Re: eh_abort_handler and calling scsi_done

Brian King
2009-03-24T13:29:45Z

Your assessment sounds correct to me. The other caveat to note is that
if for some reason in your eh_abort_handler you don't think the command
is still outstanding, you should return SUCCESS for this as well.

-Brian

Christof Schmitt wrote:
> 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?
>
> --
> Christof Schmitt
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--
Brian King
Linux on Power Virtualization
IBM Linux Technology Center