Problem ojs 3.0.2 on centos7

[ctgraham]

Please review this FAQ for the specifics of how permissions should be set:

How should file permissions be set?

There isn’t a straightforward answer because so much depends on your hosting environment. Start with your hosting provider’s documentation and support, or with your system administrator, and with the following instructions: How to set your permissions In general, you want your permissions set such that your webserver can read and write (recursively) to config.inc.php's files_dir, and to ./cache/, and ./public/. Optionally, for added features and reduced security, you can enable write to confi…

One thing this FAQ does not cover is selinux, which may be enabled by default in RHEL7/CENTOS7. If selinux is enabled, you will also need to set the selinux context for each writable directory to allow the webserver to write.
https://wiki.centos.org/HowTos/SELinux