[dm-devel] [PATCH v5] dm mpath: avoid call to blk_abort_queue by default

[Mike Anderson]

Alasdair G Kergon <agk at redhat.com> wrote:
> On Thu, Nov 18, 2010 at 03:07:33PM -0500, Mike Snitzer wrote:
> > It is expected that this race will be fixed in the near-term so it makes
> > little since to remove all associated code.  Providing control over the
> > call to blk_abort_queue() facilitates continued testing and future
> > flexibility to opt-in to lower latency path deactivation.  Opting to
> > enable this feature will emit a warning for the time being.
> 
> Ah, but then the *feature* keyword - which is only going to be needed
> temporarily until it's fixed - becomes a permanent part of the interface...
> 
> If it's broken, let's just disable it (#define-style) until it gets fixed.
> (And only if it doesn't get fixed in a reasonable amount of time, remove the
> code.)

I understand that if its broken that we could #define it out in dm or we
could #define the code in blk_abort_queue.

I believe the thought was that post addressing the race issue that
others may want control. As there maybe cases where the waking up of the
error_handler and a extra abort may not be wanted in all cases. 

-andmike
--
Michael Anderson
andmike at linux.vnet.ibm.com