Tez may skip file permission update on intermediate output

Before updating file permissions TEZ check if the permission change is needed with the following conditional:

if (!SPILL_FILE_PERMS.equals(SPILL_FILE_PERMS.applyUMask(FsPermission.getUMask(conf)))) {
  rfs.setPermission(filename, SPILL_FILE_PERMS);
} 

If the config object is changing in the background then setPermission() call will be skipped.

The rfs file system is always a local file system so there is no need to do this check beforehand (it doesn't generate an additional NameNode call).

rfs = ((LocalFileSystem)FileSystem.getLocal(this.conf)).getRaw(); 

 We can remove the if statement and do the permission change unconditionally.