Whenever a client gets a short read it needs to issue a request at the missing offset if the caller wanted more bytes. Only if the server returns zero on that read can it assume EOF and concurrent truncation.

We're going to have to fix the Samba server to never return short reads when using io_uring because the clients with this bug are already out there. But if what you're saying is how Microsoft expects the protocol to operate then it needs to be documented in MS-SMB2 because I don't think it's specified this way at the moment.