Re: [PATCHv2 2/2] scsi: set timed out out mq requests to complete

[Keith Busch <keith.busch@linux.intel.com>]

On Tue, Jul 24, 2018 at 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().