Btrfs: Simplify device selection for mirrored reads

Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 593011e..cc0d7f3 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -640,7 +640,7 @@
 	if (!path)
 		return -ENOMEM;
 
-	path->reada = 0;
+	path->reada = 1;
 	key.objectid = bytenr;
 	btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
 	key.offset = num_bytes;
@@ -660,7 +660,7 @@
 
 	btrfs_release_path(root->fs_info->extent_root, path);
 
-	path->reada = 0;
+	path->reada = 1;
 	ret = btrfs_insert_extent_backref(trans, root->fs_info->extent_root,
 					  path, bytenr, root_objectid,
 					  ref_generation, owner, owner_offset);
@@ -692,7 +692,7 @@
 
 	WARN_ON(num_bytes < root->sectorsize);
 	path = btrfs_alloc_path();
-	path->reada = 0;
+	path->reada = 1;
 	key.objectid = bytenr;
 	key.offset = num_bytes;
 	btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
@@ -1328,7 +1328,7 @@
 	if (!path)
 		return -ENOMEM;
 
-	path->reada = 0;
+	path->reada = 1;
 	ret = lookup_extent_backref(trans, extent_root, path,
 				    bytenr, root_objectid,
 				    ref_generation,