 << 5)
 #define EXTENT_DEFRAG (1 << 6)
 #define EXTENT_DEFRAG_DONE (1 << 7)
+#define EXTENT_BUFFER_FILLED (1 << 8)
 #define EXTENT_IOBITS (EXTENT_LOCKED | EXTENT_WRITEBACK)
 
 
@@ -33,6 +34,9 @@ struct extent_map_tree {
         struct address_space *mapping;
         rwlock_t lock;
         struct extent_map_ops *ops;
+        spinlock_t lru_lock;
+        struct list_head buffer_lru;
+        int lru_size;
 };
 
 /* note, this must start with the same fields as fs/extent_map.c:tree_entry */
@@ -64,20 +68,17 @@ struct extent_state {
         struct list_head list;
 };
 
-#define EXTENT_INLINE_PAGES 32
 struct extent_buffer {
         u64 start;
         unsigned long len;
-        atomic_t refs;
-        int flags;
-        struct list_head list;
-        struct list_head leak_list;
-        unsigned long alloc_addr;
         char *map_token;
         char *kaddr;
         unsigned long map_start;
         unsigned long map_len;
-        struct page *pages[EXTENT_INLINE_PAGES];
+        struct page *last_page;
+        struct list_head lru;
+        atomic_t refs;
+        int flags;
 };
 
 typedef struct extent_map *(get_extent_t)(struct inode *inode,
@@ -88,6 +89,7 @@ typedef struct extent_map *(get_extent_t)(struct inode *inode,
 
 void extent_map_tree_init(struct extent_map_tree *tree,
                           struct address_space *mapping, gfp_t mask);
+void extent_map_tree_cleanup(struct extent_map_tree *tree);
 struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
                                          u64 start, u64 end);
 int add_extent_mapping(struct extent_map_tree *tree,