By default regular files are created with mode "rw-r-
r-", which is similar as that on many UNIX platforms. However, setting execution bit for regular files are not supported by HDFS.
It's the client's choice to set file access mode. HDFS would be easier to use if it can support it, especially when HDFS is accessed by network file system protocols. This JIRA is to track the change to support execution bit.