This is the client VFS module for the Common Internet File System (CIFS) protocol which is the successor to the Server Message Block (SMB) protocol, the native file sharing mechanism for most early PC operating systems. The CIFS protocol is fully supported by file servers such as Windows 2000 (including Windows 2003, NT 4 and Windows XP) as well by Samba (which provides excellent CIFS server support for Linux and many other operating systems). Limited support for OS/2 and Windows ME and similar servers is provided as well. The cifs module provides an advanced network file system client for mounting to CIFS compliant servers. It includes support for DFS (hierarchical name space), secure per-user session establishment via Kerberos or NTLM or NTLMv2, safe distributed caching (oplock), optional packet signing, Unicode and other internationalization improvements. If you need to mount to Samba or Windows from this machine, say Y.
Enabling this option will cause statistics for each server share mounted by the cifs client to be displayed in /proc/fs/cifs/Stats
Enabling this option will allow more detailed statistics on SMB request timing to be displayed in /proc/fs/cifs/DebugData and also allow optional logging of slow responses to dmesg (depending on the value of /proc/fs/cifs/cifsFYI, see fs/cifs/README for more details). These additional statistics may have a minor effect on performance and memory utilization. Unless you are a developer or are doing network performance analysis or tuning, say N.
Modern CIFS servers including Samba and most Windows versions (since 1997) support stronger NTLM (and even NTLMv2 and Kerberos) security mechanisms. These hash the password more securely than the mechanisms used in the older LANMAN version of the SMB protocol but LANMAN based authentication is needed to establish sessions with some old SMB servers. Enabling this option allows the cifs module to mount to older LANMAN based servers such as OS/2 and Windows 95, but such mounts may be less secure than mounts using NTLM or more recent security mechanisms if you are on a public network. Unless you have a need to access old SMB servers (and are on a private network) you probably want to say N. Even if this support is enabled in the kernel build, LANMAN authentication will not be used automatically. At runtime LANMAN mounts are disabled but can be set to required (or optional) either in /proc/fs/cifs (see fs/cifs/README for more detail) or via an option on the mount command. This support is disabled by default in order to reduce the possibility of a downgrade attack. If unsure, say N.
Enables an upcall mechanism for CIFS which accesses userspace helper utilities to provide SPNEGO packaged (RFC 4178) Kerberos tickets which are needed to mount to certain secure servers (for which more secure Kerberos authentication is required). If unsure, say N.
Extended attributes are name:value pairs associated with inodes by the kernel or by users (see the attr(5) manual page, or visit <http://acl.bestbits.at/> for details). CIFS maps the name of extended attributes beginning with the user namespace prefix to SMB/CIFS EAs. EAs are stored on Windows servers without the user namespace prefix, but their names are seen by Linux cifs clients prefaced by the user namespace prefix. The system namespace (used by some filesystems to store ACLs) is not supported at this time. If unsure, say N.
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.
Enabling this option adds a few more debugging routines to the cifs code which slightly increases the size of the cifs module and can cause additional logging of debug messages in some error paths, slowing performance. This option can be turned off unless you are debugging cifs problems. If unsure, say N.
Distributed File System (DFS) support is used to access shares transparently in an enterprise name space, even if the share moves to a different server. This feature also 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.
Makes CIFS FS-Cache capable. Say Y here if you want your CIFS data to be cached locally on disk through the general filesystem cache manager. If unsure, say N.
Allows to fetch CIFS/NTFS ACL from the server. The DACL blob is handed over to the application/caller.
Allows NFS server to export a CIFS mounted share (nfsd over cifs)