[CIFS] Fix oops in cifs_create when nfsd server exports cifs mount

nfsd is passing null nameidata (probably the only one doing that)
on call to create - cifs was missing one check for this.

Note that running nfsd over a cifs mount requires specifying fsid on
the nfs exports entry and requires mounting cifs with serverino mount
option.

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

1 files changed, 6 insertions, 7 deletions

diff --git a/fs/cifs/README b/fs/cifs/README
index eb3efd5a6a81..85f1eb14083e 100644
--- a/fs/cifs/README
+++ b/fs/cifs/README
@@ -370,7 +370,7 @@ A partial list of the supported mount options follows:
                 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 servers inode numbers instead of generating automatically
+  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,
@@ -378,12 +378,11 @@ A partial list of the supported mount options follows:
                 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 this requires that
-                the server support the CIFS Unix Extensions as other servers
-                do not return a unique IndexNumber on SMB FindFirst (most
-                servers return zero as the IndexNumber).  Parameter has no
-                effect to Windows servers and others which do not support the
-                CIFS Unix Extensions.
+                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.
   noserverino   Client generates inode numbers (rather than using the actual one
                 from the server) by default.
   setuids       If the CIFS Unix extensions are negotiated with the server