Shared Folders vs CIFS/SMB Share

Yes, I am talking Samba shares here. When you create a shared folder the default drop down is chmod 775 (i.e. owner r/w/e, user r/w/e and others read only). This is good for say a media folder. So you create a media folder and then share it with Samba. Then you connect to the share from say a Windows machine. While connected you can create a Music, Movies, Photos, etc... folders. Because the folder is media folder is chmod 775 and anything created in the media folder by users given permission will be chmod 775 and chown will be owner:users (the person that created will be the owner). Don't pay attention to whether a file is executable as the data drives are mounted noexec.

With minidlna you can just select the media folder SMB share and use all media types. With plex you can select an individual folder like Movies via their tree selection. Since the folders and contents are 775 others is read only and this is all plex and minidlna need. For something like Transmission you should create a script that can be run at the end of the download that will move the files to another folder and change chmod & chown to appropriate for the folder where you would like content. There is an entry where you can put script you want in the settings. Make sure script is on the system drive as it needs to be executable.