Samba permissions-simplified
Samba comes with different types of permissions for share. Try to remember few things about UNIX and Samba permissions.
(a) Linux system permissions take precedence over Samba permissions. For example if a directory does not have Linux write permission, setting samba writeable = Yes (see below) will not allow to write to shared directory / share.
(b) The filesystem permission cannot be take priority over Samba permission. For example if filesystem mounted as readonly setting writeable = Yes will not allow to write to any shared directory or share via samba server.
In short (thanks to Craig [see below in comment section]) :
Limits set by kernel-level access control such as file permissions, file system mount options, ACLs, and SELinux policies cannot be overridden by Samba. Both the kernel and Samba must permit the user to perform an action on a file before that action can occur.
Samba mask permission
It is also possible to specify samba default file creation permission using mask.
* create mask: This option is set using an octal value when setting permissions for files.
* directory mask: Directories must have the execute bit for proper access. Default parameter is 0755.</div>
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