NFS: use secinfo when crossing mountpoints

A submount may use different security than the parent
mount does.  We should figure out what sec flavor the
submount uses at mount time.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 3f32bf1..fa1ba78 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -82,6 +82,7 @@
 #define NFS_ATTR_FATTR_CHANGE		(1U << 17)
 #define NFS_ATTR_FATTR_PRECHANGE	(1U << 18)
 #define NFS_ATTR_FATTR_V4_REFERRAL	(1U << 19)	/* NFSv4 referral */
+#define NFS_ATTR_FATTR_MOUNTPOINT	(1U << 20)	/* Treat as mountpoint */
 
 #define NFS_ATTR_FATTR (NFS_ATTR_FATTR_TYPE \
 		| NFS_ATTR_FATTR_MODE \