btrfs_drop_extents doesn't change file extent's ram_bytes
in the case of booked extent. To be consistent, we should
also not change ram_bytes when truncating existing extent.
Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
                                        inode_sub_bytes(inode, old_num -
                                                        new_num);
                                }
-                               if (!compression && !encryption) {
-                                       btrfs_set_file_extent_ram_bytes(leaf,
-                                                       extent, new_num);
-                               }
                                btrfs_set_file_extent_num_bytes(leaf,
                                                        extent, new_num);
                                btrfs_mark_buffer_dirty(leaf);