ubifs: Implement directory open operation

We need the ->open() hook to load the crypto context
which is needed for all crypto operations within that
directory.
Signed-off-by: Richard Weinberger <richard@nod.at>

fs/ubifs/dir.c

@@ -1410,6 +1410,14 @@ int ubifs_getattr(struct vfsmount *mnt, struct dentry *dentry,
 	return 0;
 }
 
+static int ubifs_dir_open(struct inode *dir, struct file *file)
+{
+	if (ubifs_crypt_is_encrypted(dir))
+		return fscrypt_get_encryption_info(dir) ? -EACCES : 0;
+
+	return 0;
+}
+
 const struct inode_operations ubifs_dir_inode_operations = {
 	.lookup      = ubifs_lookup,
 	.create      = ubifs_create,
@@ -1436,6 +1444,7 @@ const struct file_operations ubifs_dir_operations = {
 	.iterate_shared = ubifs_readdir,
 	.fsync          = ubifs_fsync,
 	.unlocked_ioctl = ubifs_ioctl,
+	.open		= ubifs_dir_open,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl   = ubifs_compat_ioctl,
 #endif