fix encryption error checks on mount

Signed-off-by: Steve French <steve.french@primarydata.com>
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index e543431..ce83e2e 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -922,6 +922,12 @@
 	if (tcon && tcon->bad_network_name)
 		return -ENOENT;
 
+	if ((tcon->seal) &&
+	    ((ses->server->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION) == 0)) {
+		cifs_dbg(VFS, "encryption requested but no server support");
+		return -EOPNOTSUPP;
+	}
+
 	unc_path = kmalloc(MAX_SHARENAME_LENGTH * 2, GFP_KERNEL);
 	if (unc_path == NULL)
 		return -ENOMEM;
@@ -1001,6 +1007,8 @@
 	    ((tcon->share_flags & SHI1005_FLAGS_DFS) == 0))
 		cifs_dbg(VFS, "DFS capability contradicts DFS flag\n");
 	init_copy_chunk_defaults(tcon);
+	if (tcon->share_flags & SHI1005_FLAGS_ENCRYPT_DATA)
+		cifs_dbg(VFS, "Encrypted shares not supported");
 	if (tcon->ses->server->ops->validate_negotiate)
 		rc = tcon->ses->server->ops->validate_negotiate(xid, tcon);
 tcon_exit: