FreeBSD/Linux Kernel Cross Reference
sys/fs/cifs/

	Name	Size	Last modified (GMT)	Description
	Parent directory		2013-02-02 13:04:12
	AUTHORS	2631 bytes	2011-08-10 17:04:25
	CHANGES	47316 bytes	2010-08-24 17:15:26
	Kconfig	7661 bytes	2012-12-25 01:45:29
	Makefile	625 bytes	2012-12-25 01:45:29
	README	39192 bytes	2012-12-25 01:45:29
	TODO	5334 bytes	2011-08-10 17:04:25
	asn1.c	15302 bytes	2010-08-24 17:15:26
	cache.c	8132 bytes	2012-12-25 01:45:29
	cifs_debug.c	17583 bytes	2012-12-25 01:45:29
	cifs_debug.h	2709 bytes	2012-12-25 01:45:29
	cifs_dfs_ref.c	9774 bytes	2013-02-02 13:01:57
	cifs_fs_sb.h	3160 bytes	2012-12-25 01:45:29
	cifs_spnego.c	4907 bytes	2012-12-25 01:45:29
	cifs_spnego.h	1625 bytes	2011-08-10 17:04:25
	cifs_unicode.c	11416 bytes	2012-12-25 01:45:29
	cifs_unicode.h	9339 bytes	2012-12-25 01:45:29
	cifs_uniupr.h	12866 bytes	2011-08-10 17:04:25
	cifsacl.c	29388 bytes	2012-12-25 01:45:29
	cifsacl.h	2929 bytes	2012-12-25 01:45:29
	cifsencrypt.c	22794 bytes	2012-12-25 01:45:29
	cifsencrypt.h	1256 bytes	2009-10-05 12:45:23
	cifsfs.c	32679 bytes	2013-02-02 13:01:57
	cifsfs.h	5857 bytes	2012-12-25 01:45:29
	cifsglob.h	49345 bytes	2013-02-02 13:01:57
	cifspdu.h	82706 bytes	2012-12-25 01:45:29
	cifsproto.h	22708 bytes	2012-12-25 01:45:29
	cifssmb.c	193118 bytes	2012-12-25 01:45:30
	cn_cifs.h	1323 bytes	2006-12-13 12:00:45
	connect.c	108411 bytes	2013-02-02 13:01:57
	dir.c	22509 bytes	2012-12-25 01:45:30
	dns_resolve.c	2856 bytes	2011-08-10 17:04:26
	dns_resolve.h	1220 bytes	2010-08-24 17:15:26
	export.c	2417 bytes	2012-12-25 01:45:30
	fcntl.c	3722 bytes	2008-05-16 14:23:38
	file.c	95451 bytes	2013-02-02 13:01:57
	fscache.c	6533 bytes	2011-08-10 17:04:26
	fscache.h	4562 bytes	2011-08-10 17:04:26
	inode.c	60037 bytes	2012-12-25 01:45:31
	ioctl.c	2712 bytes	2012-12-25 01:45:31
	link.c	15286 bytes	2012-12-25 01:45:31
	md4.c	4586 bytes	2008-03-10 12:24:51
	md5.c	11019 bytes	2009-10-05 12:45:23
	md5.h	1116 bytes	2009-10-05 12:45:23
	misc.c	17069 bytes	2012-12-25 01:45:31
	netmisc.c	40006 bytes	2012-12-25 01:45:31
	nterr.c	34315 bytes	2012-12-25 01:45:31
	nterr.h	30768 bytes	2012-12-25 01:45:31
	ntlmssp.h	5795 bytes	2012-12-25 01:45:31
	readdir.c	24893 bytes	2012-12-25 01:45:31
	rfc1002pdu.h	2881 bytes	2007-07-05 23:09:37
	sess.c	29287 bytes	2012-12-25 01:45:31
	smb1ops.c	29151 bytes	2013-02-02 13:01:57
	smb2file.c	7888 bytes	2012-12-25 01:45:31
	smb2glob.h	1787 bytes	2012-12-25 01:45:31
	smb2inode.c	7275 bytes	2012-12-25 01:45:31
	smb2maperror.c	129803 bytes	2012-12-25 01:45:31
	smb2misc.c	17505 bytes	2012-12-25 01:45:31
	smb2ops.c	22305 bytes	2013-02-02 13:01:57
	smb2pdu.c	60813 bytes	2012-12-25 01:45:31
	smb2pdu.h	27169 bytes	2012-12-25 01:45:31
	smb2proto.h	8084 bytes	2012-12-25 01:45:31
	smb2status.h	128176 bytes	2012-12-25 01:45:31
	smb2transport.c	8818 bytes	2012-12-25 01:45:31
	smbdes.c	10317 bytes	2010-08-24 17:15:26
	smbencrypt.c	6117 bytes	2012-12-25 01:45:31
	smberr.h	7651 bytes	2010-08-24 17:15:26
	smbfsctl.h	4827 bytes	2009-10-05 12:45:23
	transport.c	26903 bytes	2013-02-02 13:01:57
	xattr.c	11966 bytes	2012-12-25 01:45:31

     The CIFS VFS support for Linux supports many advanced network filesystem 
     features such as hierarchical dfs like namespace, hardlinks, locking and more.  
     It was designed to comply with the SNIA CIFS Technical Reference (which 
     supersedes the 1992 X/Open SMB Standard) as well as to perform best practice 
     practical interoperability with Windows 2000, Windows XP, Samba and equivalent 
     servers.  This code was developed in participation with the Protocol Freedom
     Information Foundation.
     
