Out of curiosity, I took a look at how the MinimumBytes (actually MinimumCount) field is used by the Windows SMB server. Interestingly, it fails with STATUS_END_OF_FILE if the actual bytes read is less than MinimumCount, which suggests to me that this is supposed to be a minimum on the (remaining) file length, not on the number of bytes that the server is able to return at the moment.
I can't find any history of MinimumCount being used in the RTM version of any Windows SMB client, so without deeper archeology the reason this field was introduced remains a mystery to me.
Regardless, I agree that the client should validate the returned byte count. But (only having thought about this briefly), I do not think a client should retry in this case--it seems to me if the client sees a short read, it can assume that the read was short because the read reached EOF (which may have changed since the file's length was queried).
I can't find any history of MinimumCount being used in the RTM version of any Windows SMB client, so without deeper archeology the reason this field was introduced remains a mystery to me.
Regardless, I agree that the client should validate the returned byte count. But (only having thought about this briefly), I do not think a client should retry in this case--it seems to me if the client sees a short read, it can assume that the read was short because the read reached EOF (which may have changed since the file's length was queried).