From mboxrd@z Thu Jan  1 00:00:00 1970
From: keith.busch@linux.intel.com (Keith Busch)
Date: Tue, 24 Jul 2018 19:15:44 -0600
Subject: [PATCHv2 2/2] scsi: set timed out out mq requests to complete
In-Reply-To: <86e23e58-6f80-7957-30f7-8b0ce8cb50ce@wdc.com>
References: <20180723143751.10843-1-keith.busch@intel.com>
 <20180723143751.10843-2-keith.busch@intel.com>
 <86e23e58-6f80-7957-30f7-8b0ce8cb50ce@wdc.com>
Message-ID: <20180725011543.GA14596@localhost.localdomain>

On Tue, Jul 24, 2018@03:46:17PM -0700, Bart Van Assche wrote:
> On 07/23/18 07:37, Keith Busch wrote:
> > +		if (req->q->mq_ops && !blk_mq_mark_complete(req))
> > +			return rtn;
> >   		if (scsi_abort_command(scmd) != SUCCESS) {
> >   			set_host_byte(scmd, DID_TIME_OUT);
> >   			scsi_eh_scmd_add(scmd);
> 
> This change looks incomplete to me. I think the following scenario is not
> handled properly by the above patch:
> - host->hostt->eh_timed_out() gets called.
> - The request "req" completes from another context while
>   host->hostt->eh_timed_out() is in progress.
> - host->hostt->eh_timed_out() calls scsi_finish_command().
> 
> I think that scenario will lead to a double completion.

A bit of a moot point, isn't it? Not a single scsi lld directly calls
scsi_finish_command() from anywhere, much less through eh_timed_out().