SELinux: Add new security mount option to indicate security label support.

There is no easy way to tell if a file system supports SELinux security labeling.
Because of this a new flag is being added to the super block security structure
to indicate that the particular super block supports labeling. This flag is set
for file systems using the xattr, task, and transition labeling methods unless
that behavior is overridden by context mounts.

Signed-off-by: David P. Quigley <dpquigl@tycho.nsa.gov>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@macbook.localdomain>
diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h
index ff4e19c..e1d9db7 100644
--- a/security/selinux/include/security.h
+++ b/security/selinux/include/security.h
@@ -47,11 +47,13 @@
 /* Non-mount related flags */
 #define SE_SBINITIALIZED	0x10
 #define SE_SBPROC		0x20
+#define SE_SBLABELSUPP	0x40
 
 #define CONTEXT_STR	"context="
 #define FSCONTEXT_STR	"fscontext="
 #define ROOTCONTEXT_STR	"rootcontext="
 #define DEFCONTEXT_STR	"defcontext="
+#define LABELSUPP_STR "seclabel"
 
 struct netlbl_lsm_secattr;