Btrfs: Add additional debugging for metadata checksum failures

Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index 16d67a6..d9f5bc4 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -216,4 +216,6 @@
 		      unsigned long *map_start,
 		      unsigned long *map_len, int km);
 void unmap_extent_buffer(struct extent_buffer *eb, char *token, int km);
+int invalidate_extent_lru(struct extent_io_tree *tree, u64 start,
+			  unsigned long len);
 #endif