     Please see
      http://protocolfreedom.org/ and
      http://samba.org/samba/PFIF/
    for more details.
    
    
    For questions or bug reports please contact:
        sfrench@samba.org (sfrench@us.ibm.com) 
    
    Build instructions:
    ==================
    For Linux 2.4:
    1) Get the kernel source (e.g.from http://www.kernel.org)
    and download the cifs vfs source (see the project page
    at http://us1.samba.org/samba/Linux_CIFS_client.html)
    and change directory into the top of the kernel directory
    then patch the kernel (e.g. "patch -p1 < cifs_24.patch") 
    to add the cifs vfs to your kernel configure options if
    it has not already been added (e.g. current SuSE and UL
    users do not need to apply the cifs_24.patch since the cifs vfs is
    already in the kernel configure menu) and then
    mkdir linux/fs/cifs and then copy the current cifs vfs files from
    the cifs download to your kernel build directory e.g.
    
            cp <cifs_download_dir>/fs/cifs/* to <kernel_download_dir>/fs/cifs
            
    2) make menuconfig (or make xconfig)
    3) select cifs from within the network filesystem choices
    4) save and exit
    5) make dep
    6) make modules (or "make" if CIFS VFS not to be built as a module)
    
    For Linux 2.6:
    1) Download the kernel (e.g. from http://www.kernel.org)
    and change directory into the top of the kernel directory tree
    (e.g. /usr/src/linux-2.5.73)
    2) make menuconfig (or make xconfig)
    3) select cifs from within the network filesystem choices
    4) save and exit
    5) make
    
    
    Installation instructions:
    =========================
    If you have built the CIFS vfs as module (successfully) simply
    type "make modules_install" (or if you prefer, manually copy the file to
    the modules directory e.g. /lib/modules/2.4.10-4GB/kernel/fs/cifs/cifs.o).
    
    If you have built the CIFS vfs into the kernel itself, follow the instructions
    for your distribution on how to install a new kernel (usually you
    would simply type "make install").
    
    If you do not have the utility mount.cifs (in the Samba 3.0 source tree and on 
    the CIFS VFS web site) copy it to the same directory in which mount.smbfs and 
    similar files reside (usually /sbin).  Although the helper software is not  
    required, mount.cifs is recommended.  Eventually the Samba 3.0 utility program 
    "net" may also be helpful since it may someday provide easier mount syntax for
    users who are used to Windows e.g.
            net use <mount point> <UNC name or cifs URL>
    Note that running the Winbind pam/nss module (logon service) on all of your
    Linux clients is useful in mapping Uids and Gids consistently across the
    domain to the proper network user.  The mount.cifs mount helper can be
    trivially built from Samba 3.0 or later source e.g. by executing:
    
            gcc samba/source/client/mount.cifs.c -o mount.cifs
    
    If cifs is built as a module, then the size and number of network buffers
    and maximum number of simultaneous requests to one server can be configured.
    Changing these from their defaults is not recommended. By executing modinfo
            modinfo kernel/fs/cifs/cifs.ko
    on kernel/fs/cifs/cifs.ko the list of configuration changes that can be made
    at module initialization time (by running insmod cifs.ko) can be seen.
    
    Allowing User Mounts
    ====================
    To permit users to mount and unmount over directories they own is possible
    with the cifs vfs.  A way to enable such mounting is to mark the mount.cifs
    utility as suid (e.g. "chmod +s /sbin/mount.cifs). To enable users to 
    umount shares they mount requires
    1) mount.cifs version 1.4 or later
    2) an entry for the share in /etc/fstab indicating that a user may
    unmount it e.g.
    //server/usersharename  /mnt/username cifs user 0 0
    
    Note that when the mount.cifs utility is run suid (allowing user mounts), 
    in order to reduce risks, the "nosuid" mount flag is passed in on mount to
    disallow execution of an suid program mounted on the remote target.
    When mount is executed as root, nosuid is not passed in by default,
    and execution of suid programs on the remote target would be enabled
    by default. This can be changed, as with nfs and other filesystems, 
    by simply specifying "nosuid" among the mount options. For user mounts 
   though to be able to pass the suid flag to mount requires rebuilding 
   mount.cifs with the following flag: 
    
           gcc samba/source/client/mount.cifs.c -DCIFS_ALLOW_USR_SUID -o mount.cifs
   
   There is a corresponding manual page for cifs mounting in the Samba 3.0 and
   later source tree in docs/manpages/mount.cifs.8 
   
   Allowing User Unmounts
   ======================
   To permit users to ummount directories that they have user mounted (see above),
   the utility umount.cifs may be used.  It may be invoked directly, or if 
   umount.cifs is placed in /sbin, umount can invoke the cifs umount helper
   (at least for most versions of the umount utility) for umount of cifs
   mounts, unless umount is invoked with -i (which will avoid invoking a umount
   helper). As with mount.cifs, to enable user unmounts umount.cifs must be marked
   as suid (e.g. "chmod +s /sbin/umount.cifs") or equivalent (some distributions
   allow adding entries to a file to the /etc/permissions file to achieve the
   equivalent suid effect).  For this utility to succeed the target path
   must be a cifs mount, and the uid of the current user must match the uid
   of the user who mounted the resource.
   
