[CIFS] UID/GID override on CIFS mounts to Samba

When CIFS Unix Extensions are negotiated we get the Unix uid and gid
owners of the file from the server (on the Unix Query Path Info
levels), but if the server's uids don't match the client uid's users
were having to disable the Unix Extensions (which turned off features
they still wanted).   The changeset patch allows users to override uid
and/or gid for file/directory owner with a default uid and/or gid
specified at mount (as is often done when mounting from Linux cifs
client to Windows server).  This changeset also displays the uid
and gid used by default in /proc/mounts (if applicable).

Also cleans up code by adding some of the missing spaces after
"if" keywords per-kernel style guidelines (as suggested by Randy Dunlap
when he reviewed the patch).

Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 14 insertions, 9 deletions

diff --git a/fs/cifs/README b/fs/cifs/README
index 080c5eba112b..93fe3594274f 100644
--- a/fs/cifs/README
+++ b/fs/cifs/README
@@ -257,13 +257,19 @@ A partial list of the supported mount options follows:
                 mount.  
   domain        Set the SMB/CIFS workgroup name prepended to the
                 username during CIFS session establishment
-  uid           If CIFS Unix extensions are not supported by the server
-                this overrides the default uid for inodes. 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.  For servers which do not support
-                the Unix extensions, the default uid (and gid) returned on
-                lookup of existing files is the uid (gid) of the person
+  uid           Set the default uid for inodes. 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.  For the uid (gid) of newly
@@ -281,8 +287,7 @@ A partial list of the supported mount options follows:
                 the client.  Note that the mount.cifs helper must be
                 at version 1.10 or higher to support specifying the uid
                 (or gid) in non-numberic form.
-  gid           If CIFS Unix extensions are not supported by the server
-                this overrides the default gid for inodes.
+  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.
   dir_mode      If CIFS Unix extensions are not supported by the server