Christian Brauner <christian@xxxxxxxxxx> wrote: > > + ret = mutex_lock_interruptible(&fc->uapi_mutex); > > + if (ret == 0) { > > + ret = -EIO; > > Why EIO when there's no root dentry? Because I don't want to use ENODATA/EBADF and preferably not EINVAL and because the context you're accessing isn't in the correct state for you to be able to do that. How about EBADFD ("File descriptor in bad state")? David