   Also note that the customary way of allowing user mounts and unmounts is 
   (instead of using mount.cifs and unmount.cifs as suid) to add a line
   to the file /etc/fstab for each //server/share you wish to mount, but
   this can become unwieldy when potential mount targets include many
   or  unpredictable UNC names.
   
   Samba Considerations 
   ==================== 
   To get the maximum benefit from the CIFS VFS, we recommend using a server that 
   supports the SNIA CIFS Unix Extensions standard (e.g.  Samba 2.2.5 or later or 
   Samba 3.0) but the CIFS vfs works fine with a wide variety of CIFS servers.  
   Note that uid, gid and file permissions will display default values if you do 
   not have a server that supports the Unix extensions for CIFS (such as Samba 
   2.2.5 or later).  To enable the Unix CIFS Extensions in the Samba server, add 
   the line: 
   
           unix extensions = yes
           
   to your smb.conf file on the server.  Note that the following smb.conf settings 
   are also useful (on the Samba server) when the majority of clients are Unix or 
   Linux: 
   
           case sensitive = yes
           delete readonly = yes 
           ea support = yes
   
   Note that server ea support is required for supporting xattrs from the Linux
   cifs client, and that EA support is present in later versions of Samba (e.g. 
   3.0.6 and later (also EA support works in all versions of Windows, at least to
   shares on NTFS filesystems).  Extended Attribute (xattr) support is an optional
   feature of most Linux filesystems which may require enabling via
   make menuconfig. Client support for extended attributes (user xattr) can be
   disabled on a per-mount basis by specifying "nouser_xattr" on mount.
   
   The CIFS client can get and set POSIX ACLs (getfacl, setfacl) to Samba servers
   version 3.10 and later.  Setting POSIX ACLs requires enabling both XATTR and 
   then POSIX support in the CIFS configuration options when building the cifs
   module.  POSIX ACL support can be disabled on a per mount basic by specifying
   "noacl" on mount.
    
   Some administrators may want to change Samba's smb.conf "map archive" and 
   "create mask" parameters from the default.  Unless the create mask is changed
   newly created files can end up with an unnecessarily restrictive default mode,
   which may not be what you want, although if the CIFS Unix extensions are
   enabled on the server and client, subsequent setattr calls (e.g. chmod) can
   fix the mode.  Note that creating special devices (mknod) remotely 
   may require specifying a mkdev function to Samba if you are not using 
   Samba 3.0.6 or later.  For more information on these see the manual pages
   ("man smb.conf") on the Samba server system.  Note that the cifs vfs,
   unlike the smbfs vfs, does not read the smb.conf on the client system 
   (the few optional settings are passed in on mount via -o parameters instead).  
   Note that Samba 2.2.7 or later includes a fix that allows the CIFS VFS to delete
   open files (required for strict POSIX compliance).  Windows Servers already 
   supported this feature. Samba server does not allow symlinks that refer to files
   outside of the share, so in Samba versions prior to 3.0.6, most symlinks to
   files with absolute paths (ie beginning with slash) such as:
            ln -s /mnt/foo bar
   would be forbidden. Samba 3.0.6 server or later includes the ability to create 
   such symlinks safely by converting unsafe symlinks (ie symlinks to server 
   files that are outside of the share) to a samba specific format on the server
   that is ignored by local server applications and non-cifs clients and that will
   not be traversed by the Samba server).  This is opaque to the Linux client
   application using the cifs vfs. Absolute symlinks will work to Samba 3.0.5 or
   later, but only for remote clients using the CIFS Unix extensions, and will
   be invisbile to Windows clients and typically will not affect local
   applications running on the same server as Samba.  
   
   Use instructions:
   ================
   Once the CIFS VFS support is built into the kernel or installed as a module 
   (cifs.o), you can use mount syntax like the following to access Samba or Windows 
   servers: 
   
     mount -t cifs //9.53.216.11/e$ /mnt -o user=myname,pass=mypassword
   
   Before -o the option -v may be specified to make the mount.cifs
   mount helper display the mount steps more verbosely.  
   After -o the following commonly used cifs vfs specific options
   are supported:
   
     user=<username>
     pass=<password>
     domain=<domain name>
     
   Other cifs mount options are described below.  Use of TCP names (in addition to
   ip addresses) is available if the mount helper (mount.cifs) is installed. If
   you do not trust the server to which are mounted, or if you do not have
   cifs signing enabled (and the physical network is insecure), consider use
   of the standard mount options "noexec" and "nosuid" to reduce the risk of 
   running an altered binary on your local system (downloaded from a hostile server
   or altered by a hostile router).
   
