Only Mac clients are affected? Have you tested a Linux (e.g. Fedora 25 live OS would do) client? It's necessary for all files to have selinux context system_u:object_r:samba_share_t:s0. You can either user chcon -R to apply it recursively to a particular directory you're sharing, or if it's an entire (dedicated) volume, you can apply it volume wide with a mount option, 'mount -o context="system_u:object_r:samba_share_t:s0" /dev/mapper/brick /brick' I'm not doing anything different for my Mac client than for a Linux one, at least not that I'm aware of; however I'm using samba-4.5.3 since I'm using Fedora 25 server. It may be that older versions need to force a lower version of SMB depending on which Mac client you're using. Chris Murphy