Re: [Libguestfs] [nbdkit PATCH 3/7] RFC: protocol: Only send EOVERFLOW when valid

[adding NBD list] On 4/23/19 2:36 AM, Richard W.M. Jones wrote: > On Mon, Apr 22, 2019 at 07:50:22PM -0500, Eric Blake wrote: >> Previously, we were squashing EOVERFLOW into EINVAL; continue to do so >> at points in the protocol where the client may not be expecting >> EOVERFLOW. > > The protocol spec is unclear on whether EOVERFLOW can be returned in > cases other than the DF flag being set. Whether we include this patch > or not seems to hinge on the interpretation of the protocol spec which > I'm not really in a position to make.

So the question at hand is whether I should patch the NBD spec to recommend that a server SHOULD NOT send EOVERFLOW except in response to NBD_CMD_READ when the NBD_CMD_FLAG_DF bit is set (similar to my proposed wording that a server SHOULD NOT send ENOTSUP except in response to NBD_CMD_FLAG_FAST_ZERO).