   Although mounting using format corresponding to the CIFS URL specification is
   not possible in mount.cifs yet, it is possible to use an alternate format
   for the server and sharename (which is somewhat similar to NFS style mount
   syntax) instead of the more widely used UNC format (i.e. \\server\share):
     mount -t cifs tcp_name_of_server:share_name /mnt -o user=myname,pass=mypasswd
   
   When using the mount helper mount.cifs, passwords may be specified via alternate
   mechanisms, instead of specifying it after -o using the normal "pass=" syntax
   on the command line:
   1) By including it in a credential file. Specify credentials=filename as one
   of the mount options. Credential files contain two lines
           username=someuser
           password=your_password
   2) By specifying the password in the PASSWD environment variable (similarly
   the user name can be taken from the USER environment variable).
   3) By specifying the password in a file by name via PASSWD_FILE
   4) By specifying the password in a file by file descriptor via PASSWD_FD
   
   If no password is provided, mount.cifs will prompt for password entry
   
   Restrictions
   ============
   Servers must support either "pure-TCP" (port 445 TCP/IP CIFS connections) or RFC 
   1001/1002 support for "Netbios-Over-TCP/IP." This is not likely to be a 
   problem as most servers support this.
   
   Valid filenames differ between Windows and Linux.  Windows typically restricts
   filenames which contain certain reserved characters (e.g.the character : 
   which is used to delimit the beginning of a stream name by Windows), while
   Linux allows a slightly wider set of valid characters in filenames. Windows
   servers can remap such characters when an explicit mapping is specified in
   the Server's registry.  Samba starting with version 3.10 will allow such 
   filenames (ie those which contain valid Linux characters, which normally
   would be forbidden for Windows/CIFS semantics) as long as the server is
   configured for Unix Extensions (and the client has not disabled
   /proc/fs/cifs/LinuxExtensionsEnabled).
     
