From: Lee Duncan <lduncan@xxxxxxxx>
Some iSCSI initiators send SCSI PDUs with the "immediate" bit
set, and this is allowed according to RFC 3720. Commands with
the "Immediate" bit set are called "immediate commands". From
section 3.2.2.1. "Command Numbering and Acknowledging":
The target MUST NOT transmit a MaxCmdSN that is less than
ExpCmdSN-1. For non-immediate commands, the CmdSN field can take any
value from ExpCmdSN to MaxCmdSN inclusive. The target MUST silently
ignore any non-immediate command outside of this range or non-
immediate duplicates within the range. The CmdSN carried by
immediate commands may lie outside the ExpCmdSN to MaxCmdSN range.
For example, if the initiator has previously sent a non-immediate
command carrying the CmdSN equal to MaxCmdSN, the target window is
closed. For group task management commands issued as immediate
commands, CmdSN indicates the scope of the group action (e.g., on
ABORT TASK SET indicates which commands are aborted).
This fixed an issue with fastlinq qedi Converged Network Adapter
initiator firmware, trying to use an LIO target for booting. These
changes made booting possible, with or without ImmediateData enabled.