apache如何设置php权限

<?php
$logging = <<< LOG
This is a test
LOG;
$testfile = fopen(&#39;/home/djameson/test.txt&#39;, &#39;a&#39;); 
fwrite ($testfile, $logging);
fclose($testfile);
?>

Warning: fopen(/home/djameson/test.txt): failed to open stream: Permission denied in   /var/www/html/fileio_test/io_test.php on line 7
Warning: fwrite() expects parameter 1 to be resource, boolean given in /var/www/html/fileio_test/io_test.php on line 8
Warning: fclose() expects parameter 1 to be resource, boolean given in /var/www/html/fileio_test/io_test.php on line 9

chmod 0777 /home/djameson/test.txt

Sudo chown www-data:www-data /home/djameson/test.txt
chmod 0744 /home/djameson/test.txt

Sudo usermod -a -G www-data djameson
chmod 0764 /home/djameson/test.txt