   
   CIFS VFS Mount Options
   ======================
   A partial list of the supported mount options follows:
     user          The user name to use when trying to establish
                   the CIFS session.
     password      The user password.  If the mount helper is
                   installed, the user will be prompted for password
                   if not supplied.
     ip            The ip address of the target server
     unc           The target server Universal Network Name (export) to 
                   mount.  
     domain        Set the SMB/CIFS workgroup name prepended to the
                   username during CIFS session establishment
     forceuid      Set the default uid for inodes to the uid
                   passed in on mount. For mounts to servers
                   which do support the CIFS Unix extensions, such as a
                   properly configured Samba server, the server provides
                   the uid, gid and mode so this parameter should not be
                   specified unless the server and clients uid and gid
                   numbering differ.  If the server and client are in the
                   same domain (e.g. running winbind or nss_ldap) and
                   the server supports the Unix Extensions then the uid
                   and gid can be retrieved from the server (and uid
                   and gid would not have to be specifed on the mount. 
                   For servers which do not support the CIFS Unix
                   extensions, the default uid (and gid) returned on lookup
                   of existing files will be the uid (gid) of the person
                   who executed the mount (root, except when mount.cifs
                   is configured setuid for user mounts) unless the "uid=" 
                   (gid) mount option is specified. Also note that permission
                   checks (authorization checks) on accesses to a file occur
                   at the server, but there are cases in which an administrator
                   may want to restrict at the client as well.  For those
                   servers which do not report a uid/gid owner
                   (such as Windows), permissions can also be checked at the
                   client, and a crude form of client side permission checking 
                   can be enabled by specifying file_mode and dir_mode on 
                   the client.  (default)
     forcegid      (similar to above but for the groupid instead of uid) (default)
     noforceuid    Fill in file owner information (uid) by requesting it from
                   the server if possible. With this option, the value given in
                   the uid= option (on mount) will only be used if the server
                   can not support returning uids on inodes.
     noforcegid    (similar to above but for the group owner, gid, instead of uid)
     uid           Set the default uid for inodes, and indicate to the
                   cifs kernel driver which local user mounted. If the server
                   supports the unix extensions the default uid is
                   not used to fill in the owner fields of inodes (files)
                   unless the "forceuid" parameter is specified.
     gid           Set the default gid for inodes (similar to above).
     file_mode     If CIFS Unix extensions are not supported by the server
                   this overrides the default mode for file inodes.
     fsc           Enable local disk caching using FS-Cache (off by default). This
                   option could be useful to improve performance on a slow link,
                   heavily loaded server and/or network where reading from the
                   disk is faster than reading from the server (over the network).
                   This could also impact scalability positively as the
                   number of calls to the server are reduced. However, local
                   caching is not suitable for all workloads for e.g. read-once
                   type workloads. So, you need to consider carefully your
                   workload/scenario before using this option. Currently, local
                   disk caching is functional for CIFS files opened as read-only.
     dir_mode      If CIFS Unix extensions are not supported by the server 
                   this overrides the default mode for directory inodes.
     port          attempt to contact the server on this tcp port, before
                   trying the usual ports (port 445, then 139).
     iocharset     Codepage used to convert local path names to and from
                   Unicode. Unicode is used by default for network path
                   names if the server supports it.  If iocharset is
                   not specified then the nls_default specified
                   during the local client kernel build will be used.
                   If server does not support Unicode, this parameter is
                   unused.
     rsize         default read size (usually 16K). The client currently
                   can not use rsize larger than CIFSMaxBufSize. CIFSMaxBufSize
                   defaults to 16K and may be changed (from 8K to the maximum
                   kmalloc size allowed by your kernel) at module install time
                   for cifs.ko. Setting CIFSMaxBufSize to a very large value
                   will cause cifs to use more memory and may reduce performance
                   in some cases.  To use rsize greater than 127K (the original
                   cifs protocol maximum) also requires that the server support
                   a new Unix Capability flag (for very large read) which some
                   newer servers (e.g. Samba 3.0.26 or later) do. rsize can be
                   set from a minimum of 2048 to a maximum of 130048 (127K or
                   CIFSMaxBufSize, whichever is smaller)
     wsize         default write size (default 57344)
                   maximum wsize currently allowed by CIFS is 57344 (fourteen
                   4096 byte pages)
     actimeo=n     attribute cache timeout in seconds (default 1 second).
                   After this timeout, the cifs client requests fresh attribute
                   information from the server. This option allows to tune the
                   attribute cache timeout to suit the workload needs. Shorter
                   timeouts mean better the cache coherency, but increased number
                   of calls to the server. Longer timeouts mean reduced number
                   of calls to the server at the expense of less stricter cache
                   coherency checks (i.e. incorrect attribute cache for a short
                   period of time).
     rw            mount the network share read-write (note that the
                   server may still consider the share read-only)
     ro            mount network share read-only
     version       used to distinguish different versions of the
                   mount helper utility (not typically needed)
     sep           if first mount option (after the -o), overrides
                   the comma as the separator between the mount
                   parms. e.g.
                           -o user=myname,password=mypassword,domain=mydom
                   could be passed instead with period as the separator by
                           -o sep=.user=myname.password=mypassword.domain=mydom
                   this might be useful when comma is contained within username
                   or password or domain. This option is less important
                   when the cifs mount helper cifs.mount (version 1.1 or later)
                   is used.
     nosuid        Do not allow remote executables with the suid bit 
                   program to be executed.  This is only meaningful for mounts
                   to servers such as Samba which support the CIFS Unix Extensions.
                   If you do not trust the servers in your network (your mount
                   targets) it is recommended that you specify this option for
                   greater security.
     exec          Permit execution of binaries on the mount.
     noexec        Do not permit execution of binaries on the mount.
     dev           Recognize block devices on the remote mount.
     nodev         Do not recognize devices on the remote mount.
     suid          Allow remote files on this mountpoint with suid enabled to 
                   be executed (default for mounts when executed as root,
                   nosuid is default for user mounts).
     credentials   Although ignored by the cifs kernel component, it is used by 
                   the mount helper, mount.cifs. When mount.cifs is installed it
                   opens and reads the credential file specified in order  
                   to obtain the userid and password arguments which are passed to
                   the cifs vfs.
     guest         Although ignored by the kernel component, the mount.cifs
                   mount helper will not prompt the user for a password
                   if guest is specified on the mount options.  If no
                   password is specified a null password will be used.
     perm          Client does permission checks (vfs_permission check of uid
                   and gid of the file against the mode and desired operation),
                   Note that this is in addition to the normal ACL check on the
                   target machine done by the server software. 
                   Client permission checking is enabled by default.
     noperm        Client does not do permission checks.  This can expose
                   files on this mount to access by other users on the local
                   client system. It is typically only needed when the server
                   supports the CIFS Unix Extensions but the UIDs/GIDs on the
                   client and server system do not match closely enough to allow
                   access by the user doing the mount, but it may be useful with
                   non CIFS Unix Extension mounts for cases in which the default
                   mode is specified on the mount but is not to be enforced on the
                   client (e.g. perhaps when MultiUserMount is enabled)
                   Note that this does not affect the normal ACL check on the
                   target machine done by the server software (of the server
                   ACL against the user name provided at mount time).
     serverino     Use server's inode numbers instead of generating automatically
                   incrementing inode numbers on the client.  Although this will
                   make it easier to spot hardlinked files (as they will have
                   the same inode numbers) and inode numbers may be persistent,
                   note that the server does not guarantee that the inode numbers
                   are unique if multiple server side mounts are exported under a
                   single share (since inode numbers on the servers might not
                   be unique if multiple filesystems are mounted under the same
                   shared higher level directory).  Note that some older
                   (e.g. pre-Windows 2000) do not support returning UniqueIDs
                   or the CIFS Unix Extensions equivalent and for those
                   this mount option will have no effect.  Exporting cifs mounts
                   under nfsd requires this mount option on the cifs mount.
                   This is now the default if server supports the 
                   required network operation.
     noserverino   Client generates inode numbers (rather than using the actual one
                   from the server). These inode numbers will vary after
                   unmount or reboot which can confuse some applications,
                   but not all server filesystems support unique inode
