Btrfs: Do more extensive readahead during tree searches

Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 3984841..7e4cf62 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -827,7 +827,7 @@
 	btrfs_set_key_type(&key, key_type);
 	key.offset = filp->f_pos;
 	path = btrfs_alloc_path();
-	path->reada = 1;
+	path->reada = 2;
 	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
 	if (ret < 0)
 		goto err;