SELinux: Unify context mount and genfs behavior

Context mounts and genfs labeled file systems behave differently with respect to
setting file system labels. This patch brings genfs labeled file systems in line
with context mounts in that setxattr calls to them should return EOPNOTSUPP and
fscreate calls will be ignored.

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/hooks.c b/security/selinux/hooks.c
index 1a9768a..3bb4942 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -1613,7 +1613,7 @@
 	if (rc)
 		return rc;
 
-	if (!newsid || sbsec->behavior == SECURITY_FS_USE_MNTPOINT) {
+	if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) {
 		rc = security_transition_sid(sid, dsec->sid, tclass, &newsid);
 		if (rc)
 			return rc;
@@ -2597,7 +2597,7 @@
 	sid = tsec->sid;
 	newsid = tsec->create_sid;
 
-	if (!newsid || sbsec->behavior == SECURITY_FS_USE_MNTPOINT) {
+	if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) {
 		rc = security_transition_sid(sid, dsec->sid,
 					     inode_mode_to_security_class(inode->i_mode),
 					     &newsid);
@@ -2619,7 +2619,7 @@
 		isec->initialized = 1;
 	}
 
-	if (!ss_initialized || sbsec->behavior == SECURITY_FS_USE_MNTPOINT)
+	if (!ss_initialized || !(sbsec->flags & SE_SBLABELSUPP))
 		return -EOPNOTSUPP;
 
 	if (name) {
@@ -2796,7 +2796,7 @@
 		return selinux_inode_setotherxattr(dentry, name);
 
 	sbsec = inode->i_sb->s_security;
-	if (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)
+	if (!(sbsec->flags & SE_SBLABELSUPP))
 		return -EOPNOTSUPP;
 
 	if (!is_owner_or_cap(inode))