                   numbers.
     setuids       If the CIFS Unix extensions are negotiated with the server
                   the client will attempt to set the effective uid and gid of
                   the local process on newly created files, directories, and
                   devices (create, mkdir, mknod).  If the CIFS Unix Extensions
                   are not negotiated, for newly created files and directories
                   instead of using the default uid and gid specified on
                   the mount, cache the new file's uid and gid locally which means
                   that the uid for the file can change when the inode is
                   reloaded (or the user remounts the share).
     nosetuids     The client will not attempt to set the uid and gid on
                   on newly created files, directories, and devices (create, 
                   mkdir, mknod) which will result in the server setting the
                   uid and gid to the default (usually the server uid of the
                   user who mounted the share).  Letting the server (rather than
                   the client) set the uid and gid is the default. If the CIFS
                   Unix Extensions are not negotiated then the uid and gid for
                   new files will appear to be the uid (gid) of the mounter or the
                   uid (gid) parameter specified on the mount.
     netbiosname   When mounting to servers via port 139, specifies the RFC1001
                   source name to use to represent the client netbios machine 
                   name when doing the RFC1001 netbios session initialize.
     direct        Do not do inode data caching on files opened on this mount.
                   This precludes mmapping files on this mount. In some cases
                   with fast networks and little or no caching benefits on the
                   client (e.g. when the application is doing large sequential
                   reads bigger than page size without rereading the same data) 
                   this can provide better performance than the default
                   behavior which caches reads (readahead) and writes 
                   (writebehind) through the local Linux client pagecache 
                   if oplock (caching token) is granted and held. Note that
                   direct allows write operations larger than page size
                   to be sent to the server.
     strictcache   Use for switching on strict cache mode. In this mode the
                   client read from the cache all the time it has Oplock Level II,
                   otherwise - read from the server. All written data are stored
                   in the cache, but if the client doesn't have Exclusive Oplock,
                   it writes the data to the server.
     rwpidforward  Forward pid of a process who opened a file to any read or write
                   operation on that file. This prevent applications like WINE
                   from failing on read and write if we use mandatory brlock style.
     acl           Allow setfacl and getfacl to manage posix ACLs if server
                   supports them.  (default)
     noacl         Do not allow setfacl and getfacl calls on this mount
     user_xattr    Allow getting and setting user xattrs (those attributes whose
                   name begins with "user." or "os2.") as OS/2 EAs (extended
                   attributes) to the server.  This allows support of the
                   setfattr and getfattr utilities. (default)
     nouser_xattr  Do not allow getfattr/setfattr to get/set/list xattrs 
     mapchars      Translate six of the seven reserved characters (not backslash)
                           *?<>|:
                   to the remap range (above 0xF000), which also
                   allows the CIFS client to recognize files created with
                   such characters by Windows's POSIX emulation. This can
                   also be useful when mounting to most versions of Samba
                   (which also forbids creating and opening files
                   whose names contain any of these seven characters).
                   This has no effect if the server does not support
                   Unicode on the wire.
    nomapchars     Do not translate any of these seven characters (default).
    nocase         Request case insensitive path name matching (case
                   sensitive is the default if the server supports it).
                   (mount option "ignorecase" is identical to "nocase")
    posixpaths     If CIFS Unix extensions are supported, attempt to
                   negotiate posix path name support which allows certain
                   characters forbidden in typical CIFS filenames, without
                   requiring remapping. (default)
    noposixpaths   If CIFS Unix extensions are supported, do not request
                   posix path name support (this may cause servers to
                   reject creatingfile with certain reserved characters).
    nounix         Disable the CIFS Unix Extensions for this mount (tree
                   connection). This is rarely needed, but it may be useful
                   in order to turn off multiple settings all at once (ie
                   posix acls, posix locks, posix paths, symlink support
                   and retrieving uids/gids/mode from the server) or to
                   work around a bug in server which implement the Unix
                   Extensions.
    nobrl          Do not send byte range lock requests to the server.
                   This is necessary for certain applications that break
                   with cifs style mandatory byte range locks (and most
                   cifs servers do not yet support requesting advisory
                   byte range locks).
    forcemandatorylock Even if the server supports posix (advisory) byte range
                   locking, send only mandatory lock requests.  For some
                   (presumably rare) applications, originally coded for
                   DOS/Windows, which require Windows style mandatory byte range
                   locking, they may be able to take advantage of this option,
                   forcing the cifs client to only send mandatory locks
                   even if the cifs server would support posix advisory locks.
                   "forcemand" is accepted as a shorter form of this mount
                   option.
    nostrictsync   If this mount option is set, when an application does an
                   fsync call then the cifs client does not send an SMB Flush
                   to the server (to force the server to write all dirty data
                   for this file immediately to disk), although cifs still sends
                   all dirty (cached) file data to the server and waits for the
                   server to respond to the write.  Since SMB Flush can be
                   very slow, and some servers may be reliable enough (to risk
                   delaying slightly flushing the data to disk on the server),
                   turning on this option may be useful to improve performance for
                   applications that fsync too much, at a small risk of server
                   crash.  If this mount option is not set, by default cifs will
                   send an SMB flush request (and wait for a response) on every
                   fsync call.
    nodfs          Disable DFS (global name space support) even if the
                   server claims to support it.  This can help work around
                   a problem with parsing of DFS paths with Samba server
                   versions 3.0.24 and 3.0.25.
    remount        remount the share (often used to change from ro to rw mounts
                   or vice versa)
    cifsacl        Report mode bits (e.g. on stat) based on the Windows ACL for
                   the file. (EXPERIMENTAL)
    servern        Specify the server 's netbios name (RFC1001 name) to use
                   when attempting to setup a session to the server. 
                   This is needed for mounting to some older servers (such
                   as OS/2 or Windows 98 and Windows ME) since they do not
                   support a default server name.  A server name can be up
                   to 15 characters long and is usually uppercased.
    sfu            When the CIFS Unix Extensions are not negotiated, attempt to
                   create device files and fifos in a format compatible with
                   Services for Unix (SFU).  In addition retrieve bits 10-12
                   of the mode via the SETFILEBITS extended attribute (as
                   SFU does).  In the future the bottom 9 bits of the
                   mode also will be emulated using queries of the security
                   descriptor (ACL).
    mfsymlinks     Enable support for Minshall+French symlinks
                   (see http://wiki.samba.org/index.php/UNIX_Extensions#Minshall.2BFrench_symlinks)
                   This option is ignored when specified together with the
                   'sfu' option. Minshall+French symlinks are used even if
                   the server supports the CIFS Unix Extensions.
    sign           Must use packet signing (helps avoid unwanted data modification
                   by intermediate systems in the route).  Note that signing
                   does not work with lanman or plaintext authentication.
    seal           Must seal (encrypt) all data on this mounted share before
                   sending on the network.  Requires support for Unix Extensions.
                   Note that this differs from the sign mount option in that it
                   causes encryption of data sent over this mounted share but other
                   shares mounted to the same server are unaffected.
    locallease     This option is rarely needed. Fcntl F_SETLEASE is
                   used by some applications such as Samba and NFSv4 server to
                   check to see whether a file is cacheable.  CIFS has no way
                   to explicitly request a lease, but can check whether a file
                   is cacheable (oplocked).  Unfortunately, even if a file
                   is not oplocked, it could still be cacheable (ie cifs client
                   could grant fcntl leases if no other local processes are using
                   the file) for cases for example such as when the server does not
                   support oplocks and the user is sure that the only updates to
                   the file will be from this client. Specifying this mount option
                   will allow the cifs client to check for leases (only) locally
                   for files which are not oplocked instead of denying leases
                   in that case. (EXPERIMENTAL)
    sec            Security mode.  Allowed values are:
                           none    attempt to connection as a null user (no name)
                           krb5    Use Kerberos version 5 authentication
                           krb5i   Use Kerberos authentication and packet signing
                           ntlm    Use NTLM password hashing (default)
                           ntlmi   Use NTLM password hashing with signing (if
                                   /proc/fs/cifs/PacketSigningEnabled on or if
                                   server requires signing also can be the default) 
                           ntlmv2  Use NTLMv2 password hashing      
                           ntlmv2i Use NTLMv2 password hashing with packet signing
                           lanman  (if configured in kernel config) use older
                                   lanman hash
   hard            Retry file operations if server is not responding
   soft            Limit retries to unresponsive servers (usually only
                   one retry) before returning an error.  (default)
   
