From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Anderson Subject: Re: eh_abort_handler and calling scsi_done Date: Tue, 24 Mar 2009 10:46:09 -0700 Message-ID: <20090324174609.GA13556@linux.vnet.ibm.com> References: <20090324114137.GA8616@schmichrtp.de.ibm.com> <49C8E055.2060108@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from e9.ny.us.ibm.com ([32.97.182.139]:42905 "EHLO e9.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755385AbZCXRqM (ORCPT ); Tue, 24 Mar 2009 13:46:12 -0400 Received: from d01relay04.pok.ibm.com (d01relay04.pok.ibm.com [9.56.227.236]) by e9.ny.us.ibm.com (8.13.1/8.13.1) with ESMTP id n2OHaxIb008183 for ; Tue, 24 Mar 2009 13:36:59 -0400 Received: from d01av03.pok.ibm.com (d01av03.pok.ibm.com [9.56.224.217]) by d01relay04.pok.ibm.com (8.13.8/8.13.8/NCO v9.2) with ESMTP id n2OHkA3n163050 for ; Tue, 24 Mar 2009 13:46:10 -0400 Received: from d01av03.pok.ibm.com (loopback [127.0.0.1]) by d01av03.pok.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id n2OHkAY5015693 for ; Tue, 24 Mar 2009 13:46:10 -0400 Content-Disposition: inline In-Reply-To: <49C8E055.2060108@linux.vnet.ibm.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Brian King Cc: Christof Schmitt , linux-scsi@vger.kernel.org Brian King wrote: > 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: > > > > <> > > > > 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). > > In cases 1 and 2 above calling scsi_done can be done but will cause the request to be stopped in blk_complete_request (scsi_done->blk_complete_request) as the timed out handler has already taken ownership of the command. -andmike -- Michael Anderson andmike@linux.vnet.ibm.com