ISCSI: Unsolicited data in draft v12

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

	I propose we slightly relax the new restriction in draft v12 that the
initiator MUST send the maximum permissible amount of unsolicited data. I
suggest we change the rule to allow the initiator to either send no
unsolicited data, or the maximum permissible.

	There is no difficulty for the target here since the lack of unsolicited
data will be clearly indicated by a command PDU with F bit set and
dataSegLen=0. The target will have all the information it needs to
immediately issue R2Ts as appropriate.

	I believe the initiator should be able to make a policy decision on which
individual commands should be sent with unsolicited data and which should
not.

	In draft 11.91 section 2.2.4 I suggest we change

"An iSCSI initiator MUST send as unsolicited data either the negotiated
amount or all the data if the total amount is less than the negotiated
amount for unsolicited data."

	to something like

"An iSCSI initiator MAY choose to send no unsolicited data with a command,
or if any unsolicited data is sent it MUST be either the negotiated amount
or all the data if the total amount is less than the negotiated amount for
unsolicited data."

	- Rod