   The mount.cifs mount helper also accepts a few mount options before -o
   including:
   
           -S      take password from stdin (equivalent to setting the environment
                   variable "PASSWD_FD=0"
           -V      print mount.cifs version
           -?      display simple usage information
   
   With most 2.6 kernel versions of modutils, the version of the cifs kernel
   module can be displayed via modinfo.
   
   Misc /proc/fs/cifs Flags and Debug Info
   =======================================
   Informational pseudo-files:
   DebugData               Displays information about active CIFS sessions and
                           shares, features enabled as well as the cifs.ko
                           version.
   Stats                   Lists summary resource usage information as well as per
                           share statistics, if CONFIG_CIFS_STATS in enabled
                           in the kernel configuration.
   
   Configuration pseudo-files:
   PacketSigningEnabled    If set to one, cifs packet signing is enabled
                           and will be used if the server requires 
                           it.  If set to two, cifs packet signing is
                           required even if the server considers packet
                           signing optional. (default 1)
   SecurityFlags           Flags which control security negotiation and
                           also packet signing. Authentication (may/must)
                           flags (e.g. for NTLM and/or NTLMv2) may be combined with
                           the signing flags.  Specifying two different password
                           hashing mechanisms (as "must use") on the other hand 
                           does not make much sense. Default flags are 
                                   0x07007 
                           (NTLM, NTLMv2 and packet signing allowed).  The maximum 
                           allowable flags if you want to allow mounts to servers
                           using weaker password hashes is 0x37037 (lanman,
                           plaintext, ntlm, ntlmv2, signing allowed).  Some
                           SecurityFlags require the corresponding menuconfig
                           options to be enabled (lanman and plaintext require
                           CONFIG_CIFS_WEAK_PW_HASH for example).  Enabling
                           plaintext authentication currently requires also
                           enabling lanman authentication in the security flags
                           because the cifs module only supports sending
                           laintext passwords using the older lanman dialect
                           form of the session setup SMB.  (e.g. for authentication
                           using plain text passwords, set the SecurityFlags
                           to 0x30030):
    
