How to diagnose and fix a problem if cannot log-in?

I am getting the following message on the site:

Warning: file_exists() [function.file-exists]: open_basedir restriction in effect. File(/var/www/domains/x.chichakli.com/docs/wp-content/plugins//../../../../../../../../../../../../../../../../../../tmp/ro8kbsmawgeht.txt) is not within the allowed path(s): (/var/www/domains/x.chichakli.com/:/usr/share/phpmyadmin:/etc/phpmyadmin:/var/www/myfilemanager:/var/www/myinstaller:/usr/local/lib/php) in /var/www/domains/x.chichakli.com/docs/wp-settings.php on line 115

However, if I try to log in I cannot; the log-in page no longer show up. Anyone can help?

Thanks