DFS feature support (EXPERIMENTAL)

configname: CONFIG_CIFS_DFS_UPCALL

Linux Kernel Configuration
└─>File systems
└─>Network File Systems
└─>DFS feature support (EXPERIMENTAL)
In linux kernel since version 2.6.25 (release Date: 2008-04-16)  
Enables an upcall mechanism for CIFS which contacts userspace
helper utilities to provide server name resolution (host names to
IP addresses) which is needed for implicit mounts of DFS junction
points. If unsure, say N.