                           may use packet signing                          0x00001
                           must use packet signing                         0x01001
                           may use NTLM (most common password hash)        0x00002
                           must use NTLM                                   0x02002
                           may use NTLMv2                                  0x00004
                           must use NTLMv2                                 0x04004
                           may use Kerberos security                       0x00008
                           must use Kerberos                               0x08008
                           may use lanman (weak) password hash             0x00010
                           must use lanman password hash                   0x10010
                           may use plaintext passwords                     0x00020
                           must use plaintext passwords                    0x20020
                           (reserved for future packet encryption)         0x00040
   
   cifsFYI                 If set to non-zero value, additional debug information
                           will be logged to the system error log.  This field
                           contains three flags controlling different classes of
                           debugging entries.  The maximum value it can be set
                           to is 7 which enables all debugging points (default 0).
                           Some debugging statements are not compiled into the
                           cifs kernel unless CONFIG_CIFS_DEBUG2 is enabled in the
                           kernel configuration. cifsFYI may be set to one or
                           nore of the following flags (7 sets them all):
   
                           log cifs informational messages                 0x01
                           log return codes from cifs entry points         0x02
                           log slow responses (ie which take longer than 1 second)
                             CONFIG_CIFS_STATS2 must be enabled in .config 0x04
                                   
                                   
   traceSMB                If set to one, debug information is logged to the
                           system error log with the start of smb requests
                           and responses (default 0)
   LookupCacheEnable       If set to one, inode information is kept cached
                           for one second improving performance of lookups
                           (default 1)
   OplockEnabled           If set to one, safe distributed caching enabled.
                           (default 1)
   LinuxExtensionsEnabled  If set to one then the client will attempt to
                           use the CIFS "UNIX" extensions which are optional
                           protocol enhancements that allow CIFS servers
                           to return accurate UID/GID information as well
                           as support symbolic links. If you use servers
                           such as Samba that support the CIFS Unix
                           extensions but do not want to use symbolic link
                           support and want to map the uid and gid fields 
                           to values supplied at mount (rather than the 
                           actual values, then set this to zero. (default 1)
   
   These experimental features and tracing can be enabled by changing flags in 
   /proc/fs/cifs (after the cifs module has been installed or built into the 
   kernel, e.g.  insmod cifs).  To enable a feature set it to 1 e.g.  to enable 
   tracing to the kernel message log type: 
   
           echo 7 > /proc/fs/cifs/cifsFYI
           
   cifsFYI functions as a bit mask. Setting it to 1 enables additional kernel
   logging of various informational messages.  2 enables logging of non-zero
   SMB return codes while 4 enables logging of requests that take longer
   than one second to complete (except for byte range lock requests). 
   Setting it to 4 requires defining CONFIG_CIFS_STATS2 manually in the
   source code (typically by setting it in the beginning of cifsglob.h),
   and setting it to seven enables all three.  Finally, tracing
   the start of smb requests and responses can be enabled via:
   
           echo 1 > /proc/fs/cifs/traceSMB
   
   Per share (per client mount) statistics are available in /proc/fs/cifs/Stats
   if the kernel was configured with cifs statistics enabled.  The statistics
   represent the number of successful (ie non-zero return code from the server) 
   SMB responses to some of the more common commands (open, delete, mkdir etc.).
   Also recorded is the total bytes read and bytes written to the server for
   that share.  Note that due to client caching effects this can be less than the
   number of bytes read and written by the application running on the client.
   The statistics for the number of total SMBs and oplock breaks are different in
   that they represent all for that share, not just those for which the server
   returned success.
           
   Also note that "cat /proc/fs/cifs/DebugData" will display information about
   the active sessions and the shares that are mounted.
   
   Enabling Kerberos (extended security) works but requires version 1.2 or later
   of the helper program cifs.upcall to be present and to be configured in the
   /etc/request-key.conf file.  The cifs.upcall helper program is from the Samba
   project(http://www.samba.org). NTLM and NTLMv2 and LANMAN support do not
   require this helper. Note that NTLMv2 security (which does not require the
   cifs.upcall helper program), instead of using Kerberos, is sufficient for
   some use cases.
   
   DFS support allows transparent redirection to shares in an MS-DFS name space.
   In addition, DFS support for target shares which are specified as UNC
   names which begin with host names (rather than IP addresses) requires
   a user space helper (such as cifs.upcall) to be present in order to
   translate host names to ip address, and the user space helper must also
   be configured in the file /etc/request-key.conf.  Samba, Windows servers and
   many NAS appliances support DFS as a way of constructing a global name
   space to ease network configuration and improve reliability.
   
   To use cifs Kerberos and DFS support, the Linux keyutils package should be
   installed and something like the following lines should be added to the
   /etc/request-key.conf file:
   
   create cifs.spnego * * /usr/local/sbin/cifs.upcall %k
   create dns_resolver * * /usr/local/sbin/cifs.upcall %k
   
   CIFS kernel module parameters
   =============================
   These module parameters can be specified or modified either during the time of
   module loading or during the runtime by using the interface
           /proc/module/cifs/parameters/<param>
   
   i.e. echo "value" > /sys/module/cifs/parameters/<param>
   
   1. enable_oplocks - Enable or disable oplocks. Oplocks are enabled by default.
                       [Y/y/1]. To disable use any of [N/n/0].