CIFS POSIX Extensions

configname: CONFIG_CIFS_POSIX

Linux Kernel Configuration
└─>File systems
└─>Network File Systems
└─>CIFS POSIX Extensions
In linux kernel since version 2.6.20 (release Date: 2007-02-04)  
Enabling this option will cause the cifs client to attempt to
negotiate a newer dialect with servers, such as Samba 3.0.5
or later, that optionally can handle more POSIX like (rather
than Windows like) file behavior. It also enables
support for POSIX ACLs (getfacl and setfacl) to servers
(such as Samba 3.10 and later) which can negotiate
CIFS POSIX ACL support. If unsure, say N.