eh_abort_handler and calling scsi_done

Christof Schmitt
2009-03-24T11:41:40Z

I am investigating what is required from a LLD when SCSI commands time
out and the SCSI EH calls the eh_abort_handler. The documentation in
scsi_eh.txt states:

<<scsi_eh_abort_cmds>>

This action is taken for each timed out command.
hostt->eh_abort_handler() is invoked for each scmd. The
handler returns SUCCESS if it has succeeded to make LLDD and
all related hardware forget about the scmd.

>From this and from looking at the code, i would conclude:

1) If the LLD returns FAILED from the eh_abort_handler, then the
command is still allowed to be active in the LLD and the LLD can
call scsi_done any time later (probably latest when the
eh_host_reset_handler flushes everything that is still pending).

2) While the abort is pending, but before returning SUCCESS from
eh_abort_handler, the LLD can still call scsi_done for the SCSI
command to be aborted (the SCSI command might be returned with a
status "aborted" if the abort succeeds, or "good" if it was
completed just before the abort reached the storage system).

Is this correct? Are there any more limitations a SCSI LLD has to be
aware of?