[dm-devel] Re: [PATCH RFC 0/4] use scatter lists for all block pc requests and simplify hw handlers

Jens Axboe axboe at suse.de
Thu Jun 9 11:54:33 UTC 2005


On Thu, Jun 09 2005, James Bottomley wrote:
> On Thu, 2005-06-09 at 08:18 +0200, Jens Axboe wrote:
> > > So use a req->retries instead of the fail fast flag?
> > 
> > Would be fine. Some drivers are messing with ->errors for that anyways,
> > so would be nice to clean that up.
> > 
> > It would need to be done _very_ carefully though!
> 
> Actually, I think there's still a need for both.  Fail fast implies more
> than simply no retry.  In the SCSI case it should eventually mean fail
> the command before we begin transport recovery (at the moment, we simply
> use the command in transport recovery, however long it takes, and then
> return the failure).

I tend to agree, FAILFAST does have a use outside of normal retry logic.

-- 
Jens Axboe




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