RE: iSCSI: plugfest4 issues

["Rod Harrison" <rod.harrison@windriver.com>]

	With a tape in variable block mode a GOOD SCSI status and short read,
i.e. underflow is possible. Similarly with mode sense, or inquiry
etc., and a buffer that is too small there would be GOOD status and an
overflow indication. So the target does need to set the resid count
and bits when there is GOOD status.

	- Rod

				--- >8 ---

[snip ]

1. A question about whether or not the Residual Count field and the
   appropriate O and U bits need to be computed on all SCSI Response
   PDUs, regardless of the values in the Status and/or Response
fields.

   One point of view says that the Residual Count field and the O and
U
   bits appear to be strictly iSCSI values that are derived by the
   iSCSI target layer from the ExpectedDataTransferLength field of the
   SCSI Command PDU and the DataSegmentLength fields of the DataIn or
   DataOut PDUs sent as part of this command.  Therefore ,the iSCSI
   target always computes a Residual Count value without regard to the
   Status and/or Response fields, since these are SCSI values.

   The other point of view says that the Residual Count field, and the
   O and U bits, need only be set when the Status and Response fields
   indicate that the command was completed at the target with a GOOD
   Status, and the target does not have to compute or set the Residual
   Count field and the O or U bits for other values of the Status
and/or
   Response fields.

   Which is it?  In any case, could this be clarified somewhere in the
   standard, most likely in section 9.4.4.

[snip]